The authors Page Flood risk and associated losses can only be understood and Brody Lee, Kothuis, eventually reduced through integrated investigation across NSF-PIRE Almarshed, Badreyah 33 multiple disciplines, cultures, and international boundaries. This Anarde, Katherine 45 approach entails combining physical and social science data, Andress, Randall 69 methods, and analytical techniques to form a more comprehensive COASTAL FLOOD RISK REDUCTION PROGRAM Atoba, Kayode 115 understanding of flood risk. With this systems approach in mind, Barrow, George 243 we proposed and were awarded the National Science Foundation Bass, Benjamin 103 PIRE grant to establish the Flood Risk Reduction Program. This Bennett, Madison 237 is a five-year project involving integrated research, place-based Bernier, Carl 171 education, and student exchange between multiple institutions in Brody, Samuel 5 the Netherlands and the United States. AUTHENTIC LEARNING AND TRANSFORMATIVE EDUCATION Brown, Joshua 91

Bu, Lei 179 The pages of this book are filled with the results of participating I VOLUME - EDUCATION TRANSFORMATIVE AND LEARNING AUTHENTIC COASTALNSF-PIRE FLOOD RISK REDUCTION PROGRAM Carlson, Brandee 39 student research projects in the first two years of the program. VOLUME I - 2015-2017 Diop, Fatimata 83 They cover a range of issues, from engineering and landscape Dittmar, Deirdra 203 design, to wave modeling and risk communication. Together they Do, Connie 211 represent a transdisciplinary and holistic approach to addressing Faizi, Rahmatullah 75 flood problems in the Netherlands and the U.S. While each project Fucile Sanchez, Emily 185 is an individual effort, they were produced through collaborated Gori, Avantika 123 exchange and information sharing at specific case study sites. This Herkes, Dominique 163 approach is what makes for a truly authentic learning experience Jeziersky, Bella 218 and is the only way to effectively address flood problems over the Kameshwar, Sabarethinam 51 long term. Malecha, Matthew 59 Parker, Alaina 151 Reinert, Sarah 135 Seong, Ki Jin 141 Whitley, Andrew 195 Yu, Siyu 227

EDITED BY Bee Kothuis Yoonjeong Lee Samuel Brody

Boekblok 245 x 220 mm, paperback met flappen van 150 mm; rug 15 mm PIRE 2016-17 cover to printer.indd 1 30-03-18 06:56 NSF-PIRE COASTAL FLOOD RISK REDUCTION PROGRAM

AUTHENTIC LEARNING AND TRANSFORMATIVE EDUCATION

VOLUME I - 2015-2017

by

Baukje ‘Bee’ Kothuis - Yoonjeong Lee - Samuel Brody

NATIONAL SCIENCE FOUNDATION PARTNERSHIPS FOR INTERNATIONAL RESEARCH AND EDUCATION (NSF-PIRE)

1 Figure right: Flood prone area in The Netherlands Samuel B. Brody NSF-PIRE Flood Risk Reduction Program Land below NAP/MSL: 26% case study areas INTEGRATED TRANSDISCIPLINARY EDUCATION AND RESEARCH as located in the Land above NAP/MSL: 29% flood prone area in the Netherlands (map courtesy of PREFACE Planbureau voor de Unembanked land: 3% Leefomgeving). Unembanked land along Meuse: 1% Dr. Samuel D. Brody storm was the third time in three years their thrive in a flood-prone landscape, there is no is PI of the NSF- PIRE residential structure was flooded. Rising better place to turn than the Netherlands. Flood Risk Reduction losses from storm after storm bring to light The Dutch are considered the world leaders NSF-PIRE Case study regions Program; Professor the notion that floods pose a major risk to in flood risk research, education, and of Marine Sciences the property and safety of local communities mitigation strategies. Working with and and Urban Planning at and despite ad hoc attempts to mitigate the learning from the brightest minds from a Texas A&M University; impacts, the problem appears to be getting country that has set the benchmark for flood and Director of the worse. mitigation and protection is one of the best Lake IJssel Center or Texas ways to address our national problem in Region Beaches and Shores What has also become clear, is that the rising the U.S. (CTBS). cost of floods is not solely a function of changing weather patterns or a problem that As we enter the third year of the Flood Risk can be solved through engineering solutions Reduction Research and Education program, Floods have emerged as the most disruptive alone. Rather, flood risk and associated losses it is amazing to see how far we have come! natural hazard in the United States (U.S.) can only be understood and eventually Over 30 students from multiple universities and an issue of national significance for reduced through integrated investigation have had transformative educational protecting the economy and vitality of local across multiple disciplines, cultures, and experiences in the Netherlands. Moreover, the Rotterdam communities over the long term. Increasing international boundaries. This approach program has spawned innovative research physical risk combined with rapid land use entails combining physical and social science methods, improved understanding of flood change and development in flood-prone data, methods, and analytical techniques to risk reduction, and generated mitigation areas has amplified the adverse economic form a more comprehensive understanding techniques that can be applied to Houston and human impacts in recent years. Never of flood risk. and other coastal urban areas across the U.S. before have the repercussions from storm Southwest events driven by both surge and rainfall With this systems approach in mind, we The pages of this book are filled with the Delta been so damaging. Losses from both acute proposed and were awarded the National results of participating student research and chronic flood events are especially Science Foundation PIRE grant to establish projects. They cover a range of issues, from problematic on the upper Texas coast, where the Flood Risk Reduction Program. This engineering and landscape design, to wave development in low-lying coastal areas has is a five-year project involving integrated modeling and risk communication. Together accelerated over the last several decades. research, place-based education, and student they represent a transdisciplinary and holistic Indeed, only six months ago, Hurricane exchange between multiple institutions approach to addressing flood problems in the Harvey brought record rainfall to the Texas in the Netherlands and the United States. Netherlands and the U.S. While each project coast, causing catastrophic losses to an area Focusing on the upper Texas Coast, students is an individual effort, they were produced covering 49 counties—20% of counties in and faculty transport lessons learned from through collaborated exchange and the State. Initial reports estimate that over the Netherlands to better understand how information sharing at specific case study 150,000 residential structures were inundated to reduce flood risk and impact in what sites. This approach is what makes for a truly by flood waters and damage estimates range has become the most flood impacted authentic learning experience and is the only in the 100’s of billions of dollars. metropolitan area in the U.S. The program way to effectively address flood problems is driven by the recognition that there is over the long term. While Harvey may have been a meteorologically- a critical need for program-level, trans- rare storm event, it exposed an underlying disciplinary inquiry that will lay a foundation problem of chronic and repetitive flooding for decision making aimed at increasing that impacts metropolitan areas like Houston the resiliency of coastal communities in on a regular basis. For many households in Texas, the U.S. and around the world. When 2 the Houston metro area, for example, the understanding how to effectively live and 3 ACKNOWLEDGEMENTS

The many and very diverse reserach and a wide range of organizations in The Defacto Architecture & Urbanism, Rotterdam; projects of the NSF PIRE Coastal Flood Risk Netherlands that provided our students Bureau StadsStromen, Amsterdam; Reduction Program which are presented in with data for their research cases, granted HKV Lijn in water, Lelystad; this publication would not have been possible interviews and facility visits, and/or provided Horvat, Delft; without the support of multiple organizations them with space to work and study: RHDHV, Rotterdam; and individuals. IVinfra, Sliedrecht; Rotterdam Port Authority; Deltares, Delft; For their continued and highly valued Municipality of Rotterdam; UNESCO-IHE, Delft; support and collaboration on a variety of Municipality of Almere; Delft Science Center, Delft. topics and challenges, we’d like to thank: Municipality of Vlissingen; Municipality of Nijmegen; Special thanks to Dr. Jill Slinger for The U.S. National Science Foundation Waternet, Amsterdam; co-designing and conducting both (grant no. 1545837) and the Partnerships for Hoogheemraadschap Hollands Noorder ‘TX meets TX’ and ‘TX meets HPZ’ International Research and Education (PIRE) Kwartier, Heerhugowaard; multidisciplinary design workshops. program team; Waterschap Zuiderzeeland, Lelystad; Waterschap Scheldestromen; Faculty, staff and students from Rijkswaterstaat; Texas A&M University, Galveston campus; Cafe Waalzicht, Lent; Texas A&M University, College Station Cafe De Zon, Lent; campus; Strandpaviljoen Zee & Zo, Petten; Rice University, Houston; Strandpaviljoen Paal 9, Den Hoorn; Jackson State University, Jackson, Mississippi; Dorpsraad, Petten; Delft University of Technology, Delft; Wieringen Prins Hoveniers, Amsterdam; VU University, Amsterdam, The Netherlands; Witteveen+Bos, Utrecht;

Figure (left): Hurricane Ike at 1:50 p.m. CDT on September 10, 2008. (Photo Courtesy 4 NASA). 5 2016 NSF-PIRE student group with Dutch students and co-PI’s at CONTENTS ‘Texas-meets-Texel Multidisciplinary Design Workshop’, Delft, May 31, 2016.

PREFACE 3 INTEGRATED TRANSDISCIPLINARY EDUCATION AND RESEARCH Samuel D. Brody, PI 5 ACKNOWLEDGEMENTS

ONE 11 EDUCATION, RESEARCH AND OUTREACH

EDUCATION 13 AUTHENTIC LEARNING AND TRANSFORMATIVE EDUCATION 17 INTERNATIONAL MULTIDISCIPLINARY DESIGN WORKSHOPS 21 STUDENTS’ TESTIMONIALS

RESEARCH APPROACH 23 INTEGRATED, MULTI-SCALE APPROACHES 25 AN INTEGRATED RESEARCH FRAMEWORK 27 THE FLOOD RISK REDUCTION PARTNERSHIP

OUTREACH 29 INFORMATION DISSEMINATION

THREE 31 STUDENT RESEARCH REPORTS 2016

SOUTHWEST DELTA 33 HYBRID COASTAL STRUCTURES Badreyah E. Almarshed SOUTHWEST DELTA 39 TIDAL FLAT SEDIMENTATION: INSIGHTS FROM THE DUTCH COASTLINE Brandee Carlson SOUTHWEST DELTA 45 A TALE OF TWO DELTAS - EASTERN SCHELDT, NETHERLANDS AND SAN LUIS PASS, TEXAS, USA Katherine A. Anarde ROTTERDAM PORT 51 UNDERSTANDING VULNERABILITY AND ACCEPTABLE FLOOD RISK TO STORAGE TANKS Sabarethinam Kameshwar ROTTERDAM CITY 59 SPATIAL EVALUATING THE NETWORK OF PLANS AND FLOOD VULNERABILITY IN FEIJENOORD Matthew L. Malecha ROTTERDAM CITY 69 NATURE BASED SOLUTIONS FOR URBAN FLOOD PROOFING Randall Andress LAKE IJSSEL REGION 75 THE AFSLUITDIJK - ALTERNATIVE DESIGN FY2100 Rahmatullah Faizi NETHERLANDS 83 STATISTICAL ANALYSIS OF EXTREME COASTAL WATER LEVELS IN THE NETHERLANDS Fatimata Diop NETHERLANDS 91 MATHEMATICAL MODELLING OF MORPHOLOGICAL RIVER PROCESSES TO PREDICT BANK FAILURE Joshua Brown NETHERLANDS 103 DEVELOPMENT OF A HAZARD INDEX FOR WINTER STORMS Benjamin Bass

6 7 2017 NSF-PIRE THREE 111 STUDENT RESEARCH REPORTS 2017 student group at field visit location CASE # 1 113 LAKE IJSSEL REGION: NEW TOWNS COPING WITH FLOOD RISK Maeslant Barrier, LAKE IJSSEL REGION 115 A REVIEW OF ADAPTIVE CAPACITY OF NEW TOWNS TO FLOOD RISK Rotterdam, June 05, Kayode Atoba 2016. LAKE IJSSEL REGION 123 QUANTIFYING IMPACTS OF URBANIZATION ON FLOOD RISK UNDER CONTRASTING MANAGEMENT STRATEGIES Avantika Gori LAKE IJSSEL REGION 135 FLOOD RISK COMMUNICATION PLANS OF ALMERE AND IJBURG Sarah Reinert LAKE IJSSEL REGION 141 PHYSICAL AND SOCIAL VULNERABILITY OF SOCIAL HOUSING AND PERIODIC MAINTENANCE OF HOUSING ASSOCIATIONS Ki Jin Seong LAKE IJSSEL REGION 151 QUANTIFYING IMPACTS OF URBANIZATION ON FLOOD RISK UNDER CONTRASTING MANAGEMENT STRATEGIES Alaina Parker LAKE IJSSEL REGION 163 STRATEGIES FOR PUMPING STATIONS IN ALMERE AND NEW ORLEANS Dominic Herkes

CASE # 2 169 ROTTERDAM PORT: VULNERABLE INFRASTRUCTURE ROTTERDAM PORT 171 IMPACTS OF WATER DRIVEN DEBRIS IMPACTS ON ABOVE GROUND STORAGE TANKS Carl Bernier ROTTERDAM PORT 179 VULNERABILITY STUDY AND COMPARISON OF TRANSPORTATION INFRASTRUCTURE Lei Bu ROTTERDAM PORT 185 SOCIAL MIXING AND FLOOD VULNERABILITY: A COMPARATIVE ANALYSIS BETWEEN HOUSTON AND ROTTERDAM Emily Fucile Sanchez

CASE # 3 191 SAND ENGINE: COASTAL ENGINEERING WITH NATURE SAND ENGINE 195 A NUMERICAL MODELING INVESTIGATION OF SPREADING TIME SCALES FOR A HYPOTHETICAL MEGA-NOURIHSMENT Andrew Whitley SAND ENGINE 203 MULITFUNCTIONALITY OF AN ENGINEERED COASTAL PROTECTION STRUCTURE Deirdra Dittmar SAND ENGINE 211 SEDIMENT VOLUME ESTIMATION FOR A MEGA-NOURIHSMENT ON FOLLET’S ISLAND, TEXAS Connie Do SAND ENGINE 218 SYNERGETIC EFFECT OF PROPAGATING CONGENER SPECIES OF AMMOPHILIA ON EROSION REDUCTION OF DUNES Bella Jeziersky

CASE # 4 225 NIJMEGEN & WAAL RIVER: ROOM FOR THE RIVER: ROOM FOR THE RIVER 227 ASSESSING FLOOD VULNERABILITY AND THE NETWORK OF PLANS IN NIJMEGEN Siyu Yu ROOM FOR THE RIVER 237 A SOCIAL PERSPECTIVE ON THE SUCCESS OF ROOM FOR THE RIVER - THE STORY OF LENT Madison Bennett ROOM FOR THE RIVER 243 ROOM FOR THE RIVER WAAL: COMPARING HOUSTONIAN AND DUTCH LAND USE PLANNING George Barrow

COLOPHON 248

8 9 ONE | EDUCATION, RESEARCH & OUTREACH

10 11 NSF PIRE FRR Program student field visits in the Netherlands, AUTHENTIC LEARNING AND TRANSFORMATIVE EDUCATION discussing with and learning from local experts and stakeholders. EDUCATION Top image: Maeslant Barrier at Rotterdam. Bottom image: Dike Coastal flooding has emerged as one of the most pressing societal problem-solving skills and confidence in their own learning abilities. in Dune construction problems in the U.S. and around the world. However, there has been Discourse is an essential feature of authentic learning environments in Katwijk along the little comprehensive research on the causes, consequences, and policy because debate and collaborative problem solving enable students North Sea coast. implications of reducing flood impacts. As a response, we conduct to view knowledge and information from multiple perspectives. this integrated, binational flood risk reduction research and education Because students regulate this process of learning internally, they program that brings together multiple academic institutions in are encouraged to think, explore, and become more reflective both the Netherlands and the U.S. The program is broad-ranging by practitioners (Duignan, 2012). combining transdisciplinary inquiry with undergraduate and graduate education focusing flood risk reduction. At the same time, the Problem Based Learning (PBL) program is focuses on several local case study sites in both countries. A key application of an authentic learning environment is the use Through this approach, we have experts from multiple disciplines of problem-based learning (PBL) techniques. A greater level of working together to understand and solve common flood problems responsibility, competency, and learning results when an authentic that will undoubtedly lead to transformative findings on how to problem is shared by a team of students, and the goal of the course is reduce the risk and associated adverse impacts of floods. In terms of to solve the problem collectively (Friedman and Deek, 2002; Donnelly, broader impacts, we established a problem-based learning education 2006). A central premise of PBL is linking theoretical knowledge to and outreach program intricately linked to the research components practical application through the use of collaborative groups in which that serves to educate, involve, and train students, local stakeholders, students are responsible for deciding what is to be learned (Allen and other interested parties. et al., 2011). The rationale for instructional strategies that encourage cooperation between learners is that such strategies more closely Authentic learning approximate the real world than traditional didactic approaches The educational component is an integral part of the PIRE Flood Risk (Gallagher and Gallagher, 2013). Research on PBL has indicated that Reduction (FRR) program, where interdisciplinary, binational teams of collaborative groups are associated with higher levels of student students conduct place-based assessments within the 6 case studies. learning and critical reasoning capabilities. PBL provides constant, The primary goal of the program is to create ‘authentic learning iterative practice of a logical, analytical, and scientific approach to environments’ that both support and benefit from the research problem solving that yields effective reasoning skills. components. Case studies Traditional classroom environments have been criticized for not A major element of authentic learning and PBL is the use of providing essential contextual features that enable students to collaborative groups to explore, analyze, and solve problems understand and apply information (Schmidt, 1993). As a response to presented in case form (Cockrell et al., 2000). Three main these criticisms, a new form of education is gaining prominence called characteristics of case studies make them an ideal strategy to ‘authentic learning’ (Nicaise et al., 2000). Authentic learning involves facilitate authentic learning. First, a case is based on a real situation or learning based on real-world problems that are closely related to event forcing students to think through problems they may encounter a specific field of study (Herrington et al., 2014). This approach in the work place. Second, the case study is developed through to education is grounded in the notion that learning occurs when careful research and study. Third, and most important, a case provides students are given problems and situations that represent genuine learning opportunities at various levels for those involved in the complexity. Students are also better prepared to solve real-world construction of the case as well as for those who may interact with problems once they leave the classroom environment and enter the case (Wallace, 2001). In general, a well-crafted case anticipates professional arenas. scenarios that a learner might eventually face in situations that do not allow time for careful deliberation (Coppola, 1996). Unlike past educational approaches where students are told what they need to know, authentic learning occurs through inquiry PBL is unique because of its connection to place and the analysis of and discovery. Learning in this case is presented as an iterative case studies. Place-based education uses the principles of authentic 12 process of discovery around an authentic task so that students gain learning and applies them to a particular spatial setting such as a 13 NSF PIRE FRR floodplain or vulnerable community. Collaborative learning is geared partners include two other Historically Black institutions and one Program student to the local context where students can experience a specific Hispanic Serving Institution, giving this program access to a large field visits in the problem first hand, how it affects their own lives, and the actions pool of high-performing underrepresented students who already are Netherlands, needed to address the problem. In these situations, students have the involved in relevant studies and work. Generally, undergraduate and discussing with opportunity to produce rather than consume, teachers act as guides graduate students within the four U.S. campuses are recruited through and learning from instead of solely instructors, and groups work together to develop a postings, information sessions, in-class announcements, email listserv, local experts and set of strategies for addressing an actual problem (Smith, 2002). For and online materials. Prospective participants are asked submit an stakeholders. example, research closely related to place-based education found application requiring a description of how the Netherlands site visit Top image left: that student involvement in authentic and meaningful work enhanced will fit into their program of study and research focus, academic design workshop student engagement and performance (Yadav et al., 2011; Warren et transcripts, a resume, and one recommendation letter. ar Hondsbossche al, 2012). and Pettemer Sea Outlook Defense. Study Site Visits Students receive credit for their research experience and we Top image right: Each case study site acts as a focal point for place-based assessments anticipate that eventually it will be offered as a new course on Professor Jonkman and the development of authentic learning environments. Graduate multiple campuses. This approach creates genuine learning explaingn Dutch and undergraduate students are recruited from all participating environments where students from multiple disciplines, countries, and flood riks strategies campuses, placed in interdisciplinary teams, guided by project faculty cultures can work together on flood-related problems. The program at the TU Delft (both from the U.S. and from The Netherlands), and travel to one of thus provides a synergy not possible through normal education exposition space. the six research sites to conduct an intensive case study analysis. or research channels, and will undoubtedly lead to more effective Bottom image: The FRR program entails one study field trip in The Netherlands training of students and management solutions for developing field visit to per year (in summer) comprised of approximately 15 students per sustainable and resilient coastal communities over the long term. We Futureland and visit. Each of the four U.S.-based institutions nominates students also work with Dutch partners to leverage and expand their on-line Maasvlakte 2, through a standard application process. Students are then assigned course on ‘Building with Nature’. We are already in discussions about the Green Port a particular study site based on their interests and field of study. jointly offering online and digital education alternatives (including construction. Selected students work on the TU Delft campus based on existing Massive Open Online Courses MOOC’s) in both countries that would at Rotterdam. agreements, where they are able to interact with Dutch students directly draw from data and research findings generated through the Group poses at studying flood risk reduction. Participants are given a per diem for FRR program. new dunes and food, and transportation will be provided to each study site on a daily beach constructed basis. Each site visit lasts two weeks week. Language barriers are not for recreational an issue as the Dutch speak and teach in English. purposes in the port area. In addition to offering experiences to U.S.-based students (both graduate and undergraduate), we continue to work with TU Delft to host Dutch students (up to 10 per year) conducting research among the three Galveston Bay PBL study sites. Non-paid lodging and meals is arranged on campus or a site on Galveston Island, TX.

Overall, the student teams leverage data and findings produced by the research components of the program to work on real-world problems related to coastal flooding in both countries. Final reports, assessments, and collected data then feed back into and support the ongoing research efforts of the participating faculty. In this way, students learn by actively participating in the research process and each new cohort benefits from the knowledge produced by their predecessors.

Student recruitment The program places particular emphasis is on actively recruiting students from underrepresented groups to participate in the program. Jackson State University (a Historically Black University) leads these recruiting efforts through their role as lead partner for the Education and Technology Transition functions of the recently-established Department of Homeland Security’s Coastal Resilience Center of 14 Excellence. In addition to Jackson State, the Center’s education 15 Figure 1. Workshop brochure NWO Program – CoCoChannel Workshop Participants of international & NSF-PIRE Program Ad van der Spek – TU Delft multidisciplinary Anne van Loenen – TU Delft INTERNATIONAL MULTIDISCIPLINARY DESIGN WORKSHOPS Badreyah Almarshed – Texas A&M University design workshop Bee (Baukje) Kothuis – TU Delft Benjamin Bass – Rice University 2016. Bertien Broekhans – TU Delft ‘TEXAS MEETS TEXEL’ Brandee Carlson - Rice University Dano Roelvink – UNESCO-IHE Design Workshop Fatima Diop – Jackson State University EDUCATION Felix Knipschild – TU Delft Felix van Zoest – TU Delft Floortje d’Hont – TU Delft Graciella Nava Guerero – TU Delft Hao Wang – UNESCO-IHE Collaborative design workshops are also important components of the Ilse Caminada – TU Delft FRR program. The 2016 and 2017 workshops were multidisciplinary Ilze Plomp van der Sar – TU Delft Jan Mulder – Deltares events within two academic research programs (Dutch NWO research Jens Figlus – Texas A&M Univeristy Jill Slinger – TU Delft program ‘CoCoChannel’ and US NSF-PIRE program ‘Coastal Flood Joshua Brown – Jackson State University Risk Reduction’) and the water authority Hoogheemraadschap Kathelijne Wijnberg – UT Twente Katherine Anarde - Rice University Hollands Noorder Kwartier (HHNK) focusing on innovative flood Leonie Akerman – TU Delft Marjan Duiveman – HHNK Water Authority protection projects on the Dutch coast. In 2016, the NSF-PIRE FRR Marloes Wittebrood – TU Delft - HHNK student group collaborated with ten students representing multiple Matthew Malecha – Texas A&M University Mick van der Wegen – UNESCO-IHE disciplines from TU Delft on the case Texel, an eroding barrier island in Nikki Brand – TU Delft the north of the Netherlands (see Figure 1 for the brochure). Peter Herman – Deltares Petra Goessen – HHNK Water Authority In 2017, the design workshop focused on the case Hondsbossche Philippe Galofornisilva – TU Delft and Pettemer Sea Defense, a mega-nourishment project including a Rahmatullah Faizi – Jackson State University Randall Andress – Texas A&M University multifunctional flood defense system (see Figure 2 next page for the Renate Klaassen – TU Delft st Date: May 31 , 2016 Sabarethina Kameschwar – Rice University brochure). Twelve students from two Dutch universities (TU Delft and Time: 09:00 – 17:30 hrs Yoonjeong Lee – Texas A&M University VU University) collaborated with the U.S. students on location in a Place: TU Delft Science Center beach pavilion in Petten.

The design workshops included active consultation with local stakeholders and local experts. One of the learning points from the 2016 design-workshop was that on-site execution provides a more Time schedule & Program conducive learning environment (Figure 3 next page). 08:45 Registration

09:00 Step 1. Introduction workshop participants & case The NWO research program CoCoChannel (‘Co-designing Coasts using Natural Channel-shoal dynamics’) aims at implementation of 09:10 Step 2. Case & Systems introduction by local & specific field experts Ad van der Spek – Deltares the concept Building-with-Nature for coastal flood protection at the Kathelijne Wijnberg – UT Twente Marjan Duiveman – HHNK Water Authority barrier island Texel in the North of The Netherlands. To implement Peter Herman – Deltares such an innovative concept requires early interaction with the

10:30 Coffee break stakeholder community, not only for obtaining their support but also for deriving a more optimal design of the intervention. Therefor, in 11:00 Step 3. Challenges & Stakeholders - Exploration of problem situation & creating the design space both multidisciplinary design workshops conducted with the U.S.

12:30 Step 4: Introduction of Design session and Dutch students, direct interactions with local stakeholders and ! intro design challenges various experts as well as systems understanding in the process of ! intro design roles co-designing nature-based interventions for the eventual design, were 13:00 Step 5. Design session (& Lunch break!) Experts have ‘box-office’ function (in Dutch we call this ‘loket-functie’): important part of the authentic learning experience. the place where one can go and ask for additional information.

15:00 Tea break The TU Delft’s Center of Expertise and Education supports the

15:20 Step 6. Presentations of designs workshops to further enhance the learning experience. The students Each group presents their design for expert jury learn about different roles experts can take in STEM-projects and

16:00 Step 7. Reflecting on design roles work environments. They are informed about four differnt roles and do a self-assessment to find out which role is most comfortable to 16:30 Step 8. Reflecting on designs Feedback from expert jury them. During the workshop, they practice various roles and experience

17:00 Drinks and snacks the culturally different interpretation of these roles with Dutch and U.S. participants. Finally, they discuss their experience by means of a 16 worksheet that is filled in during the workshop (Figure 4 next page). 17 Figure 2. Figure 3. Workshop brochure The NSF PIRE Coastal Flood Risk Reduction Program News coverage is a 5 year collaborative research and eduction program by three US universities of international – Texas A&M University (Galveston and College Station campuses), Rice of bi-national multidisciplinary University, and Jackson State University – and TU Delft in The Netherlands. NSF-PIRE Program multidisciplinary his year stdents are part of the place based feld research tea and design workshop travel to the Netherlands from May 31 to June 15, 2017 to study issues related Coastal Flood Risk Reduction design workshop to food itigation his international opportnity ill enable both gradate 2017. and undergraduate students to enhance and extend their current educational 2017. A news item on and research experience by participating in group research activities and local tv was also part interacting ith food experts in the etherlands Stdents fro dierse disciplines, including: engineering, planning, economics, hydrology, biology, of the coverage. architectre and coptational hydralics ho are interested in food ris reduction are encouraged to apply. Students will work on one of four case ‘TEXAS MEETS HPZ’ studies in the Netherlands to their choice. This program provides a unique opportunity to participate in interdisciplinary research with studentsfrom diverse backgrounds and academic levels. Multidisciplinary Design Workshop

ne of the actiities in the etherlands feld research is a ltidisciplinary A Building-with-Nature Living Lab Design workshop, a full day program on location where Dutch & US students of multidisciplinary backgrounds participate to design integrated solutions for coastal food ris redction ere happy to annonce that in stdents of both TU Delft and VU Amsterdam will be part of the Dutch representation to collaborate with the US student team.

Find further information on the NSF-PIRE Coastal Flood Risk Reduction Program: ‘Integrated, multi-scale approaches for understanding how to reduce vulnerability to damaging events’: www.tamug.edu/ctbs/PIRE

2017 Netherlands case studies: www.tamug.edu/ctbs/PIRE/application.html

Follow the team on Facebook: www.facebook.com/Coastal-Flood-Risk-Reduction-Program-125485164469471/

Contacts: Bee Kothuis - [email protected] Yoon Lee - [email protected]

Date: June 09, 2017 Time: 10:00 – 16:30 hrs Image courtesy - Drawing: STW Perspectief Program NatureCoast - Photo’s: Rijkswaterstaat Beeld bank & Wim ten Brinke Location: Hondsbossche & Pettemer Zeewering; @ Zee&Zo

Day Program ‘TX meets HPZ’ A Building-with-Nature Living Lab

07:45 Leave from Student hotel for TU Delft: pick-up by tour bus 08:15 Arrival & Departure TU Delft - Zuidplantsoen– pick up TU Delft students [08:15 Departure Amsterdam – pick up VU students by Bee] 08:55 Arrival & departure P&R Hoofddorp – bus pick up Bee & VU students 09.50 Arrival Petten - Beach Pavillion Zee&Zo

Multidisciplinary Design workshop & Design Engineer roles

10:00 Welcome & start workshop

Step 1. Systems , local context & design roles introduction by local & specifc feld experts Step 2. Characterizing the social & biophysical environment: Stakeholders & Systems BUILDING WITH NATURE 1. Field experts 2. Stakeholder and Challenges 3. Design Challenge 4. Motivations and Design Requirements 5. Design Session 6. Presentations 7. Reflection 8. Expert reflection Exploration of problem situation & creating the design space Workshop participants Figure 4. LIVING LAB Step 3: Design Assignment Step 4: Design roles: Motivation & requirements Kayode Atoba (TAMUG) - Floorje d’Hondt (TUD) Worksheet for 4. Motivations - Stakeholders and challenges Design requirements 20 min 5. Design Session 90 min 6. Presentations - 30 min George Barrow (Rice) Lise Jansen (TUD) You prepared a presentation of 5 minutes. Make use of a flip-over sheet or Step 5: Lunch & Design session (in teams) Madison Bennett (TAMU) Bella Jeziersky (TAMUG) practising with anything else you would like to use. An integral design for food risk reduction @ Petten Phil Berke (TAMU) Yoon Lee (TAMUG) different expert roles Contextual Carl Bernier (Rice) Feihong Liu (TUD) Engineer Step 6: Presentations of designs Anneroos Brussee (TUD) Renate Klaassen (TUD) 7. Reflection - 30 min in STEM-projects and After the final presentations, rate the design requirements that you Example Step 7: Design roles: Refelcting on design & design process have written down in step 3. You will get to fill out a form from the -2 -1 +1 +2 Lei Bu (JSU) Bee Kothuis (TUD) design role that is predetermined. Use a so-called Harris Profile. You Refection on design criteria rate your final Building with Nature design with the design requirements Danielle Ceulemans (TUD) Joke Kruit (Dorpsraad) work environments. with a value of: -2, -1, +1, +2. See the example on the right on how you can fill out the Harris profile. Step 8: Refecting on designs by experts & a pie for the best design! System Anais Couasnon (VU) Jos Muller (TUD) Indicate why this requirement would fit/does not fit the final solution. Integrator Deidra Dittmar (TAMUG) Natasja Oostrum (TUD) Reflect on whether or not you think the requirements meets the engineering role, and write down why you think that. 16:30 Closing & for who’s interested: short walk to dunes, Connie Do (Rice) Alaina Parker (TAMU) dike covered by dune, North Sea beach Laura van der Doef (TUD) Sarah Reinert (TAMUG) 1. Name: 2. Engineering Role (That has been assigned Bruce Ebersole (JSU) Kijin Seong (TAMU) to you): 3. Did you make use of the design If you exclude it, how role perspective in your design? would you change the Do you believe the Jens Figlus (TAMUG) Jill Slinger (TUD) Why did you design and implement it requirement matches Write down design include/exclude the if you have all the the engineering role? Specialist Fill out: requirements from -2 -1 +1 +2 requirement? resources? WHY? 17:00 Departure from Petten Emily Fucile-Sanchez (TAMUG) Carlijn van der Sluijs (VU) step 3: 17:45 Arrival P&R Hoofddorp, drop Bee & VU Students – Petra Goessen (HHNK) Sierd de Vries (TUD) Bee drive to VU & drop off Maartje Godfroy (TUD) Andrew Whitley (TAMUG) 18:30 Arrival TU Delft, drop TU Students Design process Avi Gori (Rice) Siyu Yu (TAMU) Write down your design process and WHY you did this step. 19:00 Arrival Student Hotel Rotterdam Dominic Herkes (Rice) Front End Innovator 18 19 Images by students, expressing their experiences in The Netherlands during STUDENTS’ TESTIMONIALS the field visits.

EDUCATION

“This research trip helped me visually understand the interaction “I was provided a world class field experience in terms of between these structures and the built/human environment. I understanding flood risk control strategies and mitigation. The have gained tremendous leadership experience in mentoring both design workshop at Petten was so effective in enhancing teamwork, undergraduate and graduate students in achieving a successful leadership skills and multidisciplinary knowledge on flood research experience.” management strategies.” – Kayode Atoba – Bella Jezierski

“The opportunity to have discussions with professors from a wide “I was taught how to formulate research questions and how to go variety of disciplines and universities also helped me figure out my about answering them. I was able to make lasting friendships with the academic and professional future.” participants of the trip and felt honored to be able to work and travel – George Barrow with such a fun, intelligent, and wonderful group of people.” – Dominic Herkes “The most interesting part was the four different field trips which allowed me to learn more about engineering concepts that are less “The NSF-PIRE program was a great stimulus that caused me to think common from a North American point of view such as engineering/ about how a community can have a robust flood reduction system building with nature and multi-functional flood defenses. I came back within multiple layers of strategies and how the system can reduce to the US with new insights, ideas, and methods for my research and residential displacement caused by disasters.” thesis. It also allowed me to build a network of contacts that will be – Kijin Seong helpful for my doctoral studies and my future research career.” – Carl Bernier “The NSF PIRE Coastal Flood Risk Reduction Program provides a unique opportunity to gain experience from not only multidisciplinary “Being an undergraduate Offshore and Coastal Systems Engineering integration but also cross-cultural collaboration.” student, this trip has brought new ideas to my mind that I plan to – Siyu Yu incorporate into future projects.” – Deidra Dittmar

“The program’s immersive structure involving site visits and expert interviews helped me gain a deeper appreciation for the research we were conducting and its implications for flood risk mitigation strategies in the upper Texas coast. I highly value the program’s focus on engagement and interaction.” – Connie Do

“It gave me the chance to work in an interdisciplinary team, where I was exposed to many aspects of flood risk including social vulnerability, landscape planning, and risk communication. This program has pushed me to expand my research interests in order to foster collaboration with different fields and different universities.” – Avantika Gori

“This trip helped my rediscover my love for learning. I have gained skills that I will keep with me for a lifetime and friends that I hope to collaborate with often.” 20 – Sarah Reinert 21 INTEGRATED, MULTI-SCALE APPROACHES FOR UNDERSTANDING HOW TO REDUCE VULNERABILITY TO DAMAGING EVENTS

RESEARCH APPROACH

Within each study region in the U.S. and the Netherlands, six sub-case It is important to note that these sub-case studies are not being studies were chosen covering both surge-based and precipitation- conducted independently, but instead researchers and students driven flood problems (see Figure 2 below). Each case provides a use these sites to form a network for sharing data, methods, and target area for interdisciplinary research and education on physical results across different types of flood hazards. Cross-fertilization flood risk, socioeconomic characteristics, built environment patterns, of knowledge and data is essential to forming a comprehensive and mitigation techniques. The effectiveness of both structural understanding of sustainable flood risk reduction in coastal regions. and non-structural strategies are being investigated, leading to a better understanding of when to pursue avoidance and resistance Within case studies, various topics are investigated using multiple approaches for mitigating adverse impacts from flood events. scientific methods, including:

In Texas, we focus on the Houston-Galveston region surrounding - Multi-scale coastal risk assessments and flood model development. Galveston Bay. Galveston Island, which was struck by Hurricane Ike - Integrated ecological planning and engineering solutions for in 2008 serves as the storm-surge focal area. This island has a long mitigation and planning. history of storm impacts, a diversity of development patterns and - Economic and social impact considerations, such as cost-benefits socioeconomic characteristics, making it an ideal location to apply our of different mitigation approaches and multifunctional defenses to research framework. Inland flooding and rapid urbanization is being flooding threats. analyzed within the Clear Lake/NASA area just south of Houston. - Coordinating networks of open space, ecological restoration, This study site, consisting mostly of residential and commercial development for flood mitigation. development, also provides an ideal test-bed for examining the - The implications of climate change on flood risk, socioeconomic, intersection between rainfall and surge-based inundation. Finally, and reduction of impacts. the Houston Ship Channel provides a living laboratory to better - Effects of different development patterns and land use change understand flood issues in a heavily industrialized and developed area scenarios on flood vulnerability. that has national economic importance. - Recovery versus protection-based approaches to mitigation and planning. In the Netherlands, we chose three complementary study sites that - Understanding and managing the spatial intersection of salt and can be compared to those in the U.S. Storm surge and river flow freshwater flooding. issues are being examined in the Rotterdam – Rijnmond area, the first study site. Like Houston, Rotterdam is a large urban area; it Each case study follows an integrated layering approach, where is situated at the mouth of the Rhine and Meuse rivers containing physical flood risk modeling acts as the foundation for every analysis. a major international shipping port mostly below sea level. Underpinning each research theme and case study is the development Urban development, port development, flood defence strategies, of a major data repository that integrates engineering models, environmental and energy policy are strongly interwoven with each socioeconomic characteristics, land use and built environment, policy other, making this an ideal case study. The second study site, the and perceptions at multiple spatial scales (from parcel to large Western Scheldt, is an intertidal area vulnerable to storm surge and watershed). These data are stored on a shared server network and riverine flooding. While a critical navigational channel to Antwerp, this disseminated through a web-based coastal atlas. The assemblage, area is experiencing declining development, making it an interesting sharing, and visualization of data drive empirical inquiry as well as case for examining the role of restoring natural functions for flood provide an explicit link to education and outreach components of mitigation. The third Netherlands case study site focuses on the the program. It is important to note that the research could not be IJsselmeer/Lake Ijssel area. This is a dammed freshwater system accomplished without sharing data, modeling techniques/software, comprised mostly of residential and agricultural land uses. The area facilities, and experiences across all partner institutions. is being targeted for studying rainfall and riverine flooding, and investigating how development buffers and natural functions can 22 effectively mitigation property loss. 23 Research Framework AN INTEGRATED RESEARCH FRAMEWORK

RESEARCH APPROACH

An integrated research framework (Figure 1) based on the above ENVIRONMENTAL/PHYSICAL literature review provides a basis for joint inquiry and an overall conceptual structure for the FRR program. Three issue domains: - Surge models Environmental/Physical, Built, and Socioeconomic interact to form - Hydraulic models a fourth system we call Flood Risk Reduction. Inquiry under the - Coastal systems Environmental/Physical domain will help understand the baseline - Sediment transport conditions and boundaries for each coastal case study and will include: storm surge models, hydraulic models, sediment transport, and the overall erosion dynamics of coastal systems.

Boundary Conditions This research helps identify the boundary conditions for the built, social, and economic systems in place. Investigation within the Socioeconomic issue domain consists of direct and indirect

Impacts economic analyses, losses avoided studies, and cost-benefit analysis. Understanding the degree to which communities are socially vulnerable to flooding is also an import line of research. Social and economic systems also impact environmental and physical systems

Boundary ConditionsImpacts FLOOD RISK REDUCTION via population growth, a larger workforce, etc.

- Resistance / Avoidance Finally, inquiry taking place within the Built Environment issue domain - Strcutural / Non-structural focuses on how land use change analysis, development patterns, and public infrastructure contribute to flood risk and associated losses. Development design and visualization is also an important aspect, as it helps incorporate aesthetics and specific development configurations into the research. Alteration of the coastal landscape BUILT ENVIRONMENT SOCIO-ECONOMIC through development also impacts the Environmental/Physical and Socioeconomic domains through the spread of impervious surfaces, - Economic analysis alteration of naturally occurring wetlands, etc. - Land use change : direct/indirect - Development patterns - Losses avoided Interactive inquiry across all three issue domains has led to various - Design/Visualization - Cost-benefit analysis Flood Risk Reduction solutions. This final domain involves the - Social vulnerability generation of mitigation techniques specific to each case study, encompassing resistance, avoidance, structural, and non-structural interventions. We are particularly interested in investigating FRR programs that involve a synergistic set of different techniques (i.e. structural and non-structural measures working in concert). This integrated framework will help program participants see beyond their single discipline and work on flood problems in a more comprehensive manner.

24 25 Partner Institutions and Project Participants THE FLOOD RISK REDUCTION PARTNERSHIP

Department Position/Rank Expertise RESEARCH APPROACH Texas A&M at Galveston

Sam Brody Marine Sciences/ Urban Planning Professor, Director of Institute for Planning, built environment, spatial analysis The FRR program consists of 5 participating institutions and 20 traveling to the Netherlands, a Dutch-funded workshop held in TX, Sustainable Coastal Communities researchers supervising dozens of students. Each institution and and the signing of an MOU between Texas A&M University and Delft William Merrell Marine Sciences Professor Coastal barriers, wave dynamics faculty member offers a unique skill-set associated with flood risk University’s Faculty of Civil Engineering and Geosciences establishing Wesley Highfield Marine Sciences Assistant Professor Spatial analysis, economic impact assessment modeling and management. a long-term cooperative program of academic and scientific exchange Meri Dalvasheridze Marine Sciences Assistant Professor Hazard economics on coastal flood risk reduction. As of 2016, a second Dutch university, Jens Figlus Coastal Engineering Assistant Professor Sediment transport, dune design As shown in Table 1, each partner institution has one or more senior the VU University Amsterdam, started collaborating with the faculty members supported by multiple junior and early career partnership by means of the Institute for Environmental Studies (IVM), researchers. The synergy created by working together on place- the oldest multidisciplinary environmental research institute in the Texas A&M at College Station based case studies provides a comprehensive understanding of how Netherlands. to reduce coastal flood impacts. All of the participants have been Phillip Berke Landscape Arch. & Urban Planning Professor Coastal planning, social vulnerability working together on the binational partnership from its inception, Since the partnerships’ inceptions, over 35 students and 12 faculty Galen Newman Landscape Arch. & Urban Planning Assistant Professor Visualization, landscape design established dependable lines of communication and information members from the Netherlands have spent time working on the Texas Eric Bardenhagen Landscape Arch. & Urban Planning Assistant Professor Landscape planning sharing, and are committed to collaborating around the issue of flood A&M Galveston campus; in turn, 9 faculty and 27 students from the risk reduction in the future. U.S. have been hosted by Delft University (which has invested over 130,000 Euros over the past years from internal grants). In 2015, Jackson State University On the U.S. side, Texas A&M, Galveston campus is the lead university, Delft University has successfully applied for a grant by NWO, the with participating faculty and students from the Institute for Netherlands NSF equivalent, to conduct research on implementation Robert Whalin Civil/Environmental Engineering Professor Coastal engineering, wave dynamics Sustainable Coastal Communities and the Center for Texas Beaches of new risk standards in the flood protection, involving the Houston Thomas Richardson Civil/Environmental Engineering Deputy Director, Hazards Center Coastal and hydraulics engineering and Shores. Galveston’s unique position on the coast provides a Galveston Bay Area as one of it’s case studies. Currently, Delft critical venue for hosting other institutions and a launching point University and VU University partners work on a second, major for case study investigations. Faculty in the Hazard Reduction and application to the Netherlands NWO, to support further international Rice University Recovery Center from Texas A&M University at College Station also partnership on Flood Risk Reduction. plays a vital role, particularly in the fields of landscape architecture Phillip Bedient Civil/Environmental Engineering Professor, Director of SSPEED Center Hydraulic engineering and coastal planning. Core team members from Jackson State Jamie Padgett Civil/Environmental Engineering Associate Professor Critical infrastructure and hazards University, a Historically Black College, contribute extensive expertise on surge modeling and wave dynamics. From an engineering perspective, several faculty from Rice University’s Civil and Delft University Environmental Engineering Department and the SSPEED Center work on issues related to hydraulic modeling, structural mitigation, and Bas Jonkman Hydraulic Engineering Professor, Director of Delft Flood Risk Flood risk assessment, flood defenses critical infrastructure, particularly as they relate to precipitation-based

Center flood events. VU Amsterdam Han Meyer Urban Design Professor Urban Design Anne Loes Nillesen Delta Interventions studio Researcher Landscape design On the Netherlands side of the program, Delft University is the Baukje Kothuis Multi-Actor Systems Post-doctoral Researcher Multifunctional flood defenses lead institution, with participants from numerous disciplines, which Environmental Jill Slinger Technology, Policy, Management Associate Professor Flood policy and governance had already been working internally and with U.S. partners before planning this program started. As shown in Table 1, multiple disciplines participate from within Delft University participate, including policy and management, architecture, and planning/urbanism. Each faculty synergizes with an U.S.-based counterpart in a specific discipline.

The NSF PIRE program represents the evolution of a partnership with Delft University established in 2012 on flood risk reduction strategies in populated coastal areas. This informal collaboration has included 26 an NSF-funded colloquium involving U.S.-based faculty and students 27 Figure 1. Education, Information Dissemination, and INFORMATION DISSEMINATION Outreach Framework

OUTREACH

Another major component of the FRRP is the collection, storage, importantly, users without the technical capabilities and resources and dissemination of both primary and secondary data related to to examine spatial data can still view, interact with, and analyze coastal flood issues. These data are hosted on a server network information related to flood risk and the reduction of future impacts. spanning multiple institutions so that information can be downloaded by participating students and faculty. Each participating institution In sum, our education and outreach plan for the FRR program is will establish a “data sharing node,” which consists of one or several carefully constructed to connect research outputs - to student and workstations that will be directly linked to the FRR program’s central faculty researchers - to interested stakeholders and the general data server. public via multiple communication venues. Through this approach, we implement a fully integrated, two-directional research and education For example, at Texas A&M, Galveston campus we have launched the program that seeks to reduce the risks and impacts of flooding in Coastal Geospatial Lab, a facility that enables researchers working coastal areas. alone or in small groups (both faculty and students) to directly download and analyze on site any spatial data layer housed on the server. We work on creating similar nodes for every partner institution within the FRR program as a way to create a network for data sharing and offer direct access to the central data server across institutional boundaries (see Figure 1).

Data and information generated by the program must be disseminated beyond formal university settings to those without technical expertise. Critical stakeholders affected by the research results may not be equipped to handle and manipulate large spatial datasets off-line. In response to this issue, we develop a binational web-based Geographic Information System (GIS) covering the six Figure 2: Hurricane study sites as a way to disseminate key data and findings to local Surge Zones communities and interested stakeholders. Adjacent to Galveston Bay We are leveraging the existing Texas Coastal Communities Atlas to with “Spotlight” on develop a customized system covering each designated study site in a Critical Medical both the U.S. and the Netherlands. Users with an Internet connection, Facility including local decision makers and residents in both countries, will be able to visualize and examine flood risks and the effectiveness of various solutions generated by FRRP participants.

Users of this Coastal Flood Atlas system will be able to identify, visualize, and query information on hundreds of ecological, socioeconomic, and geophysical spatial data layers. For example, users of the system are able to see critical facilities in relation to flood risk zones and then identify sites most vulnerable to inundation from coastal flooding. A prototype for Galveston Bay has already been developed (see Figure 2) for the project.

Because this mapping tool will be freely accessible, we expect 28 to reach a broad audience with our study data and results. Most 29 TWO | STUDENT RESEARCH REPORTS 2016 HYDRAULIC INFRASTRUCTURE DESIGN INFRASTRUCTURE HYDRAULIC

30 31 Figure 1 Badreyah F. Almarshed Nourished Rodanthe Beach, NC. HYBRID COASTAL STRUCTURES

SOUTH WEST DELTA - NORTH SEA COAST

Badreyah is a PhD candidate in Ocean Engi- etc. Traditionally, it is divided into two reduce flooding. The design depends mainly neering department at Texas A&M University. categories; on hydrodynamic conditions, which includes - Soft protection such as using beach water depth, water level, tidal currents, nourishment (Figure 1), wave parameters such as height, period and As the urbanization in last decades near the – Hard protection such as using seawall direction, and storm surge. coastal cities is increasing rapidly, the (Figure 2). coastlines of these cities must be protected A recent protection approach that combines The magnitude of wave overtopping depends more efficiently. The beach erosion must be both soft and hard coastal protections on the wave conditions, i.e. significant wave mitigated and controlled, and the urban areas is called hybrid coastal defense system height (Hs) and the peak wave period (Tp), behind the coastline need a defense system (multifunctional structure, e.g. Figure 3). the structure slope, and the height of the Figure 2 to protect it from flooding. This defense system combines the benefits structure. The maximum allowed overtopping Recurved seawall at of traditional systems hence it protects varies depending on the location, local Galveston, TX. Without a defense system, major storm can coastal cities from flooding, at the same time laws, and the design purpose. For example, cause great damages. The flood associated preserve the natural aesthetic of the beaches, in Netherlands the maximum overtopping with the storms created a large potential and provide protection from erosion. allowed is 0.1 to 1.0 l/s/m (Haskoning, 2005). damages on the environment, economy, and The design of the storm surge height increased the risk of life losses dramatically. A simple definition of the hybrid defense depends mainly on the storm intensity, wind Both The Houston-Galveston Metropolitan system is that a hard coastal structure, such stresses, the atmospheric pressure reduction area and The New Orleans metropolitan area as a dike, covered by a sand layer. It provides and the bathymetric changes. have experienced their share of severe storm protection against extreme wave conditions impacts. and flood problems, while fulfill secondary Although hybrid coastal structures have functions such as offering through-passage already designed and implanted at different On September 13th 2008, Hurricane Ike for pedestrians and vehicles, enabling places throughout the world, a detailed made landfall on Galveston Island with a recreation and providing spaces for design guideline is still missing. maximum surge of 4.5 m (Stoeten, 2013). agriculture activities (Voorendt, 2012). The This report presents next examples of the Hurricane Ike resulted in an estimated $29.4 purpose of the innovative hybrid defense hybrid coastal protection systems, their billion dollars in damage (Perry et al. 2008). structures is to improve storm protection benefits, their design, and then a summary Hurricane Katrina is another paradigm of the level and at the same time avoid enormous and discussion. devastating disasters that hit the Gulf Coast. social costs and uncompromised spatial The estimates of the monetary damage due solutions. Examples of the hybrid coastal protection to Hurricane Katrina is almost $100 billion systems or more, making it the costliest natural The basic design concept of the multifunction In many parts of the world, traditional coastal Figure 3 disaster in U.S. history (Tornqvist 2007). The defense system is building a flood defense defense systems are adapted to satisfy Cross-section of a major losses that were associated with such structure, which is temporarily used by environmental consideration, landscaping multifunctional 10x devastated storms trigger the international another function, without any adjustments to issues, and tourism needs. Recently hybrid stronger dike: in research institutions and the Government its basic structure (Voorendt, 2012). There is protection systems substitute traditional dark grey profile of agencies to improve the coastal defense not much experimental data published on the defense systems. Hybrid coastal structures a mono functional system of the coastal areas. performance of hybrid coastal structure, and provide protection against flooding and river dike, in light- the design guidelines of the hybrid structure wave actions, and at the same time, they grey a 10x stronger Coastal protection and beach erosion control system have not completely established preserve the natural aesthetic of the beaches dike and zone for requires intensive studies and clear and yet. A significant change in the way that the and provide protection from erosion. The multi-functional use. detailed design criterion to consider all the hybrid coastal structures are designed should Netherlands is one of the countries that (Source: Tromp et al. aspects that may affect the environment, be developed with the emphasis on the widely adopt the hybrid defense systems. 32 2012 [4]) beauty of the beaches, marine life, economic, sand layer impacts on wave overtopping to Those systems preserve the land use and can 33 Figure 4a,b,c, be utilized to provide pedestrians walkways, - Dike in Dune This type of structures increase the space The ‘Roof Park’ parking garages, green areas, recreational A dike in dune in Katwijk aan Zee is another for intensive urban use and at the same time Rotterdam (Source: areas, etc. as will be presented next example of a multifunctional flood defense redesign the flood defense into a virtually Tromp et al. 2012 [4]) (Voorendt, 2012). system in The Netherlands. It was built to unbreachable structure. Especially in highly protect the town from high storm surges urbanized areas all over the world where - Dike in Park level which threaten 3000 inhabitants who in traditional coastal structures reinforcement The ‘Dakpark’ (‘Roofpark’) is an elevated park fact lived in an unembanked area (Voorendt would have negative spatial impacts and be on a former railway yard in the Delfshaven 2012). The dike in dunes is constructed an extended and costly process, this concept quarter in Rotterdam. The park is located to retain critical water levels that could is a promising strategy to align spatial on the roof of a new shopping center, which occur on average once in 10,000 years. development with flood risk management includes a parking garage. The park is the The dike has a sand core and is covered by structures. largest green roof in Rotterdam and one basalton blocks on top of a filter layer and of the largest in the Netherlands (Tromp geotextile as shown in Figure 5. Parking Summary and conclusion et al. 2012). The park offers a playground, garage is constructed between the dike Hybrid coastal structures is promising as a communal garden and a Mediterranean in dune and the main boulevard as shown climate adaption measure and therefore all garden with an orangery. The Dakpark is 1000 in Figure 6. This flood defense system not aspects should be explored more in depth m long and 80 m wide. The park is situated 9 only provides protection against high water by a thorough analysis of scientific literature m above street level. The car park has space level also providing parking spaces. Thus, and of experiences in other countries. for approximately 750 cars. The Dakpark is it is considered as a multifunction defense Additionally, the process of establishing combined with a dike, the ‘Delflandse Dijk’, structure. hybrid structure, from initial idea through that is part of dike ring 14, which protects to implementation, should be monitored at the urban area of the Randstad (Tromp et al. - Dike in Boulevard challenging and appropriate pilot locations 2012). Scheveningen is a seaside resort with a long to learn from experiences. This type of sandy beach in south of Netherlands. Hybrid structures optimize the use of limited spaces, Ultimately, a multifunctional structure has structure (Figure 7) consists of hard dike with requires less adjustments, and have higher been designed that accommodates shops, a soft sandy beach and foreshore designed safety standards in addition to flood defense offices, and a parking garage on the ground for coastal protection purposes. The sand in (Van Loon-Steensma & Vellinga, 2014). It is floor and first floor and a park with leisure front of the dike decreases the overtopping necessary to develop design strategies that functions on the rooftop (Figure 4). volumes, thus reducing the dike’s crest height. are able to deal with dissimilar life cycles of On the other hand, the sand dune in front of urban and flood risk management structures. The original dike is not integrated into the the dike provides toe protection for the dike. Figure 7. new structure of the Dakpark building itself Multifunctional flood defense is newly Hybrid structure (Figure 4). Instead the shopping, office Benefits of the hybrid coastal structures developed concept to optimize allocation consists of hard dike and parking complex is situated next to The Hybrid coastal structure should not be of urban space rather than constructing with a soft sandy the old dike and the space in between the considered as a mono-functional, providing stand-alone structures. They are flood beach and foreshore complex and the dike has been filled out by only flood protection, but can be integrated defenses that combine the function of flood in Scheveningen, soil. Meanwhile, the crest height of the dike into everyday life as a sustainable solution. protection with other functions. In addition Netherlands was raised to make it ‘climate-proof’, which The multifunctional flood defense concept to flood protection, multi-functional flood means that a worst-case scenario in terms aims to use the limited space that is still protection fulfils functions like housing, of sea level rise has been taken into account available along the popular waterfront recreation and leisure, commercial buildings, for the design lifetime of the flood defense. by integrating several functions into one ecology, mobility and transport, underground The complex is situated in the outer zone, multifunctional structure. The extra functions infrastructure and is a functional part of the the ‘influence zone’ of the flood defense added can be designed to be of service urban or rural environment, therefore more according to the definition by the Water for various urban functions. In this way, financial benefits can be generated. Board. multifunctional structure can help to reduce the conflicts between urban development A more extensive scientific studies The additional soil layer on top of the dike is requirements and flood alleviation strategies. (theoretical, numerical, and physical) are not considered to contribute to the retaining In general, Hybrid coastal structures provide needed to develop feasible design criteria for height because the Water Board regards the flood protection and maximize the land use. hybrid coastal structures. In general, flood existing profile as the flood defense. This dike It integrates flood protection with functions protective infrastructures have a designed profile has not been adapted to make space like infrastructure, housing, recreation and life cycle of at least 50 to 100 years, while for other functions. The Dakpark therefore is ecological spaces and therefore more urban functions are designed for a life cycle classified as ‘shared use’. financial benefits can be generated. between 20 to 50 years (Voorendt 2012). 34 Also uncertainties, caused by demographic 35 Figure 5. changes and climate change, require flexible References A dike in dune in design concepts. It is necessary to develop Haskoning, ComCoast WP3 State-of-the-Art Katwijk aan Zee, construction methods and design that enable inventory. 2005, CUR RWS. Netherlands. easy replacement or adjustment if necessary, Perry, R., R. Eckels, and B. Newby, Texas with minimal destruction or demolition. Rebounds. 2008, Austin, State of Texas. Stoeten, K., Hurricane Surge Risk Reduction This design guidance can provide the For Galveston Bay. 2013, TU Delft, Delft means for developing different hybrid University of Technology. structure alternatives and assessing the Tornqvist, T., A Dutch geoscience perspective associated costs and benefits. This can be on the Katrina disaster. Netherlands achieved by linking the current state-of- Journal of Geosciences, 2007. 86(3): p. 307. the-art in literature with the knowledge and Tromp, E., et al., Multifunctionele experiences from actual projects, and by Waterkeringen: Onderzoek naar de conducting more studies and numerical and mogelijkheden voor flexibel gebruik van de physical investigations. waterkering. 2012, Deltares. van Loon-Steensma, J.M. and P. Vellinga, As a summary of this this report, the most Robust, multifunctional flood defenses in the significant advantage of hybrid structure Dutch rural riverine area. Natural Hazards and is that it can generate financial, social and Earth System Sciences, 2014. 14(5): p. 1085- environmental benefits. In contrast, traditional 1098. coastal structures strengthening only Voorendt, M., Examples of multifunctional generates financial costs with non-monetary flood defences. Delft University of benefits (i.e., increased flood safety / reduced Technology, 2012. flood risk). By designing hybrid structures, the costs can be partially funded with the revenues from the secondary functions. It is important to note here that further detailed research is needed into the structural and Figure 6. hydraulic engineering aspects in order to Dike in dune parking provide more reliable estimates of the costs garage in Katwijk and benefits hybrid structures. aan Zee, Netherlands.

Acknowledgements This research was supported by NSF-PIRE, TEXAS A&M University, and Delft University of Technology. I would like to express my sincere gratitude to Dr. Samuel Brody, Dr. S.N. (Bas) Jonkman, Dr. B.L.M. (Baukje) Kothuis, Dr. Phil Berke, Dr. Jens Figlus, Dr. Yoon Lee, Ms. Antonia Sebastian and Ms. Sherry Parker to their major efforts and support for the research.

I am also grateful to Dr. H.J. (Henk Jan) Verhagen, Dr. Bas Hofland and Eng. M.Z. (Mark) Voorendt who provided expertise that greatly assisted this research.

Finally, I would like to thank all my fellow colleagues from Texas A&M University, Rice University and Jackson State University. 36 37 Figure 1. Brandee Carlson Tidal flats along the Dutch coast are demarcated with TIDAL FLAT SEDIMENTATION: INSIGHTS FROM THE DUTCH red boxes. The image to the left is COASTLINE an overview map from the seminal van Straaten, 1961 paper, SOUTH WEST DELTA ‘Sedimentation in Tidal Flat Areas’, Brandee is a PhD candidate at Rice University, Dutch tidal flats have been extensively The sediment found in tidal channels, is which focuses on Houston. studied and have contributed to the usually fairly sandy, while the sediment that Dutch tidal flats. knowledge of processes that lead to tidal exits the tidal channels and gullies is generally The image on flat development around the world. This silt and clay (van Straaten, 1961). The amount the right is a satellite Owing to immense natural resources and paper will review Dutch tidal flats and of clay present in tidal flats is more than image of the Dutch socio-economic benefits major contributions made to tidal flat one would expect based on transport coastline. such as shipping goods, nearly half of the sedimentation, followed by a discussion of conditions, but rather than individual clay world’s population lives within 150 km of a prominent sediment transport processes and particles settling on to the flats, aggregates coastline (Syvitski, Vörösmarty, Kettner, & concepts, and will conclude with application of clay called flocs settle (van Straaten, 1961). Green, 2005). However, coastlines have the of this work to the author’s dissertation area Fecal pellets from invertebrates may also ability to rapidly respond to both natural and on the Huanghe (Yellow River) delta tidal contribute to the deposition of clay and mud human perturbations (sea-level rise, flats. (van Straaten, 1961). Because tidal channels Figure 2A. sediment supply reduction, etc.), which and gullies rapidly move across tidal flat Cross-section of means that populations near the coast are Tidal flats in the Netherlands surfaces (owing to little vegetation, Figure 3), typical tidal flat vulnerable to hazards such as coastal flood Tidal flats are widespread along the Dutch it is common to find deposits of sandy layers configuration. risk and land loss. In an attempt to adapt to coastline (van Straaten, 1961, Figure 1). They associated with channel migration topped Throughout a these changes, we must understand are found in the Wadden Sea as well as in with fine muddy layers deposited by tidalcycle, channels coastline behavior with and without human the estuaries in the southwest. In the north, overbank deposition (van Straaten, 1961). in intertidal areas interference. The focus of this paper is to the tidal range is 1.3-2.8 m and in the south Generally, tidal flat deposits decrease in convey flood understand the intertidal regions along the tidal range is up to 4.5 m (van Straaten, thickness landward due to the fact that and ebb flows. coastlines, particularly where sediments 1961). In the Wadden Sea, tidal flats are able channel depths decrease landward and During flood accumulate and promote land aggradation, to build through fine sediment deposition, therefore less lateral sedimentation occurs flows, sediment- known as tidal flats. which is promoted due to protection from (van Straaten, 1961). For Dutch tidal flats, laden water flows waves from the presence of barrier islands several sources of sediment exist, which over the banks Tidal flats are coastal regions between high- (van Straaten, 1961). In the south, the elongate include fluvial sources and the open sea (van of the channels tide and low-tide datums where fine shape of estuaries transverse to the coastline Straaten, 1961). The mud in the open seas is and contributes sediment accumulates. They are generally provides environments protected from wave delivered by multiple rivers, and is carried by to vertical high in biomass and they support complex activity that also promote fine sediment currents toward estuaries (van Straaten, 1961). sedimentation ecosystems from micro-organisms to deposition (van Straaten, 1961). Water is Fine material is also sourced from eroding displayed in migratory birds (Widdows et al., 2004a). conveyed to both the Wadden Sea tidal flats, Pleistocene and Holocene deposits on the Figure 2B. Lateral Tidal flats are usually found in sediment- and tidal flats in the southwest by tidal North Sea (van Straaten, 1961). sedimentation occurs rich environments, particularly where the channels (Figure 2). During high tide, water on tidal flats through typical wave height is much smaller than spills over the banks of the tidal channels, Once deposited, several factors influence the migration the tidal range (C. Friedrichs, n.d.). Channels delivering sediment to the surrounding tidal the strength of the tidal flat deposit. Algal of channels and often incise the flats, and the sedimentary flats. The tidal flats are generally lacking in mats found on tidal flats in the Western gullies, where one dynamics are governed by a multitude of biodiversity, with the exception of diatoms Scheldt can provide stability and induce bank (cut bank) of dynamics at a broad range of temporal and and algae, however these organisms provide sediment trapping on the surface (Widdows, the channels are spatial scales (Mariotti & Fagherazzi, 2012). a relatively large amount of biomass, and lend et al., 2004). Mechanical strengthening can erosional and the to the support of larger fauna such as also occur through wetting/drying cycles opposite bank (point The Dutch coastline exhibits the largest migratory birds, shellfish, and large fish associated with tidal fluctuations, and bar) is a region of unbroken chain of tidal flats in the world, (Widdows, et al., 2004). Large gullies compression due to weight of overlying active sedimentation qualifying the flats in the Wadden Sea as a typically incise the flats (Figure 2-A), and the sediment also acts to decrease porosity and (2-B, van Straaten, UNESCO World Heritage site. More flats are patterns of these gullies change rapidly (van increase cohesion leading to greater strength 38 1961). also found along the southwestern coast. Straaten, 1961). of the sediment deposit (Widdows et al., 39 Figure 3. (right) 2004b). Biota including macrophytes, Despite tidal asymmetries, tidal channels Motivation Gully traversing microphytobenthos, and macrofauna generally have higher suspended The primary objectives of this work are to use tidal flat in the effect tidal flat stability (Widdows et al., concentrations than tidal flats during fair existing literature to develop a framework for Western Scheldt. 2004b) through biological processes, while weather (Ridderinkhof, van der Ham, & modeling tidal flat sedimentation within the Little vegetation is mechanical processes, such as abrasion due van der Lee, 2000), so tidal channels are a 1996 abandoned channel of the Huanghe. In present in this region to rainfall can act too destabilize the surface potential source of sediments for the flat if a order to fulfill these objectives, first-order of the flat, which is and contribute to erosion (Tolhurst, Defew, transport mechanism to the flats is present parameters must be constrained, such as conducive to rapid Perkins, Sharples, & Paterson, 2006). (Mariotti and Fagherazzi, 2012). Water fluxes the actual area that is inundated by tides lateral mobility of the to the flat occur by water diverging from throughout the tidal cycle. To gain insight gully. Photo credit: Sedimentary Processes on tidal flats the channel during flood and converging to into tidal flat inundation and sedimentation Katherine Anarde. Tidal processes are periodic, however, to the channel during ebb (Ralston & Stacey, behaviors, the following questions will be produce net transportation of sediment, such 2005). During calm weather, sediment can addressed: Figure 4. (far right) as what is required for tidal flat accumulation, be resuspended in subtidal channels due 1. What is the tidal range within the Mariotti and asymmetries in flow properties and/or to high velocities of channelized flow, and abandoned channel tidal flat? Fagherazzi, 2012 sediment properties must exist (C. Friedrichs, preferentially advect sediment-laden water 2. What is the extent of inundation by tides channel- spillover n.d.). Tidal asymmetries, which result from landward by tidal currents (Yang et al., 2003). within the abandoned river channel bed? mechanism the distortion of the tidal wave in shallow 3. How much sediment has been deposited water, promote residual sediment transport Mariotti and Fagherazzi, 2012 propose that through tidal flat sedimentation since the loss (Mariotti & Fagherazzi, 2012). because channels have higher velocities and of fluvial input (i.e. how much material has higher shear stresses for sediment transport, accumulated through tidal processes)? Asymmetries can occur as sediment suspended sediment concentrations are properties/behavior (settling lag, scour lag), higher than on the mudflats. This means that Methods: or in water movement (discrepancies in water there is a net flux of sediment from channels The tidal range in the Bohai Sea has been velocity for ebb and flood currents, difference to the flats, rather than the flats to the extensively documented in literature (Gao, in time of flood/ebb slack, etc.) (Friedrich, channels, allowing the tidal flat to aggrade, Zhuang, Chen, & Zhang, 2015), however tidal 2011; van Maren & Winterwerp, 2013). and they term this the channel spillover wave propagation through a channel varies Analytical models suggest that high friction mechanism (Figure 4). This phenomenon in amplitude from the open sea because the environments promote flood dominance, can occur contemporaneously with flow and wave is being forced through a confined area Figure 5. hence net landward transport, while low sediment asymmetries, and it is likely that (“Tide Dynamics,” n.d.). Prior to this study, The headwaters of friction environments, such as tidal flats, all are at play during tidal flat aggradation the tidal range within the 1996 abandoned the Huanghe are in promote ebb dominance, hence net seaward (Mariotti and Fagherazzi, 2012). channel had not been documented. The tidal the Tibetan PLateau. transport (C. T. Friedrichs & Aubrey, 1988). range was recorded by placing HOBO U20L The channel traveses Huanghe (Yellow River) delta tidal flats water level and temperature data loggers northern China, and Furthermore, the phase of tidal constituents Sourced from the Tibetan Plateau, the within the abandoned channel and on the debouches into the can lead to flow asymmetries even without Huanghe traverses northern China and flats surrounding the channel (Figure 7). Bohai Sea, building wave distortion (Hoitink, Hoekstra, & van debouches into the Bohai Sea where it the Huanghe delta. Maren, 2003). When paired with settling lag builds the Huanghe delta (Figure 5). High Water level was recorded for every five and vertical mixing induced by variability of sediment loads in the Huanghe lead to minutes over the course of 22 days. The floc transportation during flood and ebb rapid sedimentation and therefore rapid loggers were placed transversely to the tide, the result is net landward transport delta dynamics. On a decadal timescale, the channel, with one in the tidal channel, on far (Mariotti & Fagherazzi, 2012). Scour lag is Huanghe floods and changes the course of from the channel on the flat (far floodplain), defined as the greater critical shear stress its river, leading to the abandonment of and one in between on the channel and required for mobilizing particles from the bed some delta lobes and the activation of the far floodplain (midfloodplain). Figure 8 compared to the stress required to maintain new delta lobes (Figure 6). Upon the displays the water depth above the pressure particles in suspensions (van Maren & abandonment of a delta lobe, the region that transducers. Winterwerp, 2013). Settling lag is defined as was once a river channel is a low-elevation the period or distance that a particle can scar that is subjected to the tides of the In order to predict what areas are inundated travel when the flow velocity has fallen below Bohai Sea. The semi-diurnal inundation by through a tidal cycle, it is also necessary to the critical shear stress for erosion before tides leads to the evolution of new tidal collect topography data. To fulfill this settling on the bed (van Maren & Winterwerp, flats on the Huanghe delta. This study will requirement, an elevation survey was 2013). Both of these mechanisms commonly focus on a channel abandonment and tidal conducted using a Leica Total Station. lead to the net landward transport of fine flat evolution, with focus on a region that was The survey was started at a known elevation sediment. abandoned in 1996. point, and transects were collected every 40 41 Figure 6. (right) 500m transversely to the channel (Figure References http://doi.org/10.1007/s10452-005-9001-7 Landsat Images of 9-A). Elevations were documented for Friedrichs, C. (n.d.). 3.06 Tidal Flat Van Maren, D. S., & Winterwerp, J. C. (2013). the Huanghe (Yellow the pressure transducer locations, so the Morphodynamics: A Synthesis. The role of flow asymmetry and mud River) delta, China. water level data collected by the pressure Friedrichs, C. T., & Aubrey, D. G. (1988). Non- properties on tidal flat sedimentation. transducers can be translated to an elevation, linear Tidal Distortion in Shallow Wellmixed Continental Shelf Research, 60, S71–S84. Figure 8. (far right) therefore inundation over the abandoned Estuaries: a Synthesis a. Estuarine, Coastal http://doi.org/10.1016/j.csr.2012.07.010 Water depth channel surface can be predicted. Figure and Shelf Science, 27, 521–545. Widdows, J., Blauw, A., Heip, C. H. R., Herman, recorded by 9-A displays a surface interpolated from the Gao, X., Zhuang, W., Chen, C.-T. A., & Zhang, P. M. J., Lucas, C. H., Middelburg, J. pressure transducers elevations collected, and then projects the Y. (2015). Sediment quality of the SW J., Verbeek, H. (2004a). Role of physical and located in the tidal elevation of the high spring tide over the coastal Laizhou Bay, Bohai Sea, China: a biological processes in sediment channel and on surface (9-B) and the mean low tide over comprehensive assessment based on the dynamics of a tidal flat in Westerschelde the surroudning the surface (9-C). The projected inundation analysis of heavy metals. PloS One, 10(3), Estuary, SW Netherlands. Marine Ecology floodplain. surfaces are in good agreement with the e0122190. Progress Series. http://doi.org/10.3354/ extent of fine material cover from tidal flat http://doi.org/10.1371/journal.pone.0122190 meps274041 sedimentation as well as observations from Hoitink, A. J. F., Hoekstra, P., & van Maren, D. Widdows, J., Blauw, A., Heip, C., Herman, P., satellite imagery. S. (2003). Flow asymmetry associated Lucas, C., Middelburg, J., Verbeek, H. Figure 7. (right) with astronomical tides: Implications for the (2004b). Role of physical and biological a tidal channel and The remaining objective of this study is to residual transport of sediment. Journal processes in sediment dynamics of a tidal tidal flat occupy the constrain rates of sedimentation on the of Geophysical Research, 108(C10), 3315. flat in Westerschelde Estuary, SW 1996 abandoned tidal flats. This will be accomplished by http://doi.org/10.1029/2002JC001539 Netherlands. Marine Ecology Progress Series, channel. A red star using collected velocity measurements and Mariotti, G., & Fagherazzi, S. (2012). Channels- 274, 41–56. http://doi.org/10.3354/ marks the location suspended concentration data within the tidal flat sediment exchange: The meps274041 where water level channels to project sediment over the tidal channel spillover mechanism. Journal of Yang, S., Friedrichs, C. T., Shi, Z., Ding, P., Zhu, data logger were flat. Samples were collected on the surface Geophysical Research: Oceans, 117(C3), J., & Zhao, Q. (2003). Morphological deployed within the of the tidal flat to evaluate the size of the n/a-n/a. http://doi.org/10.1029/2011JC007378 Response of Tidal Marshes, Flats and channel and on tyhe particles that are deposited on the flat Ralston, D. K., & Stacey, M. T. (2005). Channels of the Outer Yangtze River Mouth flats. compared to what travels in suspension over Longitudinal dispersion and lateral circulation to a Major Storm. Estuarine Research the flat. It is possible that the finest material in the intertidal zone. Journal of Geophysical Federation Estuaries, 26(6), 1416–1425. does not settle out of suspension and returns Research, 110(C7), C07015, http://doi. back to the channel during ebb tide, and in org/10.1029/2005JC002888 Figure 9. (right) this case only the coarsest fraction will be Ridderinkhof, H., van der Ham, R., & van der A. Displays a sufrace found at the tidal flat surface. Furthermore, Lee, W. (2000). Temporal variations in interposlated (using through coring and trenching the extent of concentration and transport of suspended kernel interpolation tidal flat deposition is constrained. The rate sediments in a channel–flat system in the with barriers) from of current deposition through measured field Ems-Dollard estuary. Continental Shelf the elevantions parameters will be compared to the rates Research, 20(12), 1479–1493. collected, and then required to deposit the extent of sediment http://doi.org/10.1016/S0278- projects elevation of present at depth. 4343(00)00033-9 the high spring tide Straaten, L. M. J. U. van. (1961). Sedimentation over the surface. Conclusion in Tidal Flat Areas. Bulletin of Canadian B. and the mean low Coastal environments are subject to extreme Petroleum Geology, 9(7), 203–226. tide over the surface events (storm surge, coastal flooding, sea- Syvitski, J. P. M., Vörösmarty, C. J., Kettner, A. C. The projected level rise, etc.) and in turn coastlines quickly J., & Green, P. (2005). Impact of inundation surfaces respond to these perturbations. For the humans on the flux of terrestrial sediment to are in good Netherlands, much of the coastline consists the global coastal ocean. Science (New agreement with of intertidal regions that form tidal flats. York, N.Y.), 308(5720), 376–80. http://doi. the extent of fine Much work and insight has been gained org/10.1126/science.1109454 material cover through research on Dutch tidal flats and the Tide Dynamics. (n.d.). from tidal flat sediment transport processes that dictate Tolhurst, T. J., Defew, E. C., Perkins, R. G., sedimentation as their behavior. The current work aims to use Sharples, A., & Paterson, D. M. (2006). The well as observations existing concepts for tidal flats and apply effects of tidally-driven temporal variation from satellite them to the Huanghe delta to ultimately build on measuring intertidal cohesive sediment imagery. a model that capture sediment transport erosion threshold. Aquatic Ecology, 40(4), 42 dynamics for the Huanghe tidal flats. 521–531. 43 Figure 1. Katharine Anarde Tidal inlet features at San Luis Pass, Texas (Wallace et al., 2009) A TALE OF TWO DELTAS - EASTERN SCHELDT, NETHERLANDS AND SAN LUIS PASS, TEXAS, USA

SOUTH WEST DELTA

Katharine is a PhD candidate at Rice Univer- Tidal inlet classification and origin where α and η are empirical coefficients. sity, Houston. Tidal inlets are maintained by tidal currents Through comprehensive investigations of which scour and transport sediment tidal inlets across varying wave and tidal entrained by wave action through the inlet environments in the U.S., Jarrett [1976] Tidal inlets are confined channels in the throat. Sediment carried through the inlet refined O’Brien’s relationship using regression shoreline that connect tidal basins, lagoons, during flood tide is deposited in horseshoe- analysis and recommended α = 9.311 x 10−4 estuaries, and rivers to the coast. Inlets are shaped features called shoals, which are and η = 0.84 for natural inlets along the U.S. commonly utilized for navigation, fishing, and referred to collectively as the flood-tidal Gulf Coast and O’Brien’s α = 7.489 x 10−4 and recreation and therefore play an important delta, or in the bay (Figure 1). On the ebb η = 0.86 for jettied inlets. role in the socio-economic value of the tide, sediment is harvested from the bay, coastal zone (Duong et al., 2016). Ecological back-barrier shorelines, or shoals and then Inlets are often classified in terms of functions in tidal basins also depend on the transported offshore where it is deposited stability which can refer to either channel connection tidal inlets provide to the sea in a seaward lobe called the ebb-tidal delta cross- section or location stability [Duong Figure 2. which help to maintain bay water quality by [Hayes and FitzGerald, 2013, Dean and et al., 2016]. An inlet is deemed cross- Location map flushing pollutants and sediment seaward Dalrymple, 2004]. The morphology and size sectionally stable if the inlet dimensions do depicting the and moderating salinity levels (Dean & of the ebb-tidal delta is a function of the not significantly vary over time. Likewise, Eastern Scheldt Dalrymple, 2004). relative strength of the tidal currents and an inlet is considered locationally stable if estuary, storm surge wave action [Galvin, 1971, Hubbard et al., 1979, the inlet does not migrate over time. Cross- barrier, back- barrier Tidal inlet morphology and behavior are Oertel, 1975]. section stability is typically quantified using dams, dominant governed by complex interactions between Equation 2 or through other empirical ebb channels, and oceanic phenomena (wave action, tidal The size of a tidal inlet is governed principally methods which relate channel hydraulics surrounding features. currents, and mean sea level), underlying by the tidal prism and to second order by to cross sectional area (e.g. the Escoffier Note: ETD = Ebb- geology, estuarine processes, and fluvial input sediment supply from longshore currents. [1977] closure diagram). Bruun and Gerritsen tidal delta. (Hayes & FitzGerald, 2013). Along coasts with The tidal prism is the volume of water that [1960] and Bruun et al. [1978] introduced high littoral transport rates, tidal inlets can flows into a bay from low to high tide and criteria for determining the overall stability migrate downdrift due to sediment deposition can be written as of an inlet, which includes the locational and on the updrift mouth of the inlet. In contrast, cross-sectional stability, by incorporating the along wave-dominated micro-tidal coasts, (1) influence of littoral drift: for example the Texas Gulf Coast, tidal inlets

can sequester sediment leading to erosion where AB is the is the planform bay area (2) on downdrift beaches and barriers. Any tip of (assumed independent of water level), aB is

the delicate balance between hydrodynamic and tidal amplitude in the bay, and aO is the where Mtotal is the total annual littoral drift forcing and sediment supply can considerably ocean tidal amplitude which is equal to half (m3/yr). Using this metric, tidal inlet stability alter tidal inlet behavior and the coasts to the tidal range. The tidal prism is a measure is deemed good (S > 150), fair (S = 100 − 150), which they connect. Understanding the of the amount of tidal mixing within a bay, fair-to-poor (S = 50 − 100), and poor (S < morphological and hydrodynamics effects of and therefore an increase in tidal prism can 50). modifying a tidal inlet is therefore important be interpreted as an increase in bay water for development of effective coastal quality. From the combined work of O’Brien Eastern Scheldt Tidal Delta, Netherlands management policies. This study provides [1931][1967] and later Jarrett [1976], empirical The Eastern Scheldt estuary is an elongated an overview of the effects of an engineered relationships were developed relating the tidal basin located along the southwest coast

intervention on the Eastern Scheldt tidal equilibrium inlet cross section Ac to the of the Netherlands (Figure 2). It is connected inlet, Netherlands to help characterize future spring tidal prism Ωs to the sea through a tide-dominated studies pertaining to the stability of San Luis inlet located between two former islands, 44 Pass tidal inlet, Texas, USA. Schouwen and North Beveland. At the inlet, 45 Figure 3. the mean tidal range is 2.9 m (meso-tidal Grevelingendam and the Volkerakdam in continued channel sedimentation and erosion The Eastern Scheldt regime) and tidal flow propagates through the 1960s and Philipsdam and Oesterdam of ebb shoals and flats will likely result in a inlet viewed from three primary channels, the Roompot, Schaar, in the 1980s. By reducing the basin length smoother ebb-tidal delta in the future. atop the storm surge and Hammen, which are separated by shoals. and planform area, these dams resulted in a barrier looking (left) The Eastern Scheldt inlet has a prominent reduction of net loss in tidal range from 20% San Luis Pass, Texas, USA northwest at toward ebb-tidal delta, which is comprised primarily to 10%. The cumulative effect of the barrier San Luis Pass (SLP) is a locationally stable,

the ebb-tidal delta of coarse sand (d50 ≈ 350 μm) in the channels and dams was a reduction in tidal prism by wave-dominated, micro-tidal inlet that bisects

and (right) northeast and fine sand (d50 ≈ 150 μm) on the shoals approximately 25% (De Bok, 2001; Eelkema et the west end of Galveston Island and the toward the inlet (Eelkema et al., 2013). Prior to the 1960s, the al., 2013). east end of Follets Island on the Upper Texas mouth. Eastern Scheldt estuary was connected to Coast (UTGC) (Israel et al., 1987). The spring two tidal basins to the north and the tidal In the decades that followed, the tidal prism at SLP is 1.7 x 107 m3 and the mean inlet served as a sediment source to the morphological and environmental impacts of tidal range is 0.3 m. SLP is one of the few surrounding system, exporting approximately the Eastern Scheldt storm surge barrier were remaining natural tidal inlets on the Texas 2 Mm3 of sediment per year (Haring, 1978). closely monitored. With construction of the coast and features both a prominent flood- During this time, the tidal prism was on barrier, the effective cross-sectional area of and ebb-tidal delta (Figure 1). East to west average 1200 x 1020 m3 per tide (De Bok, the Eastern Scheldt inlet decreased creating directed littoral transport delivers sediment 2001). Along this portion of the Dutch coast, turbulence and energy head loss across the eroded from Galveston Island to SLP where the offshore wave climate is dominated by barrier [Vroon, 1994]. Despite remaining open it is sequestered in both the flood- and Figure 4. wind waves from the North Sea with minor under normal conditions, this constriction ebb-tidal delta as well as terminal sand flats (a-d) Bathymetric contributions from swell. The tide propagates decreased tidal current velocities through on the updrift tidal inlet bank (Morton et al., elevation (m) as a progressive wave from the southwest to the inlet as well as the tidal range inside the 1995; Wallace et al., 2010). Sand bypassing along the Eastern the northeast and littoral transport is likewise basin. This loss in tidal flow, and therefore at SLP is not continuous but rather event- Scheldt ebb-tidal directed to the northeast (Eelkema, 2013). sediment supply, led to degradation of the driven and therefore sediment is not directly delta be- tween intertidal area including wind-driven erosion transferred from one barrier to the next. Thus, 1984 and 2008 In 1953, a severe winter storm generated a of the tidal flats. Meanwhile, the decrease SLP’s ebb-tidal delta is the primary sediment and (e) cumulative 3 m rise in sea level along the southwest in tidal currents created accommodation source for neighboring Follets Island, a bed-level changes coast of the Netherlands. This storm surge, space within channels which were now too transgressive barrier island that is one of (m) over the same which coincided with the spring tide, lasted large with respect to the modified currents the fastest retreating barriers on the Texas period where red = for two days and led to widespread flooding (Eelkema, 2013). This led the channels to act coast (Paine et al., 2012). Through quantifying accretion and blue = in the system of estuaries, tidal basins, as sediment sinks, trapping sediment eroded sediment volumes from sediment cores, erosion [Eelkema et and islands that comprise the Dutch Delta from the neighboring tidal flats. In terms of Wallace and Anderson (2013) demonstrated al., 2013]. Coast. This event resulted in the death of the sediment budget, the storm surge barrier that unprecedented erosion of Galveston 1,835 people, 30,000 livestock and caused has blocked nearly all sediment transport Island has lead to rapid growth of SLP over extensive property damage and destruction. through the inlet since its construction (Ten the past 200 years and that this primarily can In the wake of this disaster, a plan was Brinke, 1993). be attributed to accelerated sea-level rise and drafted to engineer the coastline such that punctuated impacts from tropical cyclones. the Dutch Delta Coast would be safe against On the seaward side of the barrier, flow The majority of sediment delivered to SLP future flooding. The Delta Plan, as it was patterns were drastically altered due to over the past decade appears to originate called, proposed that the Eastern Scheldt turbu- lence at the barrier. The ebb-tidal delta from beach nourishment projects that occur estuary be completely dammed at the inlet responded to the decrease in cross-shore on the east end of Galveston Island. This is to protect the tidal basin from storm surges. currents through tidal channel reorientation particularly evident through the growth of However, by the 1970s, opposition to this in the direction of longshore currents and the updrift tidal inlet bank by fluvial sand. plan grew due to potential environmental a redistribution of sediment (Eelkema et This lateral accretion is likely caused by wave impacts to fish and wildlife from a reduction al., 2013). Overall, morphological activity in refraction through the inlet and tidal currents in tidal flow. A comprise was reached and by the ebb-tidal delta decreased and mostly acting over a broad sand flat into West Bay 1986 a permeable barrier was constructed negative bed-level changes indicate an (Morton et al., 1995). at the inlet of the Eastern Scheldt. The first erosive trend in the sed- iment budget of its kind, the Eastern Scheldt storm surge (Figure 4). Eelkema et al. (2013) used the Human intervention and climate change barrier (Figure 3) was designed to allow numerical morphodynamic model Delft3D impacts to the UTGC have the potential tidal flow to enter the estuary under normal to attribute this observed decrease in to alter the behavior of SLP, as well as conditions and close during storm events. In sediment transport capacity to an increased the adjoining basins and barriers which it order to restrict a decrease in tidal range due importance in wave forcing. The authors connects. Anderson (2007) suggests that to the barrier, four landward dams were also suggest that the Eastern Scheldt is still removal of sand from the ebb-tidal delta (e.g. 46 constructed in the far reaches of the estuary: far from a morphological equilibrium and for beach nourishment projects) could alter 47 the natural tidal circulation between the Gulf Texas A&M University - Galveston Campus Concluding Research Questions river delta (Wallace et al., 2010). This rapid References A. M. Israel, F. G. Ethridge, and E. L. Estes. A and adjoining tidal basins. Likewise, removal and TU Delft have included extension of While the wave and tidal climate of the UTGC redistribution of sediment is a testament to J. B. Anderson. The Formation and Future Sedimentologic Description of a Microtidal, of sand from the flood-tidal delta could the Galveston seawall to SLP as part of a differs from that of the Netherlands, the power of wave-driven erosion and strength of the Upper Texas Coast. Texas A&M Uni- Flood-Tidal Delta, San Luis Pass, Texas. modify flow velocities, and thereby sediment regional effort to minimize coastal flooding observed morphological effects of human of longshore currents in the region. Therefore, versity Press, College Station, 2007. Journal of Sedimentary Research, 57(2), 1987. exchange, through the inlet. Climate change during extreme storms (Berchum et al., interventions at the Eastern Scheldt shed a reduction in tidal flow through SLP may E. C. Berchum, P. A. L. de Vries, and R. P. J. T. Jarrett. Tidal prism-inlet area driven variations in oceanic (e.g. sea-level rise, 2016). In some iterations of this design, a light onto what mechanisms may influence result in the transport of any sediment J. de Kort. Galveston bay area land barrier relationships. Technical report, Defense wave action), terrestrial (e.g. rainfall runoff), storm surge barrier is incorporated at SLP the behavior at SLP if disrupted from stirred up by wave action downdrift and preliminary design. Technical report, TU Delft, Technical Information Center document, 1976. and atmospheric processes (e.g. hurricane and northward along Mud Island. In addition, equilibrium. For example, the reorientation of consequently, the complete erosion of the Delft University of Technology, 2016. R. A. Morton, J. C. Gibeaut, and J. G. Paine. intensity and frequency) may also affect the U.S. Army Corps of Engineers have tidal channels and redistribution of sediment ebb-tidal delta at SLP. Likewise, a reduction P. Bruun and F. Gerritsen. Stability of coastal Meso-scale transfer of sand during and the stability of SLP through changes to the alluded to sequestering sediment for beach within the Eastern Scheldt ebb-tidal delta in the cross-sectional area of SLP may lead inlets. Coastal Engineering Proceedings, 1 after storms: implications for prediction of tidal prism and littoral transport (Duong et nourishment along Galveston Island from due to the preeminence of the alongshore to sedimentation of flood channels due to a (7):23, 1960. shoreline movement. Marine Geology, 126(1- al., 2016). Recent designs by researchers at the updrift tidal bank at SLP. However, in this current is a likely analog for SLP if modified decrease in flow velocities into the tidal basin. P. Bruun, A. Mehta, and I. Jonsson. Stability of 4): 161–179, Aug. 1995. preliminary design stage, no studies have with a storm surge barrier or gate. After tidal inlets: Theory and engineering, 1978. M. P. O’Brien. Estuary tidal prisms related been conducted to assess the morphological the Brazos River delta (Texas) was diverted In order to better understand how the C. De Bok. Long-term morphology of the to entrance areas. Civil Engineering, 1(8): effects of sediment harvesting, storm surge westward in 1929, the old delta eroded within installation of a storm surge barrier at SLP Eastern Scheldt. Number RIKZ/2002.108x. 738–739, 1931. Figure 6. barriers, and additional coastline hardening a few decades and sediment was transported may impact inlet dynamics, a numerical Rijkswaterstaat, 2001. M. P. O’Brien. Equilibrium flow areas of tidal Eastern Scheldt eastuary on the coastal system. with the longshore current to the new model is needed (e.g. Delft3D). However, R. G. Dean and R. A. Dalrymple. Coastal inlets on sandy coasts. In Coastal Engineering inlet and environmental in researching and learning about the processes with engineering applications. 1966, pages 676–686. 1967. barrier (Image courtesy morphological effects of engineering Cam- bridge University Press, 2004. G. F. Oertel. Ebb-tidal deltas of georgia Rijks waterstaat, photo by interventions at the Eastern Scheldt this T. M. Duong, R. Ranasinghe, D. Walstra, and D. estuaries. Estuarine research., 2, 1975. Joop van Houdt) past summer, it became obvious that Roelvink. Assessing climate change impacts J. G. Paine, S. Mathew, and T. Caudle. there is limited understanding of the first on the stability of small tidal inlet systems: Historical shoreline change through 2007, order controls on SLP’s morphodynamics. Why and how? Earth-Science Reviews, Texas Gulf Coast: rates, contributing causes, Moreover, it is unclear how storms and 154:369–380, Mar. 2016. and Holocene context. Gulf Coast Association hurricanes influence inlet geometry, stability, M. Eelkema. Eastern Scheldt inlet of Geological Societies, 1:13–26, 2012. and evolution of the flood- and ebb-tidal morphodynamics. PhD thesis, TU Delft, Delft W. Ten Brinke. The impact of biological deltas. Therefore, the following preliminary University of Technology, 2013. factors on the deposition of fine-grained research questions were devised: M. Eelkema, Z. B. Wang, A. Hibma, and M. J. sediment in the Oosterschelde (The 1. What is the minimum tidal prism needed to Stive. Morphological effects of the eastern Netherlands). PhD thesis, Universiteit Utrecht, keep SLP open under normal conditions? scheldt storm surge barrier on the ebb-tidal The Netherlands, 1993. 2. Could winter storms and hurricanes exert a delta. Coastal Engineering Jrnal, 55(3), 2013. J. Vroon. Hydrodynamic characteristics of first order control on inlet dynamics? F. F. Escoffier. Hydraulics and stability of tidal the oosterschelde in recent decades. In The 3. Is the morphologic recovery period after inlets. Technical report, Defense Technical Oosterschelde Estuary (The Netherlands): a storms of sufficient duration such that SLP Information Center document, 1977. Case-Study of a Changing Ecosystem, pages can return to an equilibrium state? C. J. Galvin. Wave climate and coastal 17–27. Springer, 1994. processes. Water Environments and Human D. J. Wallace and J. B. Anderson. While numerical modeling is still essential Needs, pages 48–78, 1971. Unprecedented erosion of the upper Texas to answering research questions #2 and #3, J. Haring. History of the development of the coast: Response to accelerated sea-level rise there is limited hydraulic and bathymetric water motion and of the profile of the tidal and hurricane impacts. Geological Society of data available to inform modeling efforts. waters and inlets of the southern delta basin America Bulletin, 125(5-6):728–740, May 2013. Specifically, field measurements of current and the adjacent coastal area during the D. J. Wallace, J. B. Anderson, and A. B. velocities within tidal channels, alongshore periods 1872-1933-1952-1968-1974. Number Rodriguez. Natural versus anthropogenic littoral transport estimates, and pre- and nota K77M031E. Rijkswaterstaat, 1978. mech- anisms of erosion along the upper post-storm bathymetry is needed. Field M. O. Hayes and D. M. FitzGerald. Origin, Texas coast. Geological Society of America efforts are currently under- way to secure Evolution, and Classification of Tidal Inlets. Special Papers, 460:137–147, Jan. 2009. hydrodynamic and bathymetric data in and Journal of Coastal Research, 69:14–33, Nov. D. J. Wallace, J. B. Anderson, and R. A. surrounding SLP during normal conditions, 2013. Fernandez. Transgressive Ravinement versus and if “fortunate”, before and after a storm D. K. Hubbard, G. Oertel, and D. Nummedal. Depth of Closure: A Geological Perspective event. The role of waves and tidal currents in the from the Upper Texas Coast. Journal of development of tidal-inlet sedimentary Coastal Research, 26:1057–1067, Nov. 2010. structures and sand body geometry: examples from north carolina, south carolina, and georgia. Journal of Sedimentary 48 Research, 49 (4), 1979. 49 Figure 1. (right) Sabarethinam Kameshwar Location and ground elevation of tanks in Rotterdam Port area.. UNDERSTANDING VULNERABILITY AND ACCEPTABLE FLOOD

Figure 2. (far right) RISK TO STORAGE TANKS Distribution of roof types. ROTTERDAM PORT

Sabarethinam is a PhD candidate at Rice elevation for all the tanks in the Rotterdam Next, lidar data for the Netherlands, obtained University, Houston. port area. Next, with information on all the from http://www.ahn.nl, is used to evaluate tanks, vulnerability assessment has to be the ground elevation at the base of tanks performed for all the tanks. In this light, and tank height. Ground elevation of tanks’ Above ground storage tanks (ASTs) are the second objective of this study is to base is an important input for vulnerability large cylindrical structures used to store evaluate the vulnerability of tanks for several assessment of tanks for flood scenarios; hazardous materials. ASTs are commonly scenarios, identify the most vulnerable tanks, tanks at low elevations are generally more used in petrochemical facilities and often and suggest potential mitigation measures vulnerable to flooding. Information on times they are located close to navigable based on their level of vulnerability. In ground elevation of tanks is obtained by water ways and water bodies for ease of order to effectively utilize the information extracting the lidar information at the point transporting materials, which makes them on vulnerability of tanks, thresholds for that corresponds to the base of the tank. The vulnerable to hurricanes and floods. In past acceptable risk of tank failure are needed, same procedure is repeated for the point that events, such as hurricanes Katrina, Rita, which would be helpful for comparing represents the top of the tank; the difference Ike, and Evan, catastrophic failures of ASTs mitigation strategies such as a regional level in the elevation between the base and the have been observed (Godoy, 2007, Sengul strategy versus a mitigation strategy at the top of the tank provides an estimate of tank et al., 2012, Hyder, 2008) where tanks level of an individual structure. Therefore, the height. Two separate points are used in this have spilled hazardous material in to the last objective of this study is to review study to distinguish between the base and surrounding environment after becoming existing frameworks that determine the top of the tank because separation of buoyant due to inundation caused by storm thresholds for acceptable risk of failure for locations for tank base and roof enable more surge. In addition to adversely affecting infrastructure systems in order to develop accurate evaluation of tank height and the the environment and incurring litigation similar methods for tanks. ground elevation of tanks. and clean-up costs, such spills also affect the physical and mental wellbeing of the Development of tank information database Using the abovementioned methodology, Figure 3. surrounding communities (Palinkas et al., The database of information on tanks is 3122 tanks are identified and a database Distribution of tank 1993). Since ASTs are vulnerable to hurricane performed by analyzing aerial imagery of the containing information on location, height, diameter and height. and flood events, vulnerability of tanks in the Rotterdam port region. Satellite imagery of diameter, and ground elevation of all tanks Rotterdam port area, which has over 3200 the port region, available in ArcGIS (Beyer, is created. Figure 1 shows the location of all tanks, needs to be studied to understand 2004), is used to locate and identify tanks. the tanks in the Rotterdam port area along the risk to these tanks. With information All the tanks are identified manually and two with the ground elevation for all the tanks. In on vulnerability of tanks, thresholds for points are created in ArcGIS for each tank. Figure 1, all the dots represent tanks and all acceptable risk of storage tank failure may The first point is used to mark the base of the thick solid lines represent existing flood be used to determine if any mitigation the tank and the second point represents protection systems such as dikes. It can be measures are necessary. the top of the tank, the two points help in observed that tanks are spread over the obtaining the height of tanks. For each tank, Europort, Maasvlakte, and Botlek regions. Objectives the diameter is measured using the measure From Figure 1, it can be observed that tanks In order to perform vulnerability assessment tool in ArcGIS and is recorded along with in the Europort and Maasvlakte regions are for all the tanks, a database of information other information such as tank’s roof type. not protected; however, the tanks are located on all the tanks such as location, size, and Tank roof types are classified in to one of the at higher elevations in those regions. While contents are necessary. However, such three categories – fixed roof, floating roof, or the tanks in the Botlek region are protected databases are not available publically. open (no roof). Classification of roof type is by the dikes and the Maeslant barrier, but the Therefore, the first objective of this study important for assessing the vulnerability of elevation of tanks is relatively low which may is to develop a database of tank details tanks for buckling due to flooding and strong increase their susceptibility to failures during consisting of information on tank location, winds. flood events. The range and characteristics 50 height, diameter, roof type, and base of properties of these tanks are shown in 51 Figure 4. (left) Figures 2 to 3. The distribution of roof types Herein, fill levels and the density of contents for two flood scenarios with 3.0m and 5.0m Failure probability of is shown in Figure 2; out of 3123 tanks, 2777 stored in the tanks are assumed to be water elevation above NAP. For 3.0m flood tanks for 3.0m, flood tanks have fixed type roofs; 325 tanks have uncertain. Determining the exact level of scenario, few tanks have failure probability scenario. floating roofs and only 20 tanks have open fill in all of the tanks during a flood event over 5%, which can be attributed to the roofs. Classification of roof type is important is not feasible. Therefore, the fill levels are ground elevation of tanks. Most of the tanks Figure 5. (right) since replacement costs for tanks with assumed to vary uniformly between zero have more than 3.0m elevation; therefore, Failure probability of different roof types are different and their and 90% of the tank height, i.e. all fill levels very low failure probabilities are observed tanks for 5.0m flood performance is also different under external within the considered range are equally likely. for few tanks. However, as the flood level scenario. loads such as floods and strong winds. Figure Furthermore, all the tanks are assumed to be increases to 5.0m large number of tanks in 3 shows the distribution of tank diameter and filled with crude oil whose density is assumed the Botlek region have failure probability over heights for all the tanks in the port region. to follow a uniform distribution with a lower 5%; while, other regions do not see a very Most of the tanks have a diameter of less and upper bound density of 835 and 893 large increase in the number of tanks with than 40.0 m and the tank heights are within kg/m3. For each tank, these uncertainties increased failure probability. 10.0-15.0m range. This figure shows that there are propagated through the fragility models are only few very large tanks with diameters using Monte Carlo simulations. 100000 This observation can be related to the ground over 60.0m. Failure of even a single large simulations are performed for every tank; elevation of the tanks. Tanks outside the tank can cause a catastrophic spill incident, within each simulation, an instance uniformly Botlek region are not protected; therefore, as observed in Murphy oil spill. All this distributed fill level and density of contents they are installed at a higher elevation which information in the tank database is used for is generated to assess if the tank fails. A leads to low failure probability. The Botlek Figure 6. vulnerability assessment of tanks in the Port simulation wherein a tank fails, the spill region, which has 2470 tanks, is situated Comparison of of Rotterdam. volume is evaluated assuming that the in a low lying area. Therefore, even though spill volume for entire contents of the tank are spilled. This the Botlek region is protected, a flood un-anchored and Vulnerability assessment of tanks assumption is conservation since tank failure event which may inundate the region may anchored tanks. In order to perform vulnerability assessment may not necessarily lead to a spill. However, cause a large number of tanks to fail and of an entire portfolio of tanks, methods that considering the environmental, societal, consequently lead to a large number of can facilitate rapid and efficient fragility and economic consequences of a spill – spill incidents. Therefore, further analysis is assessment are required. Only recently, the conservative assumption is warranted. performed for the tanks in the Botlek area Kameshwar & Padgett (In review) have Combining the results from all simulations, with several present and future inundation developed a methodology to support storm the probability of failure and expected spill scenarios for different return periods. surge fragility assessment of a regional for every tank in the port region is obtained. portfolio of tanks. Therein, closed form Inundation levels for the Botlek region for logistics regression models have been First, a preliminary analysis is conducted, 100, 300, 1000, 10000, 4000, and 30000 developed for different failure modes such following the methodology described above, year return period events for years 2015, as flotation of un-anchored and anchored considering fixed levels of inundation over all 2050, and 2100 are obtained from the tanks, buckling of tanks, and system failure the three regions. It must be noted that the Roterdam Port Authority. The scenario events considering flotation and buckling for both constant flood levels correspond to different for 2050 and 2100 consider the effects of sea anchored and un-anchored tanks. These return period events for Botlek and other level rise in the inundation levels. For these fragility models are used here to study regions because Botlek area is protected scenario events, depending on the expected the vulnerability of tanks in the Port of for flooding events while the other regions level of inundation, parts of the Botlek region Rotterdam. The fragility models developed housing tanks are not protected.. In the are assigned inundation a level ranging from in Kameshwar & Padgett (In review) are preliminary analysis, only flotation failure of one to six; each inundation level corresponds developed for tanks designed as per API 650 tanks is considered; wherein, flotation of a to the following inundation range: 0.01- (API, 2013), which provides guidelines for tank is termed as failure and subsequently 0.10m, 0.10-0.25m, 0.25-0.50m, 0.50- 1.00m, designing tanks for oil storage. the entire contents of the tank are assumed 1.00-2.00m, and over 2.00m, respectively. to be spilled. Herein, flood levels are varied Since a range of inundation is provided Even though tanks in the Rotterdam port from 2.0 to 6.0 m over NAP across the entire for parts of the Botlek region, uncertainty region may be designed using a different region. Considering the flood level and the in the inundation level is propagated in design guideline, the difference in the final ground elevation at the base of the tank, the Monte Carlo simulations to evaluate design in comparison to a design based on effective inundation depth at tank locations failure probability and spill volumes. For API 650 is not expected to be significant to is evaluated. For example, assuming a ground each inundation level a uniform distribution affect the fragility of tanks. Therefore, the elevation of 2.5m will lead to zero and 0.5m is assumed within the range of expected fragility functions developed in Kameshwar & effective inundation for 2.0 m and 3.0m flood inundation. The inundation level at tank Padgett are used to study the vulnerability of level events respectively. Figures 4 and 5 locations for any of the scenarios, even the 52 tanks in the Rotterdam port region. show tanks with non-zero failure probability 30000 return period event in 2100, did not 53 Figure A1-4 exceed 2.00m. Therefore, buckling failure of risk of tank failure, are required. The next environmental and societal losses and loss (left column). tanks is neglected here since buckling failure section discusses the existing methods for of life, which are difficult to quantify and the Failure probability of is unlikely at of 2.0m or lower inundation determining acceptable risks for failure of morality of associating monetary values to tanks in 2015 levels. The 100 and 300 year return period infrastructure and provides a brief discussion life and environment are also questioned A1. for 1000 year scenarios for 2015 did not lead to any tank on a proposed way for determining (Reid, 2000). Another interesting criterion return period event. failures and even for the 1000 year event acceptable thresholds. for determining acceptable risk is provided A2. for 4000 year only few tanks non-zero failure probability. by NORSOK, safety standards developed return period event. However, the number of tanks with significant Brief review of existing methods for deciding by Norwegian petroleum industry. As per A3. for 10000 year failure probability increases for 4000, 10000 acceptable risk the NORSOK guidelines: “the duration of return period event. and 30000 year return period events. The cost of averting a ton of oil spilt (CATS) environmental damage shall be insignificant A4. for 30000 year Flooding scenarios for the future, years is one of the commonly used methodologies in relation to the expected time between return period event. 2050 and 2100, see a significant increase in used to assess preventive measures for oil such events” (NORSOK, 1998). Effectively, this the number of tanks with non-zero failure tanker spills. A mitigation measure may be guideline leaves the selection of acceptable Figure A5-8 probability. Maps with failure probability of selected if the cost of the measure is less risk to the facility owners. (right column). tanks for all the scenarios are presented in than the factored cost of an oil spill, which Failure probability of the Appendix A. is obtained by multiplying the cost by an Interaction with Dutch experts also provided tanks in 2050 assurance factor; this factor is decided several insights on how the risks are A5. for 300 year Interestingly, the maximum failure probability by decision makers (Vanem et al., 2008, managed and thresholds for acceptable return period event. for any tank in the Botlek region for any Psarros et al., 2011). One of the drawbacks risk are derived in the Netherlands. Most of A6. for 1000 year of the scenarios does not exceed 30%. of this methodology is that environmental the risk thresholds used in the Netherlands, return period event. Large return period events are observed to and societal costs of oil spills are difficult such as the threshold on individual flood risk A7. for 1000 year inundate larger extent of areas; however, the to quantify. Under or overestimation of of 1 in 100000 and the individual risk due return period event. level of inundation is not observed to increase environmental and social costs may lead to hazardous facilities have been primarily A8. for 4000 year with increase in the return period. This trend to different measures, which may pose developed for reducing loss of life. However, return period event. is also observed for future flooding scenarios. difficulties in properly evaluating the in case of above ground storage tanks, failure Since the maximum inundation levels do mitigation measures. due to floods, usually, does not pose a direct not increase significantly, the observed threat to peoples’ lives in the vicinity of failed maximum failure probability also does not Another commonly used principle is the tanks. Therefore, the existing frameworks increase as the return period increases. Since as low as reasonable possible/achievable used to develop risk thresholds in the low failure probabilities are observed, this (ALARP/ALARA) approach, which is Netherlands, some of which are discussed in study suggests anchoring tanks as a possible commonly used in the UK, the Netherlands, Jonkman et al. and Vrijling et al. (Jonkman mitigation measure. Considering, 25.4mm and other countries. In this framework, et al., 2011, Vrijling et al., 1998), may not be diameter anchor bolts spaced at of 3.0m the different risk regions are defined where directly applicable to determine the risk failure probability of each is tank is evaluated the risks are unacceptable, tolerable, and thresholds for failure of ASTs. for all the scenarios. acceptable. The ALAPR principle aims to balance the costs and corresponding benefits Furthermore, all the methods used to derive In order to show the effectiveness of of actions to determine necessary mitigation acceptable risk levels involve judgement anchoring the tanks, Figure 6 compares measures. ALARP has been used to and need involvement of stake holders. the spill volumes for each scenario, with determine thresholds for individual risks due The inherent presence of judgement in and without anchors. As can be seen in to hazardous installations in the Netherlands risk management has been underscored Figure 6, the spill volumes increase as the by the ministry of housing, spatial planning by Stewart and Leschine (1986) et al. return period increases and also large and environment (Jonkman et al., 2003). who suggest that judgement may not be increase in spill volumes can be observed for ALARP methodology has been criticized for avoided since risk management involves future inundation scenarios. However, in all lacking objectivity, transparency, openness, complex issues. Therefore, development scenarios, anchoring the tanks reduces the and public participation (Melchers, 2001). of risk thresholds for entire the entire spill volumes by over three times. In order Rotterdam port region or for similar regions to further decrease the spill volumes, the Cost benefit analysis are also often used to like the Houston Ship Channel is beyond anchor spacing may be reduced. Therefore, select strategies from available options to the scope of this study. However, this anchoring tanks may be considered as a mitigate risks (Padgett et al., 2010). It has also study is developing a framework to derive potential structural level mitigation measure. been used in the Netherlands to determine structure specific acceptable risk thresholds However, in order to decide if anchoring the safety standards for flood protection based on a regional level threshold, which is required and determine how much systems considering economic, social may be decided by local stakeholders, for anchoring is required, acceptable levels of and individual risk. However, cost benefit infrastructure systems including storage 54 spill volumes, i.e. acceptable threshold for analysis require numerical cost estimates for tanks and bridges. The framework, whose 55 Figure A9 (right) development is currently in its preliminary References assessment. Risk Analysis 6, 305-315. Failure probability of stage, disaggregates the regional risk API 2013. 650: Welded steel tanks for oil Vanem, E., Endresen, Ø. and Skjong, R. 2008. tanks in 2050 due to individual structures or a group of storage. Washington, DC: API. Cost-effectiveness criteria for marine oil spill for 30000 year structures by assessing their contribution Beyer, H. L. 2004. Hawth’s analysis tools for preventive measures. Reliability Engineering return period event. to the total regional risk. The required arcgis. & System Safety, 93, 1354-1368. reduction in the risk for a structure will be Godoy, L. 2007. Performance of storage Vrijling, J., Van Hengel, W. and Houben, R. directly proportional to the contribution of tanks in oil facilities damaged by hurricanes 1998. Acceptable risk as a basis for design. the structure to the overall region’s risk. This katrina and rita. Journal of Performance of Reliability Engineering & System Safety, 59, approach will ensure that, overall, the region’s Constructed Facilities, 21, 441-449. 141-150. risk targets are met while target risk levels for Hyder, M. (ed.) 2008. Oil spill intelligence individual structures reflect their contribution report, assessment of hurricane ike damage to the total risk. continues: Aspen Publishers. Jonkman, S., Van Gelder, P. and Vrijling, J. Summary 2003. An overview of quantitative risk Figure A10-15. This study has developed a database measures for loss of life and economic damage. Failure probability of consisting of information on all the tanks Journal of Hazardous materials 99, 1-30. tanks in 2100 in the Rotterdam port region to facilitate Jonkman, S. N., Jongejan, R. and Maaskant, B. flood vulnerability assessment of tanks. 2011. The use of individual and societal risk (left column) The database consists of information on criteria within the dutch flood safety policy— A10. for 100 year tanks’ height, diameter, ground elevation nationwide estimates of societal risk and return period event. and roof type. Using information from this policy applications. Risk Analysis 31, 282-300. A11. for 300 year database, a preliminary vulnerability analysis Kameshwar, S. and Padgett, J. E. In review. return period event. is performed which shows that tanks in the Storm surge fragility assessment of above A12. for 1000 year Botlek region are more susceptible to flood ground storage tanks. Structural Safety. return period event. damage compared to tanks in other regions Melchers, R. E. 2001. On the alarp approach such as the Europort and the Maasvlakte. to risk management. Reliability Engineering & (right column) Therefore, a detailed vulnerability assessment System Safety, 71, 201-208. A13. for 4000 year is performed for tanks in Botlek region for NORSOK 1998. Risk and emergency return period event. various inundation levels corresponding to preparedness, (z-013 rev.1). Annex C: A14. for 10000 year return periods ranging from 100 to 30000 Methodology for establishment and use of return period event. years for present and future conditions. environmental risk acceptance criteria A15. for 30000 year (http://www.standard.no/pagefiles/953/z- return period event. Analysis of inundation levels at tank locations 013r1.pdf). for all the scenario reveals that inundation Padgett, J. E., Dennemann, K. and Ghosh, levels do not exceed 2.0m, which eliminates J. 2010. Risk-based seismic life-cycle cost– tank shell buckling as one of the possible benefit (lcc-b) analysis for bridge retrofit failure modes. The results of the vulnerability assessment. Structural Safety, 32, 165-173. analysis of tank in the Botlek region provide Palinkas, L., Downs, M., Petterson, J. failure probabilities and spill volumes and Russell, J. 1993. Social, cultural, and associated with each tank. In all scenarios, psychological impacts of the exxon valdez oil the failure probability of tanks is observed spill. Human Organization, 52, 1-13. to be less than 0.3, which is attributed to Psarros, G., Skjong, R. and Vanem, E. 2011. the low inundation levels. Therefore, this Risk acceptance criterion for tanker oil spill study proposes anchoring of tanks to reduce risk reduction measures. Marine Pollution the vulnerability of tanks. Anchoring tanks Bulletin 62, 116-127. actually reduces the spill volumes by up to Reid, S. G. 2000. Acceptable risk criteria. three times, which shows the effectiveness Progress in Structural Engineering and of anchors; further decrease in spill volumes Materials 2, 254-262. may be achieved by increasing the number Sengul, H., Santella, N., Steinberg, L. J. and of anchors for each tank. Furthermore, Cruz, A. M. 2012. Analysis of hazardous this study is also developing a framework material releases due to natural hazards in to derive structure specific, herein tanks, the united states. Disasters, 36, 723-743. risk thresholds based on the regional risk Stewart, T. R. and Leschine, T. M. 1986. 56 thresholds. Judgment and analysis in oil spill risk 57 Figure 1. Matthew M. Malecha Neighborhoods in Feijenoord District, with locator maps of SPATIAL EVALUATING THE NETWORK OF PLANS AND FLOOD the Netherlands and Rotterdam environs. VULNERABILITY ROTTERDAM CITY - FEIJENOORD DISTRICT

Matthew is a PhD candidate at Texas A&M 2016). It may also include plans focused Plan Integration for Resilience Scorecard University, College Station. on a particular sector of the urban system technique. such as land use, hazard mitigation, housing, transportation, parks and recreation, or Although contextual differences necessitate Damages and costs associated with flood capital improvements (Berke et al. 2015). slight modifications, the core of the process events are mounting as a result of a changing is retained, thus providing support for climate, an increasingly urbanized and Berke et al.’s Plan Integration for Resilience the generalizability and utility of the Plan coastal populace, and local land use and Scorecard (formerly known as the resilience Integration for Resilience Scorecard analytical development decisions (Moser et al. 2014; scorecard) allows the spatial evaluation of method beyond the United States—even in Kousky 2014). National and international community network of plan documents, a place famous for its flood management. governmental organizations have responded giving planners and decision-makers new Furthermore, application of the scorecard with calls for research and implementation perspective regarding the coordination analysis in the Netherlands and comparison of climate change mitigation, adaptation, and efficacy of their policy responses to of results with U.S. cases allows a nuanced and resilience-building measures (IPCC coastal flooding (Berke et al. 2015). The exploration of the ways hazard planning and 2014). In 2012, the United States National development of this method is an important governance affect plan quality and efficacy, Research Council (NRC) recommended step toward answering the calls of the NRC adding to the important and growing body development of a “resilience scorecard” and UN and achieving the kind of plan of knowledge on this subject (cf. Burby et Figure 2. to help communities “track their progress coordination long advocated by hazard al. 1997; Berke 1996; Brody 2003; Ward et al. 3D model showing toward resiliency” (NRC 2012, p. 12). As part planning specialists (Godschalk et al. 1998). 2013). land elevation in of the 2015 Sendai Framework, the United Plan Integration for Resilience Scorecards central Rotterdam Nations (UN) declared that consistent offer planners and researchers a powerful Because the study is ongoing, this paper (looking west, down integration of hazard mitigation policies is new way of simultaneously evaluating focuses primarily on the methodology and the Nieuwe Maas; critical to effecting resilience, and that the community vulnerability, policy response, context of the Plan Integration for Resilience brown = higher failure of many communities to do so is a and plan integration. Areas of the community Scorecard analysis in the Netherlands. elevation; blue = critical international concern (United Nations demonstrating plan conflict or vulnerability– Preliminary results are also presented. In lieu lower elevation). General Assembly 2015). policy discrepancies can be targeted by of recommendations, the paper concludes Most of Feijenoord policymakers (Berke et al. 2015). with a brief discussion of expectations for the District is shown Berke and colleagues (2015) developed and remainder of the study and future research in the left-central tested a resilience scorecard that focuses By way of expanding and validating that directions. foreground (red on the integration and responsiveness approach, this study applies the Plan dotted line). The of a community’s network of plans vis-à- Integration for Resilience Scorecard Hazard Planning and Networks of Plans in the island in the river is vis physical and social vulnerability and methodology in an international setting, Netherlands the Noordereiland coastal flooding hazards. Communities specifically to a relatively vulnerable district in Research has shown that communities that neighborhood. often adopt multiple plans (which together the port city of Rotterdam, the Netherlands. plan for hazard mitigation through proactive The sharp border constitute a ‘network’) that guide their While an internationally acknowledged leader land use policies are more resilient; that is, between light blue future development and management, in flood safety (Ward, Pauw, Van Buuren, they are better able to anticipate, absorb, and and brown areas including in hazardous areas (Berke et al. & Marfai 2013), Rotterdam is nevertheless effectively respond to hazard events (Burby along the river 2015). A plan network frequently includes highly exposed to flood hazards, particularly et al. 1997; Adger et al. 2005). Unfortunately, generally indicates a comprehensive plan, the community’s as climate change begins to alter patterns integrative hazard planning is currently the presence of primary guiding and coordinating policy of precipitation and glacial melt (City of the exception, rather than the rule, in many a dike (Source: I. document (Berke, Godschalk, & Kaiser 2006) Rotterdam 2013; IPCC 2014). The city also communities around the world (Burby Bobbink, TU Delft, via and a hazard mitigation plan, adopted by demonstrates at least a measure of spatial et al. 1999; Macintosh 2013). Coordinated City of Rotterdam local governments as a prerequisite for plan conflict, making it a suitable candidate hazard and land use planning has existed for 58 (2013)) federal disaster mitigation funding (FEMA for the novel perspective offered by the centuries in the Netherlands, however, and 59 relatively strict regulations are by and large administrative bodies working at different divided into nine neighborhoods (buurten): accepted as a social good, integral to the scales (Hobma & Schutte-Postma 2010). The Noordereiland, Wilhelminapier (also known maintenance of safety and a high standard of country’s 12 provinces and 440 municipalities as Kop van Zuid), Kop van Feijenoord living (Van der Valk 2002). share spatial planning obligations, with (also known as Kop van Zuid-Entrepot), the latter responsible for approving and Feijenoord, Katendrecht, Afrikaanderwijk In many ways, this is a consequence of the enforcing the sub-municipal water plan (also known as Afrikaanderbuurt), Bloemhof, country’s long and complicated history (deelgemeentelijk waterplan) and land Hillesluis, and Vreewijk. Each of these with water (cf. Borger & Ligtendag 1998). use plan (bestemmingsplan) documents neighborhoods is an official city planning unit The Dutch were draining coastal wetlands that direct land use at the district and and has its own unique, detailed land use plan for agricultural purposes at least as far neighborhood scales, respectively (ibid.). (bestemmingsplan). back as the 11th century, and protecting ‘Functional decentralization’ also exists, this investment has required significant and particularly with respect to water: 27 regional Several of the northern neighborhoods continuous engineering and planning efforts Water Authorities, which possess certain are in the midst of large-scale, high profile ever since (Wesselink 2007). Still, with 60% of legislative and taxing powers, manage redevelopment projects. Wilhelminapier is its surface area of 34,000 km2 located below the country’s complex relationship with transforming into an extension of the city sea level and/or adjacent to rivers, lakes, or water, focusing on quantity, quality, and center (Stadscentrum), with iconic high-rise the sea (Van Alphen 2015), the Netherlands safety issues (ibid.). The unique ‘water test’ office buildings and mixed-use developments is one of the most exposed countries in the (watertoets) legally binds land use and (Doucet, Van Kempen, & Van Weesep 2011). world with respect to coastal and riverine water planning by requiring municipalities Others, especially those located in the south, flooding, especially in an era of increasing to “consult with Water Boards where the are more typical of traditional Dutch urban climatic uncertainty (City of Rotterdam preparation of land-use plans is concerned” neighborhoods, dominated by residential 2013). The Netherlands has a troubled history (ibid., p. 15). Flood-hazard-related policies and neighborhood-oriented commercial land of floods, including an epic 1953 event may therefore be found in many parts of uses. that devastated the country’s southwest a Dutch community’s (theoretically) well- and precipitated the modern era of Dutch integrated network of plans. Like much of Rotterdam, the majority of water management, in which flood risk is a southern Feijenoord District is located fundamental driver of policymaking (Correljé Given this refined and deliberate approach, below sea level (indicated by blue coloring & Broekhans 2015; Jonkman, Kok, & Vrijling applying the Plan Integration for Resilience in Figure 2) but is embanked, or protected 2008). Scorecard method in a Dutch city is an from riverine flooding by an extensive dike important opportunity, both in terms system (City of Rotterdam 2013; Ward et al. Today the small, densely populated nation of testing its generalizability and as a 2013). The thick black line in Figure 1 shows of 16.8 million inhabitants (500 persons/ new perspective on plan integration and the location of the south bank dike relative km2) (2014 values; Centraal Bureau voor de responsiveness in a country famous for urban to Feijenoord’s neighborhoods. Vreewijk, Statistiek [CBS] 2016) is world-renowned planning and water management expertise. Bloemhof, and all but a small, uninhabited for its sophisticated planning and flood risk The following sections will describe the study portion of Hillesluis are located behind the management strategies, which combine area and then summarize the Plan Integration dike, as is the majority of Afrikaanderwijk. engineering and policy interventions to keep for Resilience Scorecard methodology as Flood safety in these areas is the the Netherlands and its people safe from applied in the Dutch context. Preliminary responsibility of the regional Water Authority, harm (Ward et al. 2013). However, projected findings will then be presented, and the which manages the dikes to prevent changes in climate and land use threaten to paper will conclude with a brief discussion of overtopping or failure (Correljé & Broekhans upset this delicate balance, and the official expectations for the remainder of the study 2015). A very high safety standard has been ‘resistance strategy’ of attempting to prevent and future research directions. set by the national government, and thus all flooding has begun to give way to a more annual flood risk in the embanked part of flexible ‘resilience’ approach, which seeks to Feijenoord District, Rotterdam, the Feijenoord District is estimated at 1 in 4,000 minimize the consequences of flooding (Vis Netherlands (Jonkman et al. 2008). Still, in the unlikely et al. 2003; Klijn, van Buuren, & van Rooij, For the Dutch application of the Plan event of a dike breach or extraordinarily 2004) as an integral part of a multi-layer Integration for Resilience Scorecard high river levels, damage to the low-lying water safety plan (Kaufmann, Mees, Liefferink, method, the study site is the district (wijk) neighborhoods would be catastrophic (City & Crabbé 2016). The full scope of effects of of Feijenoord, located south of the Nieuwe of Rotterdam 2013). this policy shift is as yet unknown. Maas River in central Rotterdam, the second largest city in the Netherlands and the The remainder of the district – including Planning and building regulations in the largest port in Europe (Figure 1). Feijenoord the Noordereiland, Feijenoord, Kop van Netherlands are centrally authorized, but is a densely populated urban district with Feijenoord, Wilhelminapier, and Katendrecht 60 powers are distributed among multiple more than 70,000 residents (CBS 2016). It is neighborhoods, as well as part of 61 Photo previous page.: Afrikaanderwijk – is located on higher ground (304 and 312 per 1000, respectively), two evaluating plans at the community-wide scale values (dark red) near the city center. The Rotterdam Feijenoord but is unembanked (Figure 2). Being directly indicators of social vulnerability (CBS 2016; and reducing ecological fallacy concerns (cf. Dutch government’s national statistical at high river level exposed to the river, these neighborhoods Weetmeer 2016). Both physical and social Piantadosi, Byar, & Green 1988). The existence bureau (CBS) maintains a wealth of (Photo courtesy have a greater probability of flooding, though vulnerability will be described in more detail of neighborhood-scale land use plans in data aggregated at the neighborhood Defacto, Rotterdam) inundation and damages are mitigated by the below, but these brief examples suggest an the Netherlands, and their importance for scale, including mean housing valuation higher elevation (City of Rotterdam 2013). uneven distribution of vulnerability across guiding land use and planning policy, makes (Woningwaarde [WOZ]), which is used as a Responsibility for safety and recovery in Feijenoord District’s neighborhoods—another the neighborhood the ideal ‘planning zone’ proxy for physical vulnerability in this analysis Figure 3. (right) unembanked areas is more ambiguous than reason for its selection as a study site. in Feijenoord District. Figure 3 (Step 1) (see Figure 4a). Illustration of the in embanked areas, though it appears to be shows eight numbered neighborhoods in an three-step Plan shared by the municipality and individual Plan Integration for Resilience Scorecard example community. Social vulnerability is computed using a ‘flag Integration for developers (Ward et al. 2013; {personal Analysis in the Netherlands count’ indexing procedure developed by the Resilience Scorecard interview citations}). The Plan Integration for Resilience Hazard zones are then delimited and U.S. Centers for Disease Control (Flanagan method. Scorecard method was originally developed intersected with the neighborhoods to create et al. 2011). Population statistics for key Feijenoord District was selected for several to advance the understanding of plan a new layer of neighborhood hazard zones, social vulnerability indicators representative reasons, including its location along the lower integration and responsiveness with respect which are the ultimate unit of analysis for the of four domains of social vulnerability stretches of a navigable river, which makes to flood exposure and vulnerability in U.S. study. All neighborhoods in Figure 3 (Step – socioeconomic status, household it naturally exposed to both storm surge communities. In the American context, 1) include two hazard zones, denoted by the composition, minority status, and housing and riverine flooding. Massive engineering coastal flood hazard exposure is captured extent of the light blue hatched and light blue and transportation (ibid.) – are collected at works – including the extensive dike system, using the current 100-year floodplain and an dotted zones. Several neighborhoods also the neighborhood scale. Each indicator is systematic elevation of riparian land, and approximation of its extent when accounting contain lands excluded from the analysis (no then ranked across the study neighborhoods, construction of the Maeslant storm surge for future sea-level rise. These hazard zones color). the most vulnerable districts are given a ‘flag’ barrier (Maeslantkering) – have reduced are appropriate given the nation’s history for that variable, and the flags are summed much, though not all, of this risk (de Moel, of flooding events, the character of regional In Rotterdam, decades of altering the local for each neighborhood (Berke et al. 2015). H., van Vliet, & Aerts 2014; City of Rotterdam flood hazards, and American land use landscape by elevating land and constructing To determine social vulnerability in the 2013). Although current Dutch safety planning and governance (cf. Mileti 1999). dikes has greatly affected the circumstances Feijenoord District, CBS data aggregated at standards are very high, especially from an Measures of physical and social vulnerability of neighborhood flood exposure (Ward et al. the neighborhood level are gathered for 11 American perspective, some uncertainty and are also grounded in American hazard 2013). Thus, for the application of the Plan key variables {explained in greater detail in vulnerability remains, particularly with respect and vulnerability literature (cf. Patterson Integration for Resilience Scorecard method the future}and indexed using the flag count to unembanked areas (de Moel, Bouwer, & & Doyle 2009; Flanagan et al. 2011). In the in Feijenoord, the hazard zones used for procedure (see Figure 4b). Aerts 2014). And while some of Rotterdam’s Netherlands, circumstances differ with analysis are the embanked and unembanked policy professionals are cognizant of the respect to the history and character of areas. This allows for detailed analysis Step 3: Evaluate the Network of Plans and threats posed by an ever more unpredictable hazards and vulnerability, land use planning of the ways policies across the district’s Generate a Plan Integration for Resilience climate, including changes in the intensity norms, and governance and administration, network of plans apply to neighborhoods Scorecard and seasonality of rainfall (City of Rotterdam necessitating several methodological with very different flood risks. All Feijenoord The final step in the process is the spatial 2013), the ways this concern is borne out in adjustments. District neighborhoods are located in at evaluation of the community’s network planning and policy across the network of least one hazard zone. Afrikaanderwijk is of plans through the creation of a Plan plans is not yet well understood. This section will generally describe the the only neighborhood with residents and Integration for Resilience Scorecard. To three main steps of the Plan Integration for buildings in both zones, though again, a construct the scorecard, policies that Relative to other areas in Rotterdam, parts Resilience Scorecard process (visualized in small, uninhabited part of Hillesluis is also influence land use and development are of Feijenoord District are also especially Figure 3), which include the (1) delineation of unembanked (Figure 1). identified in each of the community’s plan physically and socially vulnerable. For planning and hazard zones, (2) establishment documents. These are then spatially assigned example, the Wilhelminapier neighborhood of physical and social vulnerability levels Step 2: Determine Physical and Social to neighborhood hazard zones and scored has among the highest mean housing values for each zone, and (3) evaluation of the Vulnerability according to their effect on physical or social in the central city, €229,000 in 2013 (CBS community’s network of plans for integration Physical and social vulnerability are then vulnerability (Berke et al. 2015). Policies that 2016; Weetmeer 2016), which connotes high and responsiveness to vulnerability by zone determined for each of the neighborhood increase vulnerability receive scores of “-1”, physical vulnerability (see Step 2, below). (Berke et al. 2015). Explanations of how each hazard zones. Consistent with Berke et while those that reduce vulnerability receive Neighborhoods like Afrikaanderwijk and step is applied in the Feijenoord District case al. (2015) and other studies (Patterson & a “+1” score. Scores are then totaled for Feijenoord, in contrast, have relatively low study are also included. Doyle 2009; National Oceanic Atmospheric each neighborhood hazard zone to create housing values but are home to some of Administration 2015; Southeast Florida a policy score index. Higher scores indicate the city’s largest non-Western-European Step 1: Delineate Planning and Hazard Zones Regional Compact 2012), physical greater policy focus on reducing vulnerability. immigrant communities (80% and 75%, Delineating planning zones divides the city vulnerability is defined using a mean Negative scores suggest that the plan may respectively, in 2013) and highest rates of into smaller units that can be individually parcel value measure. Figure 3 (Step 2) actually increase flood vulnerability in the households receiving general assistance evaluated and compared, allowing for a finer- displays physical vulnerability across the neighborhood hazard zone (Berke et al. 62 benefits (Algemene bijstanduitkeringen) grained spatial analysis than is possible by neighborhood hazard zones, with highest 2015). 63 Maps of vulnerability (darker red = greater show the scores for map); Sub-municipal Figure 3 (Step 3) presents the mapped is a high-level direction-setting document respect to the spatial focus and magnitude and plan scores vulnerability). Map the individual plans Water Plan (e); results of a complete scorecard, revealing produced by the City of Rotterdam in 2013. of land use and development policies in for neighborhoods (c) displays the (‘colorblind safe’ and Rotterdam the disparity in total policy scores across the It summarizes the threats posed to the Feijenoord District, as shown in Figure 4c, in Feijenoord overall composite coloring scheme: Climate Change example community’s neighborhood hazard city by climate change and outlines the which is a composite map that displays the District. Physical policy score for pink = negative; Adaptation Strategy zones. Using a ‘colorblind-safe’ pink-to-green municipality’s chosen path forward (City of overall policy scores across all three plan (a) and social (b) each neighborhood green = positive): (f). The thick black color scale , some neighborhood hazard Rotterdam 2013). More of a vision statement categories and nine separate plans. {At least vulnerability are across the entire Neighborhood line depicts the zones are shown to have negative overall than a policy document, the Rotterdam two more land use plans will be included illustrated in the network of plans. Land Use Plans (d; approximate location policy scores (pink). Others are positive Climate Change Adaptation Strategy in the final analysis, for the Hillesluis and first two maps The remaining maps all shown on one of the dike. (green), representing a vulnerability-reducing nevertheless contains detailed narratives and Wilhelminapier neighborhoods, along with policy emphasis. ‘perspectives’ sections which include several several other larger-scale plans.} All districts strong and potentially influential place- receive positive overall scores, however. The The network of plans in Feijenoord, specific policy statements. embanked portion of Afrikaanderwijk has Rotterdam includes three categories the highest overall score (+18), followed by of documents that guide land use and Preliminary Findings its unembanked section, Kop van Feijenoord, development. These include: The Plan Integration for Resilience Scorecard Bloemhof, and then Vreewijk. Katendrecht • Neighborhood Land Use Plans analysis of Feijenoord District is ongoing. scores lowest (+1), while the scores for (Bestemmingsplannen) Preliminary findings will be presented in Feijenoord, Noordereiland, Wilhelminapier, In the Netherlands, local land use planning this section, beginning with a description of and Hillesluis are moderately high. is regulated by a detailed, neighborhood- physical and social vulnerability in the district. scale document, the bestemmingsplan. This Plan scores will then be discussed, followed Closer inspection of the individual plans land use plan has legal standing, akin to a by an examination of the relationship between reveals patterns behind these findings. Strong U.S. community’s zoning ordinance, but also patterns of vulnerability and plan scores. disparities are found when the land use plans acts as a vision statement and development of individual neighborhoods are compared guide (Hobma & Schutte-Postma 2010). Each Preliminary Findings: Vulnerability (Figure 4d). Land use plans in Katendrecht of Feijenoord District’s nine neighborhoods Preliminary results show a wide range in and Noordereiland – both in the unembanked has its own land use plan. For the sake of this physical vulnerability throughout Feijenoord part of Feijenoord District – include more analysis, these were compiled into a single District (Figure 4a) – measured using 2013 policies focused on development than scorecard and map (Figure 4d), though each mean housing values (WOZ) for each flood mitigation, and this is reflected in bestemmingsplan acts like a regulatory small neighborhood – from a high of €229,000 their negative policy scores (-10 and -1, area plan for an individual neighborhood. in the rapidly redeveloping Wilhelminapier respectively). In contrast, the Afrikaanderwijk to a low of €95,000 in Afrikaanderwijk and Bloemhof land use plans strongly • Sub-municipal Water Plan for the districts (CBS 2016). Bloemhof and Hillesluis join emphasize reduction of flood vulnerability of Charlois and Feijenoord (Deelgemeentelijk Afrikaanderwijk as the least physically in the embanked areas. Land use plans in waterplan Charlois en Feijenoord 2011-2016) vulnerable neighborhoods, followed Vreewijk and Kop van Feijenoord are more The sub-municipal water plan is a policy by Feijenoord. Kop van Feijenoord and measured in their approach, though both document produced by a consortium of Noordereiland are almost as physically are positive. The Feijenoord neighborhood’s administrative bodies, including the local vulnerable as Wilhelminapier, while land use plan is split; some policies favor Water Authority, the department of water Katendrecht and Vreewijk are moderately so. development, while other enhance flood management of the municipal services resilience. (Gemeentewerken), and the affected sub- According to the flag count analysis (Figure municipal districts—in this case, Charlois 4b), the Feijenoord neighborhood is the most The sub-municipal water plan (Figure 4e), and Feijenoord (Hobma & Schutte-Postma socially vulnerable in the district (10 out of 11 contains many policies likely to reduce flood 2010). Water plans have a strong focus possible flags), followed by Afrikaanderwijk vulnerability, though somewhat more so in on capital improvements and are used to (8 flags). Hillesluis is also among the district’s the embanked neighborhoods—particularly guide the implementation of water-related most socially vulnerable places, being in Vreewijk, which scores highest of all (+5). policy in Dutch cities. Sub-municipal water flagged on five different variables. Bloemhof, The Rotterdam Climate Change Adaptation plans are district-level components of a Vreewijk, Katendrecht, Wilhelminapier, and Plan (Figure 4f), on the other hand, places municipal water plan—in this case, the Noordereiland each receive fewer than three more emphasis on the unembanked revised Rotterdam Water Plan (Waterplan 2 flags, indicating moderate to low relative neighborhoods, though its land use Rotterdam). social vulnerability. Kop van Feijenoord is the recommendations focus on flood vulnerability least socially vulnerable of all (0 flags). reduction as a rule. Hence all neighborhoods • Rotterdam Climate Change Adaptation receive strongly positive policy scores for this Strategy (Rotterdamse Adaptatie Strategie) Preliminary Findings: Plan Scores plan (at least +7). 64 The Climate Change Adaptation Strategy Considerable inconsistency exists with 65 (Left) Street view References de Moel, H., van Vliet, M., & Aerts, J. C. Moser, S. C., M. A. Davidson, P. Kirshen, P. in Afrikaanderwijk, Adger, W. N., Hughes, T. P., Folke, C., (2014). Evaluating the effect of flood Mulvaney, J. F. Murley, J. E. Neumann, L. Rotterdam. Carpenter, S. & Rockstrom, J. (2005). Scial- damage-reducing measures: a case study Petes, and D. Reed. (2014). Ch. 25: Coastal Ecological Resilience to Coastal Disasters. of the unembanked area of Rotterdam, the Zone Development and Ecosystems. Climate (Right) Harbor, souht Science 309, 1036-1039. Netherlands. Regional environmental change, Change Impacts in the United States: The of Katendrecht, Berke, P., Godschalk, D., & Kaiser, E., with D. 14(3), 895-908. Third National Climate Assessment, J. M. Rotterdam. Rodriguez. (2006). Urban land use planning Doucet, B., Van Kempen, R., & Van Weesep, Melillo, Terese (T.C.) Richmond, and G. W. (5th ed.). Urbana-Champaign, IL: Universityof J. (2011). Resident perceptions of flagship Yohe, Eds., U.S. Global Change Research Illinois Press. waterfront regeneration: the case of the Program, 579-618. doi:10.7930/J0MS3QNW. Berke, P., Newman G., Lee, J., Combs, T., Kop van Zuid in Rotterdam. Tijdschrift voor National Oceanic and Atmospheric Kolosna, C. & Salvesen, D. (2015). Evaluation economische en sociale geografie, 102(2), 1. Administration. (2015). Digital coast. of Networks of Plans and Vulnerability to Federal Emergency Management Agency National Research Council. (2012). Disaster Hazards and Climate Change: A Resilience [FEMA]. (2016). Disaster Mitigation Act of resilience: A national imperative. Washington, Scorecard, Journal of the American Planning 2000. DC: National Academies Press. Association, 81(4), 287-302 Flanagan, B., Gregory, E., Hallisey, E., Heitgerd, Patterson, L., & Doyle, M. (2009). Assessing Berke, P. R. (1996). Enhancing plan quality: J., & Lewis, B. (2011). A social vulnerability effectiveness of national flood policy through evaluating the role of state planning index for disaster management. Journal spatiotemporal monitoring of socioeconomic mandates for natural hazard mitigation. of Homeland Security and Emergency exposure. Journal of the American Water Journal of environmental planning and Management, 8(1), 1–22. Resources Association, 45(1), 237–252. Preliminary Findings: Network of Plans The remaining unembanked neighborhoods not been included in the preliminary analysis management, 39(1), 79-96. Hobma, F., & Schutte-Postma, E. (2010). Piantadosi, S., Byar, D. P., & Green, S. B. (1988). Response to Vulnerabilities – Feijenoord and the northern part of as it has yet to be finalized. Borger, G. J., & Ligtendag, W. A. (1998). The Planning and Development Law in the The ecological fallacy. American journal of When evaluated together, patterns in Afrikaanderwijk – are among the least role of water in the development of the Netherlands. Delft, the Netherlands: Delft epidemiology, 127(5), 893-904. vulnerability and plan scores across the physically vulnerable places in the From the patterns described above, it is Netherlands—a historical perspective. Journal University of Technology. Southeast Florida Regional Compact. (2012). Feijenoord District’s neighborhoods are district, though they are much more apparent that Feijenoord District’s network of Coastal Conservation, 4(2), 109-114. Intergovernmental Panel on Climate Change. Analysis of southeast Florida sea level rise. instructive regarding the spatial nature of socially vulnerable than the unembanked of plans is more likely to reduce vulnerability Brody, S. D. (2003). Are we learning to make (2014). Summary for policy makers. United Nations General Assembly. (2015). policy responses and integration of the neighborhoods discussed above. {More on in the embanked neighborhoods, which better plans? A longitudinal analysis of plan Jonkman, S. N., Kok, M., & Vrijling, J. K. United Nations world conference on disaster network of plans. social vulnerability will be added in the future, have relatively low physical vulnerability, quality associated with natural hazards. (2008). Flood risk assessment in the reduction—Sendai framework for disaster see below.} Their overall policy scores are and more focused on development in the Journal of Planning Education and Research, Netherlands: A case study for dike ring South reduction 2015–2030. Sendai, Japan: Author. • Network of Plans Response to Physical also relatively high (+9 and +13, respectively), highly physically vulnerable unembanked 23(2), 191-201. Holland. Risk Analysis, 28(5), 1357-1374. United States Census Bureau. (2016). Vulnerability thanks in large part to the Adaptation neighborhoods. {This section will be Burby, R. J., Beatley, T., Berke, P., Deyle, R., Kaufmann, M., Mees, H., Liefferink, D., & Retrieved from https://www.census.gov The four most physically vulnerable Strategy. In fact, Feijenoord’s land use plan expanded in the future.} French, S., Godschalk, D., Platt, R. H. (1999). Crabbé, A. (2016). A game of give and take: Van Alphen, J. (2015). The Delta Programme neighborhoods – Wilhelminapier, Kop van and water plan scores are both neutral, Unleashing the power of planning to create The introduction of multi-layer (water) safety and updated flood risk management policies Feijenoord, Noordereiland, and Katendrecht indicating that these plans are equally as Expectations for the Remainder of the Study disaster-resistant communities. Journal of the in the Netherlands and Flanders. Land Use in the Netherlands. Journal of Flood Risk – all border the Nieuwe Maas River in the focused on development as on reducing & Future Research Directions American Planning Association, 65(3), Policy, 57, 277-286. Management. DOI: 10.1111/jfr3.12183 unembanked part of Feijenoord District. vulnerability in the neighborhood. Following completion of the remaining Burby, R., May, P., Berke, P. R., Dalton, L. C., Klijn, F., van Buuren, M., & van Rooij, S. A. Van der Valk, A. (2002). The Dutch planning Current plan scores are relatively high (+9 analysis, this paper will be revised and French, S. P., & Kaiser, E. J. (1997). Making (2004). Flood-risk management strategies experience. Landscape and urban planning, to +14) for these vulnerable neighborhoods, Except for the large southern neighborhood expanded to include a more comprehensive governments plan. Johns Hopkins University for an uncertain future: living with Rhine 58(2), 201-210. except for Katendrecht, which has the of Vreewijk, which is moderately literature review, detailed analyses and Press, Baltimore. river floods in the Netherlands. AMBIO: A Vis, M., Klijn, F., De Bruijn, K. M., & Van Buuren, lowest overall policy score (+1), due in large vulnerable, physical vulnerability in the findings, a description of study limitations, Centraal Bureau voor de Statistiek. (2016). Journal of the Human Environment, 33(3), M. (2003). Resilience strategies for flood risk part to its land use plan which is strongly embanked neighborhoods is relatively low; and recommendations for future research. As Retrieved from http://statline.cbs.nl/Statweb/ 141-147. management in the Netherlands. International focused on development. Noordereiland’s Afrikaanderwijk, Bloemhof, and Hillesluis all in the United States, the results of this initial City of Rotterdam. (2013). Rotterdam Climate Macintosh, A. (2013). Coastal climate hazards journal of river basin management, 1(1), 33-40. land use plan score is also negative (-1) and have mean housing values below €100,000. ‘proof-of-concept’ may prompt investigations Change Adaptation Strategy. Rotterdam, the and urban planning: How planning responses Weetmeer. (2016). Buurtkompas. Retrieved its water plan score is neutral, but these are The embanked portion of Afrikaanderwijk of additional Dutch or European districts/ Netherlands. can lead to maladaptation. Mitigation and from http://www.weetmeer.nl/buurt/ balanced by the Rotterdam Climate Change receives the highest overall plan score (+18), cities/regions and comparative analyses Correljé, A., & Broekhans, B. (2015). Flood Adaptation to Global Change, 18(7), 1035– Ward, P. J., Pauw, W. P., Van Buuren, M. Adaptation Strategy, which contains many however, as a result of relatively high scores in using the Plan Integration for Resilience risk management in the Netherlands after 1055. W., & Marfai, M. A. (2013). Governance of policies designed to reduce vulnerability in all three of the plans in its network. Vreewijk’s Scorecard method. A mixed-methods the 1953 flood: a competition between the Mileti, D. (1999). Disasters by design: A flood risk management in a time of climate unembanked areas along the Nieuwe Maas. overall score is third highest in the Feijenoord approach, including more interviews with public value (s) of water. Journal of Flood reassessment of natural hazards in the United change: the cases of Jakarta and Rotterdam. All three of Kop van Feijenoord’s plan scores District (+13), also due to positive scores in practitioners and policy experts in the U.S. Risk Management, 8(2), 99-115. DOI: 10.1111/ States. Joseph Henry Press. Environmental Politics, 22(3), 518-536. are positive, giving it the second highest all three plans. Thus, plans that affect both of and the Netherlands may also be employed jfr3.12087 Ministry of Infrastructure and the Wesselink, A. J. (2007). Flood safety in the overall policy score (+14) in the district on the these neighborhoods indicate close alignment in the future to help illuminate the drivers de Moel, H., Bouwer, L. M., & Aerts, J. C. Environment. (2013). Spatial Planning Netherlands: the Dutch response to hurricane strength of a well-aligned network of plans. and a focus on vulnerability reduction. The of certain land use policies, obstacles (2014). Uncertainty and sensitivity of flood Calendar: 75 years of national spatial Katrina. Technology in Society, 29(2), 239-247. {The overall policy score for Wilhelminapier same can also be said, though to a lesser to implementation, and the implications risk calculations for a dike ring in the south policy in The Netherlands. Den Haag, the will likely be altered by its land use plan score, degree, about Bloemhof and Hillesluis of greater or lesser plan integration and of the Netherlands. Science of the Total Netherlands: Ministry of Infrastructure and 66 which has yet to be finalized.} {although the latter’s land use plan score has responsiveness. Environment, 473, 224-234. the Environment. 67 Example of a Randall Andress bioswale (Image courtesy Rotterdam Municipality). MITIGATING URBAN FLOODS THROUGH GREENING INITIATIVES

ROTTERDAM CITY

Randall is an undergraduate student at Texas Flooding is one of the fastest, most parking lots, driveways and sidewalks. The A&M University at Galveston. destructive, and costliest natural occurrences majority of green infrastructures contain on earth. Floods losses are expected to various weather tolerant species of native reach an estimated $1 trillion annually by vegetation. Areas impacted by urban The total human population is estimated the year 2050 (Flood Damage). In 2015, flooding that utilize greening systems, to be 7.4 billion and 40-45% of that resides Houston received a total of 70.03 inches of capture rainfall thus preventing stormwater within coastal regions (UN Atlas). The rain (National Weather Service). Between the runoff from overwhelming sewage networks coastal city of Rotterdam is home to roughly years of 1996-2015 there were 96 days with at and accumulation above impervious surfaces 630,000 people and with surrounding least one flood reported. That averages out to (EPA). This comparative study emphasizes metropolitan regions it reaches nearly 1.5 4-5 of flooding each year (Erdman). the utilization of green infrastructure in million. The city of Rotterdam is continuing Rotterdam as one solution to mitigate urban to grow with a current average rate of 0.61% Rotterdam is at the forefront of preparedness flooding in Houston. per year (Rotterdam Municipality). With for large scale coastal flooding and climate the increasing urbanization that Rotterdam change. A global rise in temperature is Bioswales is encountering, the city is becoming less intensifying already increased rainfall Bioswales are linear, vegetated, low lying permeable. Rapid urbanization of cities amounts. Mitigating such impacts is a containments spaces that intercept decreases the existing amount of green localized obstacle that will require climatic stormwater runoff from impervious surfaces spaces, in effect, increases the total amount specific solutions. The Netherlands is leading through their diverted trenches. They are of impervious surfaces. This process by example in their efforts to combat climate able to do this because of its swaled drainage produces more storm water runoff than change. With this research, there will be a course that has a typical 6% decline into the natural, undeveloped areas and stresses clearer understanding of what is needed ,on a containment space. This is an alternative to city infrastructure. Conventional stormwater larger and smaller scale, to reduce flooding in traditional storm sewers that can be found management systems are designed to metropolitan areas through implementation near areas of higher impermeability such quickly drain existing stormwater. When of green infrastructures. as roads, sidewalks, parking lots and office weather events occur that are too intense buildings (Bioswales, 2016). for stormwater management systems, it may Green areas result in what is called combined sewage Green areas, also referred to as green These multifunctional bioswales not only overflows (CSO’s). This process occurs when infrastructure, are a system of integrated delay the timing of peak runoff, but provide an overwhelming amount of stormwater landscapes that provide linkage between filtration of silts and pollutants through is drained into sewage systems, causing a urban development and nature. These are the vegetation and sediments it contains. portion of a system to become inefficient. multifunctional areas that provide many The soil infiltration rate of bioswales should benefits- creating a positive correlation be greater than 1.27 cm per hour (Bioswales). This is a primary issue that contributes between the amount of greening initiatives Generally, soils are not compacted during to flooding in the city of Houston, Texas. and the surrounding quality of life. The installation, as this would result in longer Houston, already the fourth largest city in city of Rotterdam, is seeing an increase absorption rates. the United States, is expected to gain 3.5 in its abundance of green infrastructure in million new residents in the Greater Houston locations where there is a higher vulnerability Native vegetation with deeper roots are ideal Area before 2030. If followed, this trend will for urbanized flooding. Although there are for exceptional infiltration and requires less result with the total population reaching an copious variations of green infrastructures, maintenance. After the water is filtered, it can estimated 10 million (The Conservation Fund). the vast majority can be utilized to then be infiltrated back into the groundwater As the city implements, expands and updates supplement stormwater management. supply. With the groundwater supply being their current infrastructure to accommodate Green areas have a lower central elevation replenished, vegetated bioswales can population growth , the same must be done for better containment and are typically alleviate Houston’s current drainage systems 68 with green infrastructures. located near highly paved surfaces such as during rainstorm events. 69 Example of a Perhaps one of the most attractive aspects is a company in the Netherlands that has These can be seen in Rotterdam as well green roof (Image of bioswales is their costs. The cost is greatly installed over 10,000 green roofing systems as Houston and are artificially designed, courtesy Rotterdam dictated by size, species of vegetation, since 2010 (Dakdokters). Dakdokters differs complex vegetated water bodies that can Municipality). location, but is especially less expensive than from other companies in that they have provide treatment of both wastewater the stormdrain alternative. developed a new containment system for the effluent and stormwater runoff. Retention roofs they install. This system is essentially a ponds and constructed wetlands collect Green Roofs collection of buckets at the very bottom of storm water runoff and retain it for longer Most roofs, with the consideration of a few, the roof, which allows for better stormwater periods of time. By these wetlands holding are among the most abundant of impervious management. The soil filtering layer is the runoff longer, it allows for contaminated surfaces (VanWoert et al). Stormwater directly above this. This layer serves as a stormwater to undergo biological interactions runoff from urban roofs makes a significant way to separate the water from the soil for to improve its quality. Retention ponds and contribution to urban flooding. An alternative sufficient drainage. The substrate layer has constructed wetlands typically require larger to traditional impermeable roofing is, green the ability to absorb rainwater and provides amounts of surface area in comparison to roofs. Green roofs are a type of low impact a foundation for the vegetation layer. All other types of green infrastructure. They are development (LID) that completely or elements of green roofs are commonly also substantially effective and efficient at partially cover a roof with vegetation and a placed over a waterproof membrane. preventing floods (Volder). growing medium to counteract the loss of green spaces (VanWoert et al). Green roofs Green roofs can decrease annual stormwater Methodology can be an attractive aspect to businesses, runoff by an average of 50-60%, this also The goal of this study was to compare homes and government facilities. The includes peak runoff. Vegetated roofs control the differences in green infrastructure in design and purpose of these roofs may vary between 30-90% of the volume and rate of Rotterdam and Houston. From research, there depending on location. stormwater runoff, detaining 90% of volume would be a better understanding of what for storms less than one inch and at least types of greening infrastructures would be These roofs are classified into two categories, 30% for larger storms (Foster). Intensive most suitable for Houston. This was done by intensive and extensive. Intensive roofs, are roofs are approximately twice as good at first reviewing literature specific to the history typically larger with a minimum depth of 12.8 runoff management as extensive roofs. and climate of Rotterdam, Netherlands. cm. Intensive roofs can be the foundation for During the summer months, depending on Literature review was continued with topics vast diversity of vegetation, but their weight the vegetation and their growth rates, green pertaining to urban flooding caused by can be substantial and require a considerable roofs retain 70%-90% of the precipitation impervious surfaces, effects of urbanization amount of maintenance. The second category, that falls on them (About Green Roofs). This on stormwater management, and mitigating extensive roofs, are more shallow with depths is a technology that is plentiful through The floods with nature. ranging from 2 cm to 12.7 cm (Dolman). Netherlands and although it could be very These are are typically used for aesthetic beneficial, it is rarely seen in Houston. The next course of study was researching appearance. Extensive roofs are much lighter experts in the Netherlands that have worked than intensive therefore smaller plants and Detention ponds and dry basins in the related fields. During research I had grasses are ideal for this type of roof. Green Another concept that is already widely used conducted multiple meetings with experts roofs can reduce annual stormwater runoff in the Houston area is detention ponds and the first being, Friso Vos de Wael who is an by 50-60% on average, including peak runoff. dry basins. These are depressed areas of innovative agent and start up coordinator Vegetated roofs control between 30-90% of earth that are typically dry and temporarily with VP Delta. His role in the organization the volume and rate of stormwater runoff, store rainwater and release it at a controlled is to help manage and facilitate those with detaining 90% of volume for storms less than rate. These ponds are often referred to as innovative flood defense technologies. From one inch and at least 30% for larger storms. Best Management Practices (BMP’s), used this meeting I was able to attend Flood Intensive roofs are approximately twice as to manage excess urban runoff. Detention Proof Holland where a variation of theses good at runoff management as extensive ponds and basins can range in a large innovative technologies were demonstrated roofs.While green roofs differ depending on variety of sizes and depths. Since these are in controlled testing ponds. Mr. Vos de Wael location, the majority of their layers remain man made detention areas, they are usually provided me with an abundance of literature, the same (Green Roof Benefits). constructed along with new development companies and experts to research. to offset the increasing impervious surfaces. A typical green roof consists of four layers- This is an efficient way to capture and store a Another expert that was interviewed drainage material, soil filtering layer for large volume of stormwater especially during named, Peter Van Veelen is member of the the passing of water, substrate layer and a flash flooding. faculty of Urban Design at TU Delft and vegetation layer. The bottom layer contains a has worked on adaptive planning with the drainage system that allows for excess water A similar concept like detention ponds and city of Rotterdam for over 8 years. Mr. Van 70 to escape. The Dakdokters, or Roof Doctors, basins is constructing artificial wetlands. Veelen was a contributor to the Climate 71 Rotterdam climate Proof Rotterdam adaptive strategy. During Because Houston has a deeper water table Dakdokters. “Our Mission.” . N.p., 2016. Web. 6 adaptation this meeting, Mr. Van Veelen was able to level that averages 3.05m-9m, bioswales June 2016 strategies, including Green roofs answer many questions and uncertainties. Mr. have capability of performing very well in its Environmental Protection Agency “Manage greening initiatives VanVeelen also provided several contacts in highly impervious areas (Noble et al). These Flood Risk.” EPA. n.d. Web. 17 Aug. 2016. (Image courtesy The Netherlands. could be installed along the developing and Erdman, Jon. “Is Houston America’s Flood Rotterdam pre existing sidewalks, roads and parking lots Capital?” The Weather Channel. N.p., 19 Apr. Municipality). Water storage / smart reuse The last expert that was interviewed was within Houston. 2016. Web. 1 Aug. 2016. Nanco Dolman, an engineer with Royal Foster, Josh; Ashley Lowe; Steve Winkelman; Haskoning DHV. Mr. Dolman was most From this research it was concluded and Helps. Policymakers Around The World Green facades and blue roofs informative with any and all questions. He that green roofs are efficient in retaining To Develop, Promote And Implement provided a wealth of literature and his own stormwater in lighter rain events, but quickly Innovative,. “The Value of Green Infrastructure personal works. The final step of researching become saturated during the intensified for Urban Climate Adaptation.” n. pag. Web. was extensive review of all literature provided events. Mr. Dolman explained that green 12 July 2017. for this study and compare to literature roofs would be much more effective on a GRHC “Green Roof Benefits - GRHC pertaining to Houston. larger scale. If our government provided more WEBSITE.” . N.p., n.d. Web. 1 Aug. 2016. incentives and assistance for the installation Houston Population. (2016, August 06). Findings of green roofs such as Germany has done, Retrieved August 10th, 2016 Prior to meeting with Peter Van Veelen, it there would most likely be an increase in Natural Resource Conservation Service, was obvious that the Dutch had spent much installation. “Bioswales...Absorb and Transport Large of history trying to keep water out, but it Runoff Events.” Bioswales (n.d.): n. pag. 2005. was unclear exactly how much they are Not only do green roofs provide stormwater Web. 24 May 2016 embracing it today. By Rotterdam taking management capabilities, but they also offer NOAA “National Weather Service Weather advantage of the amount of water they have, many other ecological benefits as well. Green Forecast Office.”Climate_iah_normals_ they are now being referred to as a Sponge roofs actually act as insulators, retaining heat summary. , n.d. Web. 1 Aug. 2016. City. Mr. Van Veelen described Rotterdam during winter and keeping in air conditioning Noble, J.E., P.W. Bush, M.C. Kasmarek, and as a front runner of flood prevention with during summer. This in return also saves D.L. Barbie. “ESTIMATED DEPTH TO THE this statement “This whole system functions owners on their electricity expenses. Another WATER TABLE AND ESTIMATED RATE OF perfectly, there is almost no fluvial flooding, benefit of these roofs is their ability to RECHARGE IN OUTCROPS OF THE CHICOT so the system is quite well managed. It is increase air quality and reduce the urban AND EVANGELINE AQUIFERS NEAR also very complex.” It is clear that the city of heat island effect. HOUSTON, TEXAS.” USGS Water-Resources Rotterdam, looks at water as an opportunity Investigations Report 96-4018 (n.d.): n. pag. not a burden. He expressed his concerns for From this study, I learned that green U.S. Geological Survey. Web. 27 June 2016. how challenging it is to identify the areas infrastructure would be great first responder Rotterdam Municipality. “Zuid-Holland.” N.p., that are most at risk. The risk assessments for for retaining stormwater as long as possible. n.d. Web. 13 Apr. 2016. this type of flooding are still in the beginning This in return would slow runoff to other “UN Atlas: 44 Percent of Us Live in Coastal stages of development due to the need for areas. This would offset our conventional Areas.” Coastal Challenges Com. N.p., 31 Jan. such small scale measures in a very large stormwater management systems from 2010. Web. 16 Aug. 2016. area. As a result of most development being functioning inefficiently during intensified VanWoert et al. “Green Roof Stormwater water robust infrastructure very compact, there is a spatial challenge weather events. This study gave me a new Retention: Effects of Roof Surface, Slope, /’bioswales’ for Rotterdam to implement greening interest in how cities and government and Media Depth.” Journal of Environmental infrastructures. Perhaps the most effective implement such infrastructures. For Quality (2005): n. pag. National Center for Multifunctional way of resolving this issue is through prospective research projects, I will most Biotechnology Information. U.S. National flood defenses public awareness. Property owners can definitely use the information and knowledge Library of Medicine, 11 May 2005. Web. 29 use these greening initiatives to increases present in this paper as well as what is not. May 2016. URL: (http://www.ncbi.nlm.nih.gov/ attractiveness, property value and quality of pubmed/15888889) life, while reducing the amount of runoff. Volder, Astrid; Dvorak (February 2014). References “Event size, substrate water content and Most of the elevations in the Netherlands “About Green Roofs.” N.p., n.d. Web. 16 Apr. vegetation affect storm water retention are below sea level and have a water table 2016. efficiency of an un-irrigated extensive green depth of nearly 0.2 m below the surface “Bioswales.” Bioswales. N.p., n.d. Web. 2 Aug. roof system in Central Texas”. Sustainable (Veelen). These are not ideal conditions for 2016. Cities and Society 10: 59–64. doi:10.1016/j. swales due to the fact that swales store The Conservation Fund. “Ecosystem Services scs.2013.05.005. water underground where the watertable for Houston-Galveston | The Conservation Veelen, Peter Van. “Interview with Peter Van 72 is shallow and plentiful in The Netherlands. Fund.” N.p., n.d. Web. 01 Aug. 2016. Veelen.” Personal interview. 30 May 2016. 73 Figure 5. (below) right showing the Figure 7. (below) Figure 8. (below) Ramatullah Faizi The monument basalt revetment Seaside slope Seaside slope location at the near the statue. viewing South of viewing North of middle On the Afsluitdijk Afsluitdijk. THE AFSLUITDIJK - ALTERNATIVE DESIGN FY2100 top left the blue structure showing the history of the Afsluitdijk. On the LAKE IJSSEL

Ramatullah is a MSc student at Jackson State design storm of 1: 10,000 years. According - Wave run-up and run-down are defined as University, Mississippi. to a previous study done by a consultant, the extreme levels that a wave can reach the significant concern is the overtopping. on a sloping structure. This overtopping causing erosion of the inner - Wave overtopping occurs when wave run- The Netherlands means lower countries, slope which results to the failure of the dike. up exceeds the crest level. which describes its lowland, flat geography Thus, the main objective of this research is - Wave transmission occurs when a and most of its parts being under sea level. to evaluate different types of Armor Unit to structure has a permeable core, which With a population density of 501 people per prevent overtopping. permits the transmission of part of the sq. km, a flood of the land would threaten wave energy through the structure. many lives of people who live near the coast. Wave Interaction - Wave reflection is when part of the wave Because of this and the learned lesson from The interaction between waves and hydraulic energy returns towards the sea because of the historical flooding the Dutch government structures can be classified into; wave run-up the iInfluence of a hydraulic structure. has been taking this concern very seriously. (and run down), wave overtopping, wave Figure 2. (below) Figure 4. (right) Figure 6. (right They have created many different programs transmission and wave reflection according Two different types of overtopping are Overview of the The Monument middle) and projects for flood protection. One of the to CIRIA et al (2007). distinguished: four different location looking The Monument projects that they revealed on 12 May 2015 - ‘Green water’, which is related to complete water sections: south of the location at the was a reinforcement of 32 km long closure sheets of water that run over the crest of a Noordzee, Wadden Aflsuitdijk. tourist bridge and dam, the Afsluitdijk. defense. Zee, IJsselmeer, the elevated tower. - ‘White water’, which is related to waves Markermeer. The Afsluitdijk is a dike and a major that break at the seaside, generating causeway and water management location an important amount of spray and a non-c in the Netherlands, proposed by Dr. Ing. ontinuous overtopping flow. Cornelis Lely after the flooding of 1916. It Spray generated by the wind can generate was constructed between 1927 and 1933 some hazards for people and vehicles near and running from Den Oever on Wieringen the dike, due to lack of visibility. in North Holland province, to the village of Zurich in Friesland province. It has a length Data Collection of 32 km (20 miles) and a width of 90 m. It In May 2016, the NSF-PIRE group visited the also has a dike crest height of 7.25 m above Afsluitdijk, one of the major structural flood sea-level. risk reduction measures in The Netherlands. It is located in the Northeast of the Netherlands This dike’s seaside slope has been protecting and it divides the Ijsselmeer at the South East the Netherlands for 80 years. However, with from the Waddenzee and the Wadden Islands the current climate change that is causing at the North West (Figure 2). sea level rises and higher flood safety standard this dike has to be reconstructed. The following was observed at the site: The Dutch government is evaluating different a. At the ‘Monument’ location, there were options to solve this concern. The final design several objects found. These include the has to meet the safety standards of 1:10,000 statue of Dr. Ing. Cornelis Lely, information years and 10 l/s/m. Definitions for each interaction process are: wall, Bridge for the pedestrian, a statue of the - Wave conditions are defined by incident worker, building with tower and restaurant With the sea level rising and an increase wave height (usually significant wave (Figure 4-6). in storm intensity, the existing design of height), the wave period, the angle of b. The seaside does not have any rip raps 74 Afsluitdijk is not sufficient to withstand the incidence and the local depth. while on the lake side, the toe has rip rap 75 Table 1. (Figure 6 & 8). Design Criteria Analysis: Decision matrix outward will be refused by the European Dike section with its c. Seaside and lakeside have basalt with grass In this section, each design is evaluated environmentalist along with the Natura 2000 length. Stan Veraat on the upper part of the slope (Figure 7 & 8). using their level of performance and program. For example, most of the mussels’ (2014). d. The crest of the dike serves as a parking relative importance. To do this, a Multi- habitat is at the foot of the of Afsluitdijk. area for vehicles and the bike route has a Criteria Analysis was chosen because of its With an extension, mussel habitat will be transition from inner highway side slope to simplicity and standardized mode for scoring eliminated and will likely take at least 15 years outer seaside side slope (Figure 5). alternatives with key differentiators to avoid of growing back. This subject was brought up e. Beside the monument location, the crest subjectivity. In Table 3 the five different and discussed during the build with Nature is an average of 2 meters in width that is criteria are described. workshop in Delft University. covered in clay and grass. Alternative dike design Alternative Overtopping design Typical Cross section of the dike There are three design ideas behind the From 5.1 section the best alternative to The core of the dike has boulder clay. On modification of Afsluitdijk. Each design is achieve all of the requirements is to extend top and on the side of this bolder clay core listed in order of best choice. the monument section throughout the Table 2. sand is placed. The dike body is covered with dike. With this selection, the next step is to Wave climate data rubble, a stone revetment and a clay cover Extension of the monument section select an armor unit that will decrease the for Afsluitdijk at with grass. The shape of the dike body is This alternative is focused on keeping the overtopping discharge to less than 10 l/s/m. five different cross almost the same along the Afsluitdijk. From design of the monument’s cross section but With the stability of armor units in mind, sections. the client and a previous study, this dike has increase the height of the crest and steepen five armor unit are chosen; Core Loc, Xbloc, been separated into 17 different sections. For the slope. The outer slope revetment consists Samoa stone, Cubes and Rip rap (Figures see this report, only 7 major cross-sections and of concrete armor units which will reduce page 80).PC-over-slag software was used the length is given in Table 1 and Figures 9-15. the overtopping discharge to an order of 10 to find the run-up and overtopping rate. To l/s/m. This design will also provide a strong make an accurate comparison between all Wave Climate protection against the high wave impact of five armor unit,s only one slope was The wave climate having a 10,000 years of waves that a significant wave height chosen 1:2. return period was given by the client for (Hx = 3.5 m/s with a 1/10,000 per year seventeen different cross section. The available probability). The bike path is to be rerouted Core Loc information includes mean sea level elevation, at the top of the crest along the seaside The Core-loc concrete armor unit which is significant wave height, mean wave period throughout the dike. The current crest height patented by the United States Army Corps Table 3. and peak period. For this design purposes, the at the monument is 7.85 m and 13.8 m wide. of Engineers represents one of the latest Design criteria. end of the structure service life is considered With this proposal, the monument section technology in armor units. The new unit has at 2100. Please note the wave climate data width will stay at 13.8 m. After and before been used in coastal breakwater structures includes a 10% factory of safety and due to its the monument section the width should be since 1996. The armor unit was developed low magnitude, within the scope of this report decreased to 6 m. This will be enough for the to produce an efficient use of concrete with and studies, currents are neglected. bike route, possible marathon events, and sufficient strength and robustness to achieve even tourists to walk the whole length of the a cost-effective, highly stable structure. This Problem analysis: Overtopping Afsluitdijk. The height with a conservative was discussed with the inventor of the Core The overtopping rates and maximum wave design approach will have to be increased by Loc, Dr. Jeffrey Melby. Core Loc armor units overtopping volume are calculated by 2.0 m at an overall height of 9.85 m + NAP. have the highest ranked stability testing using computer program PC-Overslag, HR according to the Army Core of Engineers, Wallingford Ltd. UK. The storm duration is Invading lake IJssel George T. Jeffery M. (1997). The armor unit assumed to be 12hr, and the incident wave This alternative is to extend the dike toward size came to be 2.8t and a height of 1.41m. Table 4. angles are considered to be 0 in order to Lake Ijssel. With this design, the road and The Xbloc under layer is supported by rocks Final discussion obtain a conservative result for this design. bike route will have to be relocated 6 meters between 280kg-750kg. matrix. On Figure 16 the results show the output of toward Lake Ijssel. The relocating will be very PC-Overslag. Several important parameters costly thus this option is not feasible. Xbloc like wave run- up, mean wave overtopping The Xbloc armor unit was designed by Delta rates and maximum wave overtopping volume Invading the Waddenzee Marine Consultants in The Netherlands. It are selected. Because of the existing basalt, The purpose of this alternative was to keep has been used throughout the world and Figure 7 and 8, having a smooth surface the existing freeway and bike route intact. is known for its robustness. Xbloc armor the coefficient for the reduction factor was Only extend the dike toward Waddenzee unit has the second most advantage in chosen to be smooth impermeable surface. with steeper slope and height. The concern stability design as well as this armor unit The total overtopping of current condition is with this design is that Waddenzee is a being developed in The Netherlands. With 76 513.7 l/s/m. protected ecological zone. Any extension its interlocking blocks, one layer can achieve 77 78 79 Figure 20. (left) overtopping discharge rate of 1.301 l/s/m. For First of all, from the results in Table 4, References Core-loc breakwaters the 1:2 slope, the armor unit size came to be It is concluded that a higher dike crest Ciria, Cur, & Cetmef. (2007). The rock manual: at Port St Francis, 3t and a height of 1.64m. The Xbloc under has a major influence on lowering of the the use of rock in hydraulic engineering (2nd South Africa. layer is supported by rocks between 400kg- probability of failure. Therefore, a higher edition ed.). London: C683,CIRIA. 800kg. dike crest is recommended to decrease Dean, R.G., J.D. Rosati, T.L. Walton, and B.L. Figure 21. (right) the overtopping rate to 10l/s/m. One of the Pullen, T., N.W.H. Allsop, T. Bruce, A. Overtopping rate Samoa Stone desires for the design of the Afsluitdijk is that Kortenhaus, H. Schüttrumpf, J.W. Van der with Core Loc. Samoa stone is another type of armor unit it has uniform design along the complete Meer, et al. EurOtop; wave overtopping of sea patented by the United States Army Corps body of the dike as seen on Figures 9-15. defenses and related structures - assessment of Engineers. Its advantage is the being the Some dimensions vary but with a strong manual. UK: NWH, 2007. ISBN 978-3-8042- aesthetically best looking among this group and reusable core it should be stable 1064-6. URL www.overtopping-manual. Figure 22. (left) and has a very strong interlocking. Because enough from the geotechnical standpoint. com/manual.html. Delfts Hydraulics. The Shore protection Samoa stone are new armor units, these were Additionally, the followings are the findings Netherlands. with Xbloc at Cinta not listed on the PC Over-slag to check its and recommendations: PC Over-slag, HR Wallingford Lt . UK. URL Costera, Panama. overtopping discharge. Using Hudson formula, - The best alternative design for the dike http://www.overtopping-manual.com/ the discharge came to be 5.34 l/s/m. The cross section would be the extension of EmpArmourSlope_CompositeWall.aspx Figure 23. (right) weight of armor units came to be 2.9t with an the Monument section throughout the Edge. Erosional equivalences of levees: Overtopping rate under layer of 252kg-500kg. Afsluitdijk. The bike path will have to Steady and intermittent wave overtopping. with CXbloc. be re-routed on top of the crest to the ocean engineering, 37(1), 2010. Concrete Cubes Waddenzee side. The crest width shouldn’t URL www.sciencedirect.com/science/article/ In The Netherlands, Cubes have been one be more than 6 m. The height increase is pii/S0029801809001796. of the main armor units used beside Rip recommended to be 2 m higher than the George T., Jeffery M. (1997). Core-Loc Figure 24. (left) Rap. The picture below shows Port of existing height of 7.85m. This height is Concrete Armor units: Technical Guidelines. Example of Samoa Scheveningen, NL. The preliminary calculation sufficient for the thickness of the armor unit Vicksburg, MS. Stone. Because for concrete cube results in a size of 2.7t. and selected. Gerding, E. (1993). Toe structure stability of Samoa stone are an under layer with rocks of 600kg-700kg. - Core Loc had the most points in all five rubble mound breakwaters. Master thesis, TU new armor units, The cubes have been used throughout The criteria relative to other armor units. Delft, Delft. these were not Netherlands. Using the cubes will preserve the - The design intent of the chosen armor unit Hudson, R.Y. (1974) Concrete Armor Units for listed on the PC for historical aesthetics. was to keep the existing basalt to minimize Protection Against Wave Attack. U.S Army overtopping rates. cost and add the chosen armor units on the Engineer Waterways Experience Station. Rip rap top. Hydraulic Laboratory. Vicksburg, MS. Rip rap or stone armor are the most - The berm at the end of the dike width Pablo A., Yuting L., Maria F., Carlos E. (2013). common type of armor unit because of it’s should be the same as the existing cross Afsluitdijk upgrading non-typical Dutch Figure 25. (left) economical, and hydraulically efficient method section at 5.5m. solutions. Master thesis, TU Delft, Delft. Concrete Cubes of protecting rubble mound breakwaters, - A gravel filter layer with 150kg to 300kg is Van den Akker, P. (2014). The impact of a on the breakwater seawalls or revetments, and the upstream face recommended for the berm to have a better breach in the Afsluitdijk on the probability of at Port of of dams, from wave action. They can be found transition from stability standpoint from the failure of Ijsselmeer Dikes. TU Delft, Delft. Scheveningen, NL. naturally in many areas or can be man-made. seabed to the berm. Van der Meer, J.W. (1987). Stability of For the Rip rap selection, this design considers - The cost was not included in this design due Breakwater Armor layers – Design Formulae. Figure 26. (right) a typical breakwater with a slope of 1:2. For this to limited resources. However, we assume Veraat, S. (2014) Probabilistic design of the Overtopping rate preliminary design run-up and overtopping cost criteria will result in Xbloc being the renovation of the Afsluitdijk. Master thesis, TU with Concrete Cubes. was computed using the software PC Over- winner because of its construction process Delft, Delft. slag. For the armor unit size, the calculation being in The Netherlands. However, the Core was done using Hudson’s formula. The armor Loc patent will expire before construction Figure 28. (left) unit size came to be 1.7m and W=1.3t. so royalty costs will not factor into the Example of rip rap at overall cost. the Afsluitdijk facing Final Judgement - Further study and model testing is needed Lake IJssel. As discussed in section 4 the five criteria are to validate each armor unit size and shown in Table 4 (previous pages) with each overtopping discharge rate since this was a Figure 29. (right) armor unit’s total score. preliminary design. Overtopping rate - A geotechnical study should be conducted with rip rap. Conclusion and recommendation to make sure the existing bolder clay has Taking the results of the optimization into sufficient capacity to hold the new load of 80 account, an optimal design is recommended. armor units. 81 Figure 1. the water. The Fatimata Diop On the left: Water measurements are level measuring transferred to a station in IJmuiden. central database. STATISTICAL ANALYSIS OF EXTREME COASTAL WATER On the right: The (Photo’s by Jacob gauge of this station Venker) LEVELS IN THE NETHERLANDS where, under the black lid in a well, a float floats on

Fatima is a PhD candidate at Jackson State the components of these hydraulic boundary threshold method was used to obtain University, Mississippi. conditions (Caires, 2011). The determination partial duration series before fitting the of extreme water levels in a statistical context different datasets with a Generalized Pareto are necessary for the design/control of water Distribution. The Netherlands is densely populated and defenses and the mapping of flood risk areas. large parts of its territory are located below Background sea level. Safety is not only a major concern In practice, the probability of extreme water Extreme Value Theory (EVT) describe models but also a political matter as the chance of levels is estimated through the application of used to quantify rare and extreme events human loss and economic damage is high extreme value theory to measurements. The (maximum or minimum) in a statistical in the event of disasters. On February 1rst results of such analysis depend greatly on the framework. In general, there are two different 1953, a great North Sea storm surge on a high quality and length of records of the dataset ways to identify extreme events statistically. spring tide resulted in a massive flooding used. In the Netherlands, return values of up The first type consists of the maximum that caused by 67 dike breaches. The extensive to 1/10000 years are used, while the water the data takes within successive periods damages caused by the major flood of 1953 levels records vary between 50 to 100 years. (annual, monthly, seasonal even daily). Those prompted numerous studies to assess flood Although the extreme value analysis of selected maxima are called block maximum risk for the Netherlands coastal areas. The historical observations should be considered series (BMS). The second type consists of disaster claimed 1835 victims and caused a a first order approach, it is still necessary as it selected excesses over some high threshold total damage of about 0.7 billion Euro. set the benchmarks in the modeling of storm yielding partial duration series (PDS). These characteristics. two types of sample are attached to two The Netherlands invested tremendously extreme value distributions: the Generalized in their flood defenses to attain an ideal Study objective Extreme Value Distribution (GEV), fitted level of safety against flooding. The Dutch Storm surges are an important component of to the annual maxima and the Generalized flood defense strategy focused on flood extreme sea level. The study of its occurrence Pareto Distribution (GPD), fitted to peaks- prevention/control and is composed of a over time is indispensable as surge is over-threshold (POT) data for a sufficient large network of flood structures such as combined with tides and other factors to high threshold. dikes, dunes and dams. Evaluating high water determine extreme water levels. This study is level frequencies was necessary to estimate an attempt to show how the surge variable Distribution of Block Maximum Series

flood risk and maintain a certain level of should be defined while performing an Let Mn= max{X1,…,Xn } and X1,…,Xn be a safety. The standards for flood protection in extremal analysis of historical water levels. A sequence of independent and identically the Netherlands has been revised to reflect a statistical analysis of extreme water levels for distributed (iid) random variables with a complete failure probability. 8 locations along the Dutch Coastline was cumulative distribution function F.

conducted to estimate annual exceedance For σn>0, μn, ξn R, and some non-degenerate In addition to the previous design criteria probability or average recurrence interval cumulative distribution function G such that based on overtopping and overflow, the using two definitions of the surge variable Pr{M_n≤z}=G (z), G belongs to the generalized stability of the flood defenses are now taken at each location: (1) residuals computed as extreme value family of distributions. into consideration in the risk computations. the difference between de-trended observed Nevertheless, in compliance with the Flood water levels and predicted water levels and G(z) = exp {-[1+ξ((z-μ)/σ)]^(-1⁄ξ)} Defences Act of The Netherlands (“Wet op (2) skew surges, the difference between the de Waterkering, 1996”), the primary coastal predicted astronomical high tide and nearest The GEV family has three parameters, μ the structures must be examined every five observed high water. Different parametric location parameter, σ the scale parameter years for the required level of protection extreme value distributions can be used and ξ the shape parameter. The GEV family on the basis of the Hydraulic Boundary to estimate the probability of exceedance includes three types of distributions: the Conditions and the Safety Assessment of extreme values for water levels, for the Gumbel type distribution whose upper tail 82 Regulation. Extreme water levels are one of purpose of this study, the peaks-over- is infinite (light tail ξ=0), the Frechet type 83 Figure 1. distribution with an infinite upper tail (heavy and the Scheldt. The coastline is 451 km Non tidal residuals vs skew surges GEV distributions. tail ξ>0), and the Weibull-type distribution long, 65% of the coast consists of dunes and In this study, the POT-GPD method is with a finite upper tail (bounded upper tail 15% of the coast is protected by structures. applied to two datasets. The storm residuals ξ<0). Coastal and fluvial floods always threaten that constitute of the remainder after the The shape of the probability density the Netherlands. The effects of waves, storm astronomical tide component has been functions for the standard Frechet, Weibull surge and rainfall mainly cause coastal removed from the observed water level; and and Gumbel distributions is given in Figure 1. flooding. The wave climate is dominated by the skew surges computed as the difference The use of BMS renders large uncertainties in sea waves with a mean annual significant between the predicted astronomical high tide the resultant distribution as relevant extreme offshore wave height of about 1.1m. The and nearest observed high water within a events are lost in the use annual maxima. storm winds causing the largest wind set-up tidal cycle. On one hand, it is recognized that along the coast are coming from northwest residuals include primarily the meteorological Distribution Partial Duration Series (Van Rijn et al., 2002). The mean tidal range contribution to sea level along with processes The threshold approach consists of fitting varied from 1.40m to 3.30m making tides a other than storm surge. On the other hand, partial duration series obtained from a peak significant factor in the total water level. the skew surge parameter is regarded as over threshold method to a generalized a more reliable indicator of meteorological Figure 2. pareto distribution. This study is based on 8 observations impacts on sea level than residuals. It is GPD distributions. stations along the Dutch coastline. Among assumed that the skew surge does not

(σ.= 1) Let Fu(y) be a sequence of independent those stations, 5 have 100+ years of records, contain harmonic predictions errors, timing and identically distributed variables selected 1 station has 75+ years of records and 1 errors and non-linear residuals. from a POT method. It is assumed that station has less than 30 years of records

the excesses Fu(y) over the threshold u (PSMSL, 2016). The study area is shown in Figure 4. Non tidal residuals and skew surge follow a Poisson distribution with a rate λ. the figure below. Three hours water levels representation.

The distribution of Fu(y) conditionally on data was obtained for these stations from exceeding the threshold u is given by the Rijkswaterstaat. generalized pareto distribution Table 1. Water level stations and attributes

where y>0, σ is the scale parameter and ξ Figure 3. Table 2. the shape parameter. The GPD also has three Study Area; including types of tail behavior (see Figure 2), the beta the water level distribution when ξ<0 bounded above at measuring stations threshold –σ ⁄ ξ, the exponential distribution along the North Sea when ξ=0 and the Pareto distribution. coast mentioned in Methodology this paper. The GEV does not make efficient use of the The extremal statistics for water levels in this Figure 5. Historical records at Hoek van available data and its estimates have great study were computed using the StormSim Holland station. variability. The GPD method is considered software. StormSim is an extremal statistical Table 2. (far right, superior to the GEV as its results are based analysis and storm simulation software top) on bigger sample sizes. For this reason, system. StormSim consist of an integrated Parameter estimates the threshold approach (POT-GPD) is the framework of Matlab scripts developed POT-GPD with non- method of choice in this study. Different for statistical analysis of coastal storm tidal scales. Table 3. methods can be used to estimate the parameters and coastal storm responses. parameters of the GPD amongst which can StormSim have been used on a number Table 3. (far right, be cited the methods of moments, the least of previous studies (Nadal-Caraballo et al. bottom). square method and the maximum likelihood 2012; Melby et al. 2012). Individual StormSim Parameter estimates method (MLM). The MLM, which tends to routines for analyzing time series, computing POT-GPD with skew be the preferred method to estimate GPD extremal distributions, and plotting results surges. parameters, is used in this study. have been distributed for various Federal Emergency Management Agency (FEMA) Study area Risk Mapping, Assessment and Planning (Risk The Netherlands is situated at the North MAP) studies. 84 Sea in the deltas of the rivers Rhine, Meuse 85 Figure 6. Table 4. Extremal analysis of historical water levels Conclusion References The 1953 storm event Non tidal residuals As mentioned before, the data used in this Storm surges are a significant hazard to coastal Ministry of Transport, Public Works and at Hoek van Holland vs skew surges. study has already been processed adjusted to areas. This study shows that the skew surges Water Management (V&W), Directorate- station. NAP datum. The water level time series were for most return periods are smaller than the General of Public Works and Water de-trended by using a linear regression. The non-tidal residuals. The choice of the non-tidal Management 2002. Towards an Integrated detrended series were then adjusted to present residuals as surge component is reasonable Coastal Zone Policy: Policy Agenda for the day conditions by adding the difference from an arithmetic point of view. Taking the Coast. between the mean of the last 3 years of record difference between the observed water levels Coles, S. 2001. An introduction to the National Amsterdam Peil (NAP) and present and tides is correct but it can be misleading statistical modeling of extreme values. day NAP. Figure 5 shows an example of water if one wishes to quantify sea level change Springer Texts in Statistics. London: Springer- level records from Hoek van Holland station. due to genuine meteorological drivers. The Verlag. The extreme value analysis approach in this non-tidal residuals can contain artifacts of Caires, S., 2011. Extreme Value Analysis: study is outlined below: the subtraction between the observed water Still Water Level. Geneva, Switzerland: 1. De-trend water level series using linear levels and the tidal predictions such as a phase World Meteorological Organization, Figure 7, 8 ,9. regression and adjust data to present shift. The uncertainty associated with the skew Intergovernmental Oceanographic (left to right). day conditions. surges is also reduced compared to the non- Commission (of UNESCO), JCOMM Technical AEP plot POT-GPD 2. Separate the tide from the water level tidal residuals. Both surge definitions do not Report No. 58 surge: Delfzijl station observations. affect the detection of storms; however, the Davison, A. C., and R. L. Smith. 1990. Models (fig 7); Hoek van 3. Compute surge variables (residuals and skew surge method only provides information for exceedances over high thresholds (with Holland station (fig skew surges) for each station. about the maximum surge, and it seems to be a discussion). Journal of the Royal Statistical 8); West Terschelling 4. Perform peaks-over-threshold (POT) simpler. If the evolution of the storm surge with Society Series B 52: 393–442. station (fig 9). technique to sample a given number of time is of interest, non-tidal residuals should Dixon, M. J., J.A. Tawn and J.M. Vassie, 1998. events per year (λ) from both residuals and be used as surge component as it captures the Spatial modelling of extreme sea levels. skew surges. variation of the storm surge over time. Environmetrics. 5. Use Generalized Pareto Distribution (GPD) Hosking, J.R.M. and J.R. Wallis, 1987. and the Maximum Likelihood Method In closing, what is of the utmost importance Parameter and quantile estimation for (MLM) to fit the extreme water level is the ability to accurately estimate the the Generalized Pareto Distribution. empirical data to parametric distributions total water level for design and forecasting Technometrics. Figure 10, 11, 12. and compute return levels. purposes. When doing a statistical analysis Melby, J.A.,Nadal-Caraballo, N.C., Paga´n- (left to right). 6. Use bootstrapping to randomly sample of historical water levels, the climatology Albelo, Y., and Ebersole, B.A., 2012. Wave AEP plot, POT-GPD from GPD and extend the record length of the area of interest should be taken in Height and Water Level Variability on skew surge: Delfzijl 7. Determine mean probability distribution consideration and dictate the choice of the Lakes Michigan and St. Clair. Vicksburg, station (fig 10); curve and 95% confidence interval (upper surge variable. One necessary step in the Mississippi: U.S. Army Engineer Research and Hoek van Holland bound and lower bound). analysis should be to define the correlation Development Center, ERDC/CHL TR-12-23 station (fig 11); West between the tide and surge. In areas where Nadal-Caraballo, N.C., Melby, J.A. 2014. Terschelling station Extreme value analysis Results the tides and observed water levels may be North Atlantic Coast Comprehensive Study (fig 12). Residuals Results correlated, the non-tidal residuals should not Phase I: Statistical Analysis of Historical The model parameter estimates for all be used as surge variable. In regions with high Extreme Water Levels with Sea Level Change. stations are presented in Table 2. The tide range such as the Netherlands, the skew Vicksburg, Mississippi: U.S. Army Engineer Annual Exceedance Probability plots of the surge method is more appropriate than the Research and Development Center, ERDC/ corresponding GPD best fit for Delfzijl, Hoek non-tidal residuals. In the Gulf of Mexico for CHL TR-14-7 van Holland, and West Terschelling are shown instance, both surge definitions can be applied Nadal-Caraballo, N.C., Melby, J.A., Gonzalez, Figure 13, 14, 15. in Figures 7, 8, 9. since the basin is relatively shallow and the V.M., and Cox, A.T., 2015. North Atlantic (left to right). tides relatively small. Coast Comprehensive Study—Coastal Storm AEP plot, POT- Skew Surges Results Hazards from Virginia to Maine. Vicksburg, GPD skew surge The model parameter estimates for all Acknowledgements Mississippi: U.S.Army Engineer Research and & Residual: Delfzijl stations are presented in table 3. The Thanks to Dominik Paprotny for sharing the Development Center, ERDC/CHL TR-15-5. station (fig 13); Annual Exceedance Probability plots of the water level data, and to Norberto C. Nadal- Hoek van Holland corresponding GPD best fit for Delfzijl, Hoek Caraballo for allowing the use of the StormSim station (fig 14); West van Holland, and West Terschelling are shown software. I appreciate the time and effort Terschelling station in Figures 10, 11, 12. of all the professors, experts and students (fig 15). from TUDelft and Deltares for replying to my Comparison non tidal residuals and skew enquiries. Thanks to the 2016 PIRE Summer 86 surges (table 4). Research organization team. 87 Appendix A. Appendix B. Appendix C. Appendix D.

Water level records Skew Surges AEP plots Residuals AEP plots AEP plots - Skew Surges vs Residuals

: AEPAppendix plots Skew D: AEP Surges plots vs Skew Residuals Surges vs Residuals

88 89

Figure 1. Joshua Brown Bank Failure Erosion at levee at Loggy Bayou along the Red MATHEMATICAL MODELLING OF MORPHOLOGICAL RIVER River (Bossier City, Louisiana, USA). PROCESSES USED IN THE NETHERLANDS

TO PREDICT BANK FAILURE CAUSED BY EROSION INDUCED BANK FAILURE

Joshua is a MSc student at Jackson State Bohemia, Czechoslovakia. Lastly to give a the increased demand on reliable design University, Mississippi. conclusion as to whether or not this would methods has resulted in development of be a good tool for predictably of which various calculation methods for hydraulic banks and levees would be mostly like to fail loading, morphological changes and Abstract due erosion. All research from this report is erosion prediction. With this introduces new Increasing bank protection along major derived from studies and publications from approaches in preparing a set of design rivers in the United State has always been researchers that have performed experiments methods and guidelines for protection of the important in avoiding flooding and inland with mathematical modeling. banks and structures in the river. navigation issues. These measure are extremely important when it comes to Introduction River morphology caused by erosion is a preventing such disasters the Flood of 1993 One of the major issues with the rivers in major problem in river engineering in all parts along the Mississippi River. The Mississippi the United States is how to prevent the river of the world. Due to depth and the planform river is known to cause major damage due from flooding. Protection against flooding of an alluvial rivers responding to changes in erosion and the lack sufficient protection of and inland navigation along the Mississippi nature and human interferences, can cause a banks and dikes. Flood “control” projects, River has always been extremely important in lowering of the bed nearby. Not anticipating and structural alternatives such as dams the United States. From a national economic the lowering of bed in the design can lead to and levees, provide some measure of viewpoint, continuous flooding of the massive bank erosion. In the present study, protection against the ravages of flooding, Mississippi is one of the most destructive erosion of cohesive banks are incorporated but history has shown time and again that category of natural hazards in the United in a two-dimensional depth-averaged models floods simply cannot be controlled. Also States. How serious is the flooding problem for river morphology. Bank erosion can cause some these structural alternatives may even in the United States? The economic losses channel widening and channel migration, and aggravate the problem by reducing the to homes and personal property, to crops, the eroded bank material becomes sediment decreasing effects of floodplain storage. In business facilities and stock, utilities, and that is transported downstream. There are order to have more protective measures transportation are major manifestations of two types of bank erosion mechanisms that the United States re-evaluate other mean flood losses. The death rate due to flooding exist, those are non-cohesive and cohesive of their flood protection along the rivers. alone is about as great as those due to soil conditions. Non-cohesive soil banks, the The increased demand on reliable design lightning, tornadoes, and tropical cyclones erosion is determined by sediment transport methods has resulted in development of combined. Damages as a result of flooding relations analogously to the erosion of the various calculation methods on hydraulic from the river has amounted in several billion rest of the bed. Bank-line changes depend loading, morphological changes and erosion dollars annually, and it is philosophically directly on bed degradation. For cohesive prediction, and on the other side, in preparing impossible to set a monetary value on human banks, the bank toe divides the boundary a set of design methods and guidelines for life. In fact, one of the worst flooding events into a non-cohesive bed region and a protection of the banks and structures in the in history of the United States happened cohesive bank region. The usual sediment river. One alternative approach in predicting in 1993. The flood of 1993 was a hydro equations apply to the non-cohesive bed bank failure of cohesive soils caused by meteorological event without precedent in region only. The erosion of the banks requires erosion is using mathematical models. These modern US history. The costs to the nation a different approach that takes principles models have been used by the Dutch in from the flood were extensive. Thirty-eight from soil mechanics into account as well. The several applications to predict how cohesive deaths were attributed directly to the flood bank erosion model is modelled by using a banks respond to the mechanisms of erosion. and estimates of fiscal damages ranged time-average description of a sequence of The purpose of this paper is to briefly from $12 billion to $16 billion. Agriculture mass failures induced by toe erosion. The the morphological process, mathematical accounted for over half of these damages. time-average description implies that bank models, and to give an application of More than 100,000 homes were damaged. retreat does not depend on bank stability mathematical model to the morphological Flood response and recovery operations characteristics with respect to mass failure, 90 process on the bend of the Ohfe River in cost more than $6 billion. For this reason, but that it is entirely determined by fluvial 91 entrainment of material at the toe. This does periodically by currents, and gets the most The considerations above justify the use of a be inaccurate. More accurate predictions mechanics of the system. Yang (1971) seems is a natural phenomenon that can be seen not mean that all bank properties become human and animal traffic. The overbank area simple bank erosion law in the models, similar can only be obtained by evaluating the to object to this type of explanation when in most river landscapes. However, in the immaterial in the description, because the is inland of both the toe and bank zones, and to relations for the erosion rate of cohesive time-dependent behavior of the underlying he argues that it is difficult to accept that present Dutch river landscape the natural material at the toe includes cohesive bank can be classified as either a floodplain or a soil samples (Ariathuri and Arulanandan, mechanisms of bank erosion and bank random irregularities can account for the phenomenon of steep and high slopes on material. Only if the influence of the latter bluff, depending on its slope. Most river banks 1978): accretion. If the banks are neither eroding rather consistent geometry of meanders. river banks is almost totally absent. cancels out in the averaging over time, the will respond to erosional activity based on nor growing, the width will remain the same. Nevertheless, the generation of regular waves bank erosion mechanism reduces to a pure the characteristics of the bank material. The If erosion or accretion takes place, there by an arbitrary perturbation is quite common In the past, the river banks were more sediment problem like the one for non- most common type of bank is a stratified will be a transition towards an equilibrium. in many systems of nature. varied and to a certain extent covered with cohesive banks. The purpose of this research or interstratified bank, which consists The width arrived at by bank erosion will vegetation. Nowadays, however, the overall is to study possible alternative approaches of cohesionless layers interbedded with in which dB/dt is the migration rate, E is an be different from the width which results Erosion Due to Navigation picture is one of almost bar and beaches, the Dutch have used to when predicting cohesive layers. If the cohesive soil is at the erodibility coefficient, T is the shear stress from bank accretion. Some researchers For many rivers the lower river bed is except in the transition zone to the estuary, where bank failure may occur due to erosion. toe of the bank, it will control the retreat rate exerted by the near-bank longitudinal flow try nevertheless to obtain a simple single- restricted by dikes and revetment. The bed where there is still marsh land vegetation. of the overlying layer. If the cohesionless soil component and T is a critical shear stress valued width predictor by adding an extra in the dike field between two dikes may be The young soils of the river banks are to Bank Erosion and the Riverine Process is at the toe of the bank, these layers are not below which no erosion occurs. Arulanandan closure relationship, for instance an extremal considered as a beach, visible during low some extent calciferous, in particular the Land-use planning in alluvial river valleys protected by the layers of cohesive soil. et al (1980) give relations to determine the hypothesis. An extremal hypothesis appears water periods. The beach and bank in some soils in front of the summer dikes. Their and the choice of locations for bridges and erodibility coefficient and the critical shear to be just an alternative formulation for dike fields, is often eroded. A reason for such composition varies from coarse sand and hydraulic structures require predictions Mechanics of River Bank Erosion stress of a cohesive soil. Osman and Thorne a simplified version of a fundamental law bank erosion may be navigation, especially gravel in the deeper subsoil, to alternating of future river planform changes and, River-bank erosion is an occurrence in which (1988) consider the approach of Arulanandan already used. As a consequence, the only new when large, fast ships like push-tows use the layers of sand and clay and also thick clay consequently, knowledge of river-bank numerous factors play a role: flow (discharge et al to be one of the most promising of information it brings in is equivalent to the river. Therefore, it is necessary to understand packets. erosion and riverine processes. In particular, flow, groundwater flow, wind waves, ship the currently available methods, because conditions under which the simplification of the erosion process when considering the problem with stabilizing a river planform waves), bed topography, sediment transport, calculation of erodibility and critical shear the fundamental law is valid. River widening the introduction of barge push-towing. Higher areas are dryer and more ripened by constructing protective structures at (e.g. removal of slump debris after mass stress is based on the electrochemical causes aggradation which is caused higher With this knowledge predictions of the and homogenized by the activity of soil certain carefully selected locations only failure and bank properties (bank material properties of the soil, pore water and flow velocities. River aggradation usually extent of erosion can be made and designs fauna and show less hydromorphic features allows for solutions from an economic weight and texture, shear strength including eroding fluid. The bank erosion law is also results from the associated steepening or due prepared for “environment-friendly” river- because of lower groundwater levels. Former and environmental point of view, such as cohesive properties, electrochemical incorporated in a mathematical model for to a freeing from the confinement between bank protection instead of traditional bank river beds or cut-off meanders, have slowly natural banks that provide biotic and abiotic properties, bank height and cross- sectional river morphology. A linear analysis of this banks when the bed becomes higher than protections consisting of layers of stones or turned into marches with organic soils. diversity, which are very important for riverine shape, groundwater level and permeability, model with the approach of DeVriend and the banks (Ikeda, 1989). Degrading rivers may blocks laid on geotextiles. Hydrological factors playa very important ecologically. For this reason, some canalized stratigraphy, tension cracks, vegetation and Struiksma (1983) indicates that the input of assume a narrower width, but not necessarily, role in the distribution of organisms in the streams in Germany have been changed back constructions). bank erosion products decreases transverse because bed degradation can also involve Abiotic Diversity river bank system. Compared with dry into more natural ones by partial removal of bed slopes, but hardly influences the wave significant bank erosion and hence result in In the present situation the low-water channel ecosystems the variations in time and place bank protection works (Keller and Brookes, Cohesive banks usually erode by mass failure, lengths and damping lengths of flow and widening. Thorne and Osman (1988) argue has sufficient capacity to contain the river are great. Most dramatic, for example, is the 1983; Kern and Nadolny, 1986). For rivers in which implies that the banks geometry can bed topography in natural rivers. A more that a critical bank height for mass instability water most of the time without inundating periodic inundation of the river bank which the Netherlands, De Bruin et al. (1986) have fluctuates during bank retreat. Following important effect of an increase in bank poses a limit to bed degradation. Any further the pastures on the higher grounds between only a specialized selection of organisms developed similar ideas, parts of which have mass failure slump, debris accumulates at the erodibility seems to be widening of the bed degradation triggers bank failures and the the dikes. High discharges now flood this can survive. In addition, the water quality of been incorporated in the Dutch government’s bank toe. The debris is removed by lateral and associated shallowing. This change of resulting widening balances the degradation. restricted flood plain only once or twice a the Rhine River deteriorated to a minimum. policy for urban and rural planning. Similarly erosion prior to further bank over steepening width-to-depth ratio leads to longer wave Though this mechanism might sometimes year. Summer dikes have been constructed Recently, a slight recovery has taken place. in the United States, understanding of the or bed degradation generating further mass lengths and less damping. Ultimately, when be effective, it is dangerous to rely on it in in most areas to prevent summer inundation. The effects of pollution are severe because mechanisms of bank erosion along rivers failures. These periodical bank geometry the banks are extremely eroded, the river general. The river can meander and erode the These dikes also prevent polluted water many polluting agents, such as all is that in is imperative for assessing the need for changes cause apparent variations in bank may become braided. banks alternately, thus creating a wide valley entering the summer polder. The low-water the flood plain natural forests of willow and protective works and for the design of these erodibility, consequently complicating erosion floor in which the bed of the actual channel channel is bordered by beaches, dikes and poplar were replaced by pastures, crests of works. This understanding should comprise laws. can be lowered further. other artificial bank protection structures high natural levees were flattened and banks both the riverine morphological processes Model Considerations composed of bitumen, concrete, riprap, were smoothed. that determine the erosive forces, and the soil However, when assuming that the debris is Meandering Rivers blocks and geotextiles. At high discharges mechanical properties of the river banks that removed immediately from the toe, though Width Adjustments Meanders are probably the most intriguing the border is formed by the natural levees Biotic diversity characterize their ability to withstand erosion. still taking complex bank failure mechanisms Another important factor that plays in manifestation of the erosion of river banks. or winter dikes. Geomorphological features Low-water channel borders are almost into account, the time average migration rate predictions of where failure may occur is Yet for a long time the cause of river such as old meanders, steep slopes, old completely without vegetation, because of River banks can be divided into three areas: can be well characterized by a critical shear the width of the river. The width of the river meandering was poorly understood, as was and young natural levees, shallow and deep the turbulent water motion generated by Toe, bank, and overbank area. The toe area stress and an erodibility coefficient of the is important because the width-to-depth reflected by the persistent coexistence of water pits and man-made clay pits, dikes navigation and the sand movement. The is the area which is most susceptible to bank material at the toe (Osman and Thorne, ratio is a key parameter in river morphology. several different theories. Research in the last and other structures create a very complex, higher grounds are less exposed to eroding erosion. Because it is located in between the 1988). Hickin and Nanson (1984), concluded As several values for the equilibrium width two decades, however, has provided decisive continuously changing landscape. forces and carry a permanent vegetation ordinary water level and the low water level, it that bank migration is primarily determined are compatible with a given discharge and evidence that the transition from a straight cover. The impact of the water regime on is strongly affected by currents and erosional by fluvial entrainment of basal sediments, sediment transport (Blench, 1969; Stevens, into a sinuous channel can be explained In places where old natural levees of flood nature is very decisive and governs the events. The bank area is above the ordinary after which cohesive upper sediments erode 1989), single-valued width predictors like from dynamic instability and that a proper plains are exposed to the eroding forces of presence or absence of organisms in the 92 high water level, but can still be effected by the collapse of cantilevered overhangs. the ones in regime theories are bound to description of this instability involves the full the current, steep slopes are created. This flood plain and on the river banks. 93 In early spring when most organisms The mathematical model consists of depth- that derivatives of the flow field with respect with field observations of meandering rivers gradients of sediment transport capacity. For the parameter ranges where all hibernate, the effect of flooding is minimal, averaged equations that are formulated in a to time are assumed to have no influence on by Hickin and Nanson (1984), who find the The corresponding bank retreat follows from contributions are non-zero, the relations for but in summer, flooding can be disastrous horizontal channel-fitted coordinate system sediment motion and bed level changes. The relationship between grain sizes at the outer Figure 4.2. bank erosion are combined to for many plants that are flowering or setting which can be curvilinear and non-orthogonal. assumption holds well for small to moderate bend toe and bank migration resistance to be seeds and some animal’s species can suffer The non- orthogonal curvilinear coordinate Froude numbers (Fr < 0.6 to 0.8). very similar to the Shields diagram. under oxygen depletion. lines in the physical space correspond with orthogonal straight lines in the transformed Bank Erosion Model Erosion at the toe is divided into lateral fluvial There is a relation between the organism and or computational space, Figure 4.1. Places Bank erosion can result from a variety of entrainment of cohesive bank material and This superposition is not justified formally.

the mean duration of annual flooding. At the the physical space can be specified by either mechanisms in which many factors play a near- bank degradation of the non-cohesive The terms with τw and Zb stem from a time- water line, species can be found which are rectangular Cartesian coordinates, (x,y), or role. It can be due to discharge-induced flow bed The retreat due to lateral entrainment is in which ψ is the bank slope angle. This average description in which the term with H resistant to high flow velocities (reed, willow). curvilinear coordinates, (Ɛ/η). The Ɛ direction and sediment transport, but also to processes determined with a simple but generally used contribution to bank retreat vanishes for is supposed to vanish. The equation must be Some species are tolerant to inundation is taken to follow the streamwise direction beyond the basic system of river morphology. relation for the erosion of cohesive soils (e.g. vertical banks (ψ = 90°). looked upon as merely a general expression because they possess aerial canals in their of the river, i.e. more or less parallel to the If the erosion is determined by extraneous Ariathurai and Arulanandan, 1978) for which it is still to be decided which terms stems (reeds, bulrushes). Others have short stream- lines and boundary-conforming at causes only, the rate of bank retreat, | δn/δt |, In Eqs. (4.2) and (4.4), bank retreat must be omitted in a specific application. life cycles to avoid the flooding season. the banks. The η direction is the transverse is simply imposed by immediately follows toe erosion. The The coordinate system is taken to be Organisms most sensitive to flooding are direction, which is not necissarily normal equations are considered to be the outcome orthogonal in regions close to the banks, so found on the crest of the natural levees and to the stream wise direction because the of an integration over an erosion cycle in that Eqs. (4.3) can turn into on dikes. Biotic diversity is also related to soil curvilinear coordinate systam can ne non- which bank geometry and the rate of bank diversity. Clay soils do not dry out quickly orthogonal. retreat fluctuate. Toe erosion decreases bank

since they contain very fine particles and in which nB is the transverse coordinate of in which E is an erodibility coefficient, τw is stability by increasing the slope and the

retain ground water better than sandy soils. As the equations are to be solved in the the bank, t denotes time and F represents the the flow shear stress on the bank and τwc is height of the bank at the beginning of the Permanently water-saturated soils are less transformed space, they must be transformed independent cause of erosion. The absolute a critical shear stress below which no bank cycle, after which the upper parts erode more

aerated or unaerated and so only marsh land as well. The equations become more value ensures that the rate of retreat is erosion occurs. Though the near- bank flow dramatically by mass failure. Debris from where uw is the near-bank flow velocity.

species can grow. complicated then, though they remain of the positive for an eroding bank, regardless of field is essentially three-dimensional, it can mass failure may accumulate at the toe, thus The critical bank shear stress, τwe is defined same type as the original ones (Thompson et whether the bank is on the right or on the be represented well by the longitudinal shear protecting or even buttressing the bank. It analogously in terms of a critical near-bank

al., 1985). left side of the river. The distinction between stress in case of mildly curved flow, because must be removed by the flow before further flow velocity, uwc. Furthermore using Eq. (4.6) Mathematical Model discharge-induced and extraneous causes is secondary flow components are driven toe erosion can take place. During some time and assuming vertical banks, a constant Coordinate Systems Flow Model not sharp. The erosive action of ship waves, by the streamwise flow velocity, and are interval within the erosion cycle, higher and freeboard and no extraneous causes of bank Mathematical models are based on the The mathematical model presented here for instance, also depends on water depth, relatively small with respect to the latter. So steeper banks are more likely to collapse erosion, Eq. (4.7) becomes

conservation of mass and momentum is a depth-averaged model. Its derivation and groundwater seepage can be the result τw can be taken to be the longitudinal shear than lower and less steep ones. The rate of of small volumes of water and sediment, from the full three-dimensional equations of inundation at high discharges. These stress on the banks. It can roughly be related bank retreat can hence be expected to be

whereas the predictions of river banks by means of integration over depth is based indirect effects are disregarded here, however. to the longitudinal bed shear stress, τb, by correlated with bank height and slope when migration span long periods of time. There on a similarity hypothesis, stating that the looking at time scales that are smaller than

is a considerable gap between the scales of vertical profiles of the main flow and the Most alluvial rivers have cohesive banks. the period of the erosion cycle. A relation in which hwc is a critical near-bank water the phenomena and the processes actually secondary flow are self- similar (cf. De Vriend, The cohesion is due to the presence of silt with bank height is assumed as depth, related to the critical bank height by

modeled. Therefore, it is important to reflect 1981). This similarity hypothesis is assumed and clay fractions, or apparent cohesion in which αL = 0.75 for width-to-depth ratios Eq. (4.6). Linearization around the critical

upon the strengths and limitations of this to hold for shallow, mildly curved channels, due to capillary suction or the binding above 5 (Lane, 1955). values, uwc and hwc• yields. approach, and to see whether other methods where most of the flow is not influenced effect of vegetation roots and rhizomes could be more appropriate. by the banks. In large natural rivers, these (Thorne, 1990). Cohesive banks also erode Near-bank bed degradation results from conditions are usually satisfied.The flow is by mass failure during discrete events when assumed to be quasi-steady, which means a critical stability condition is exceeded. Figure 4.2. Erosion of a cohesive river bank by

Osman and Thorne (1988) model the retreat lateral fluvial entrainment, Δnb, and near-bank where G is an erodibility coefficient, H is the With bank properties

Figure 4.1. of cohesive banks as a sequence of mass bed degradation, Δzb, both inducing mass total bank height and He is a critical bank failures induced by erosion at the toe of the failure. height below which no bank erosion occurs. bank. The time- averaged behavior can be The correlation with ip could be postulated modelled as an immediate response to toe in a similar way, but is disregarded here. The erosion. It implies that time-average bank total bank height is given by migration rates are not influenced by bank stability characteristics with respect to mass failure, but that they are entirely determined When the reach-averaged flow velocity and

by fluvial entrainment of material at the toe. in which hw is the near-bank water depth and water depth are assumed to be exactly at the

Osman and Thorne (1988) draw a similar Hfb is the freeboard of the bank. critical values, the latter, i.e. Uwc and hwc, can conclusion for the migration process they be replaced by them. This proofs convenient 94 term ‘parallel bank retreat’. It also consistent in linear analyses, but then Eq. (4.10) ceases 95 to be a pure equation for the underlying the first part of Eq. (4.8), which implies, by The banks are assumed to consist of a numerical models for river morphology, Details of the derivation are given by An analogous definition holds for δ. (s,n). mechanism of bank erosion. The parameters, sediment continuity, that the rate of retreat fraction ω of cohesive material, which Struiksma and Crosato (1989) arrive at Mosselman (1991). The result is The corresponding difference equation used

uwc, hwc, Eu and Eh, no longer represent depends on gradients of sediment transport, becomes washload after being eroded, and in the numerical model implies that bank bank properties only, but they also contain and hence on flow velocity gradients because a fraction (1-ω) of granular material, with the erosion products are distributed evenly over information from the full cross-section. sediment transport is a function of flow same properties as the material of the bed. the area of computational cells next to the Nevertheless, when doing so, the first part of velocity. This is essentially different from Therefore, the input of bank erosion products, in which θ denotes the Shields parameter. banks. In the linear analysis, bank erosion

Eq. (4.14) becomes equal to the equation of the dependence on the non-differentiated sb, to be accounted for in the continuity in which Ss√(1-ε2) and Sn√(1-ε2) are sediment products are taken to be distributed evenly bank erosion postulated by Ikeda et al. (1981). flow velocity in Eq. (4.13) or the bank equation for sediment is Equation (4.15) has been expressed in local transport rates per unit width in directions over the full cross-section, involving

The additional term with hw is proposed by erosion equation of lkeda et al. (1981). When orthogonal coordinates. The orthogonal normal to n and s respectively. In the first Crosato (1989) and Odgaard (1989). the sediment transport also depends on velocity components, û and v, are obtained term, v (l -e2) represents a factor for the other variables, however, elaboration of the from velocity components in s and n area of a parallelogram-shaped base of an To this point, cohesive soil of the banks have sediment transport gradients by applying the direction. The transverse bed slope in the elementary control volume, in accordance

been assumed to extend below the level of chain rule also produces terms in which the local orthogonal coordinate system, δzb / δn’, is with Eq. (2.16). The covariant components, Ss,

the deepest pools. However, only the upper flow velocity appears in non-differentiated Sediment Model related to bed slopes in s,n coordinates by and Sn, are given by 1 layers are cohesive due to vertical grain form only. Linearization makes these terms The sediment model consist of magnitude of An analogous definition holds for δ(s,n). The sorting during the formation of an alluvial similar to the source term in the equation of the sediment transport vector, |s|, is taken to corresponding difference equation used flood plain. This sorting results from previous lkeda et al. (1981), as Hasegawa (1989) shows be a function of the magnitude of the flow in the numerical model implies that bank river migration through the flood plain and in his relation for the rate of bank erosion. velocity vector, |u|, and the streamwise bed erosion products are distributed evenly over from overbank flow (Leopold et al. , 1964). It must be noted that Hasegawa’s relation slope the area of computational cells next to the River-bed grain sorting leads to coarser also contains information on flow field and bank. In the linear analysis, bank erosion sediment grains in the pools and finer grains bed topography of the full cross-section, so In which products are taken to be distributed evenly on the bars. The grains keep their sorted that it is an integrated description instead over the full cross-section, involving distribution when they are buried under new of an equation for an underlying mechanism deposits during river migration. The finest (Mosselman and Crosato, 1991) in which e is a coefficient for the effect of Where vector components are given in s an n grains in the upper layers of the flood plain river bed slopes on sediment transport, and direction. Using cos ψ, this can be elaborated are deposits from overbank flow. River banks fs denotes the sediment transport formula. into With B being denoted as the river width. can still be cohesive on the full height when The relation implies that the sediment Bank erosion also contributes to the the flood plain is in aggradation and overbank transport rate is independent of water depth sediment balance. Treating the input of bank deposition is significant. If only the upper and determined by the local flow field and erosion products as a boundary condition Numerical Model layers are cohesive, bed degradation can bed topography only, which is appropriate for for the transverse sediment transport, The numerical model for river engineering

undermine those layers. When the erosion bed load. For the incorporation of suspended The other quantities in Eq. (4.15) are invariant sn, at the banks is not compatible with is based on the mathematical models. The by lateral fluvial entrainment cannot keep up sediment transport in a depth-averaged in the coordinate transformation. When the notion that the sediment transport is mathematical model presented, which is with the near-bank bed degradation, it does model of river bend morphology, reference is there are no external sources of sediment, determined by the local flow field and bed later introduced in the report is called RIPA, not affect the rate of bank retreat at all. The made to Talmon (1989). the continuity equation for sediment in topography. The bank erosion products are which is derived from the acronym for ‘River retreat is then fully determined by a relation rectangular Cartesian coordinates reads therefore are incorporated as a source term Planform Adjustments’. RIPA is an extension with the form of the first part of Eq. (4.8), but The direction of the sediment transport in the continuity equation for sediment. A of the two-dimensional, depth-averaged

with ψ denoting the angle of the transverse vector is defined as the angle, ψ, between the in which Sx and Sy are sediment transport distribution function, δ(s,n), specifies how model for river morphology developed by

bed slope close to the bank instead of the Figure 4.3. Erosion of a cohesive river bank vector and the s direction. It is determined rates per unit width in x and y direction the supply of eroded bank material, SB (s), Olesen (1987).The similarity of vertical flow bank slope angle. This is the bank erosion by near-bank bed degradation, inducing mass by the depth-averaged flow direction, the respectively. Equation (2.8) transforms this is distributed over the cross-section of the profiles holds for shallow, mildly curved rivers. mechanism Hasegawa (1991) refers to. As failure. deviation of the near- bed flow direction equation into river. Elaboration for orthogonal curvilinear Olesen (1987) concludes from simulations of the non-cohesive bed next to the cohesive from the depth-averaged flow direction due coordinates yields curved-flume experiments, that the model is bank inclines towards the deeper parts of the to secondary flow, and the effect of gravity not applicable when the width-to-depth ratio cross- section, the semantic problem arises on sediment grains on a sloping bed (Van is smaller than about 10, but that a rather of whether it actually is a part of the bed, or Bendegom, 1947; Engelund, 1974). In the form strong center-line curvature with a radius of rather a part of the bank. Because erosion used by Struiksma et al. (1985), ψ is given by about twice the river width does not give and accretion are determined by the same This equation is elaborated further by in which i = 1, denotes the right bank where problems. Assuming small Froude numbers, a

sediment equations as the ones for the rest changing from ;q coordinates to s,n n = nB1 and i = 2 denotes the left bank where rigid-lid approximation is applied at the water

of the bed, it is considered to be a part of coordinates, by changing from vector n = nB2. The distribution function satisfies surface. The bed topography can then be the bed, and because defining the boundary components in the directions of the described by the distribution of water depths. between bed and bank would be arbitrary in which f(θ) is a function weighing the rectangular Cartesian coordinates to otherwise. influence of gravity pull along a transverse components in the directions of the Although cohesive eroding banks are very bed slope. From experimental data presented curvilinear coordinates, and by replacing all A distribution over a narrow zone along the steep, the depth-averaged flow model is not Figure 4.4 shows that the erosion of non- by Zimmermann and Kennedy (1978), and derivatives of x and y with respect to an, by eroding bank is obtained by defining very accurate in regions close to steep banks, 96 cohesive banks can also be described by Figure 4.4. Erosion of a non-cohesive bank. with experience from the calibration of skewness and coordinate line divergences. δ(s,n) as a Dirac delta function. because lateral friction is neglected and the 97 Figure 5. underlying similarity hypothesis for vertical by Parker et al. (1982, 1983), are primarily due The widths of straight rivers cannot be Erosion of a cohesive flow profiles is not valid there. An erroneous to the confinement within a narrow valley. stabilized by protecting certain carefully river bank along growth of the main velocity at concave banks chosen bank sections only, unless these the Ohfe River is prevented by an artifice for the near- Numerical Model Observations from the Ohfe sections are so closely interspaced that other (Eger) in Bohemia, bank decay of the secondary flow intensity River effects, not included in the model, become Czechoslovakia (Olesen, 1987). Errors in the description of the For this application, a mathematical model significant. Although some results of the flow field close to the banks propagate along was implemented into a numerical model, suggested the initiation of meandering, characteristics. The characteristics are known RIPA to simulate the Ohfe River. RIPA’s computing the development of a straight to shift towards the concave bank due to formulation in non-orthogonal curvilinear river into a meandering planform failed secondary flow convection, but they match coordinates allows the use of a boundary- because bank accretion has not been with the streamwise coordinate lines in the fitted computational grid, suited for rivers. included in the model. simplified model used here (cf. Kalkwijk and A main feature here is that all derivatives De Vriend, 1980). This means that flow field of rectangular Cartesian coordinates with The results of applying the model to a reach errors at steep banks do not spread towards respect to curvilinear coordinates are of the river Ohfe in Czechoslovakia was not the central flow field, though some influence replaced by properties of the coordinate very successful. RIPA proved that better is present through the integration over system that are invariant for rotation of the sub models for flow and sediment transport cross-section for the condition of continuity. system. Among these properties are the are needed, that account for non-uniform Another effect of an inaccurate description local skewness and the divergences of the roughness, suspended sediment transport, of the near-bank flow is that it hampers an coordinate lines. The advantage of using sediment mixtures and armoring. Maybe accurate modelling of flow-induced bank these properties instead of coordinate a proper description of the flow close to erosion. derivatives is that their values, and a bank can only be obtained with a three- hence their contribution to the solution, dimensional flow model. Furthermore, adding The concern with numerical model is that it can be judged far more easily from a visual a sub model for bank accretion seems very tends to become unstable above high point inspection of a plot of the grid. They also important. The general behavior of RIPA bars, due to the flow field that is general no facilitate the physical interpretation of suggests, nevertheless, that the shortcomings longer gradually varied when the water depth transformation terms. do not detract from using an integrated above a sloping bed becomes locally too approach based on interactions of underlying small. Inertia are ignored when the distances A bank was incorporated into a two- mechanisms. between the points of the computational grid dimensional depth- averaged model for river are too large. The instability can be removed morphology from the Ohfe River. Several Conclusion by decreasing the grid point spacing. different mechanisms of bank erosion also In order for mathematical models such as exist for this river. The ones considered here RIPA, there must be better sub models for Application of the Numerical Model are time-average descriptions in which the flow and sediment transport to account An application of the numerical model was rate of bank retreat is proportional with the for these underlying issues. The current applied to a reach of the Ohfe River (Eger) excess flow shear stress above a critical value, knowledge and mathematical tools for in Bohemia, Czechoslovakia. This river begin the excess bank height above a critical value, treatment of bank erosion are forthcoming from the Fichte Mountains in Germany and and the rate of near-bank bed degradation but are not still adequate for solving is a tributary to the river Labe (Elbe), Figure due to a local sediment imbalance. The complicated practical treatment of problems. 5.1. Its total length is about 300 km. The banks are assumed to consist of a fraction reach under consideration is about 15 km of cohesive material, which washes away The current knowledge on erosion and from the confluence, at the Ohfe Meanders after being eroded, and a fraction of granular sedimentation processes due to interaction of near Hostenice, shown in Figure 5. The material, with the same properties as the natural currents, waves and water stages and Pisty Woods are a nature reserve where material of the bed and bank deposits has protective structures is still in a rudimentary the meander bends are allowed to migrate been disregarded. stage and it is not yet possible theoretically freely. The shape of the river in Figure 5 is to describe many phenomena and their interesting in view of a discussion on the Also the equations for the morphology of interactions. The natural resistance of various extent to which the skewing of river bend rivers with erodible cohesive banks formed types of vegetation against hydraulic loading planforms can be ascribed to geometric a determinate system when mechanisms for is still not sufficiently evaluated, especially non- linearity or to lateral confinements. The bank erosion and accretion are included. The regarding the soil and the conditions coexistence here of sharp skewed bends on predictions of the development of meanders after planting, and the methods of their the left, where the river impinges on hills, and and the adjustment of widths were based (temporary or permanent) protection. Still round bends on the right supports Ikeda’s on a mathematical model deduced from more research is needed on that especially (1989) opinion that the sharp skewed bends descriptions of underlying mechanisms that related to two-and three-dimensional 98 of the Beaver River in Alberta, Canada, shown operate on a small scale. treatment of problems. 99 Figure 6. In conclusion, although mathematical References process. In: Biogeomorphology, Ed. H.A. Viles, bank erosion. Communications on Hydr. Erosion of a river tools are important for sensitivity studies Ackers, P. and W.R. White (1973), Basil Blackwell, pp.11-42. Griffiths, G.A. (1984), and Geotech. Engrg., No.89-3, Delft Univ. of bank along the and for making a proper choice from Sediment transport: new approach and Extremal hypotheses for river regime: an Technol. Rhine River, The alternative solutions, the complexity of the analysis. J. Hydr. Div., ASCE, Vol.99, No.HY11, illusion of progress. Water Resources Res., Mosselman, E. (1991), Modelling of river Netherlands. (Image river morphology and the mechanics of pp.2041-2060. AGU, Vol.20, No.1, pp.113-118. morphology with non-orthogonal horizontal by Rijn In Beeld) bank erosion for some specific problems, Ahmad, M. (1973), Charter V: Sediment Hagerty, D.J. (1991), Piping I sapping erosion. Communications on Hydr. and Geotech. physical scale modelling is still the best control methods: C. Control of sediment in I: Basic considerations. J. Hydr. Engrg., ASCE, Engrg., No.91-1, Delft Univ. of Technol. investigation tool. Computer models are canals (discussion). J. Hydr. Div., ASCE, Vol.99, Vol.117, No.8, pp.991-1008. Universal bank Mosselman, E. and A. Crosato (1991), under development to describe the water No.HY7, pp.1176-1178. erosion coefficient for meandering rivers Curvilinear coordinates. Universal bank motion and to check for the stability of Ariathurai, R. and K. Arulanandan (1978), (closure of discussion). erosion coefficient for meandering rivers alluvial stream and river banks. In my Erosion rates of cohesive soils. J. Hydr. Div., Heinzelmann, Ch. and S. Wallisch (1991), (discussion). J. Hydr. Engrg., ASCE, Vol.117, assessment of the application in this report ASCE, Vol.104, No.HY2, pp.279-283. Benthic settlement and bed erosion, a review. No.7, pp.942-943. the Mathematical Model would not be a Arulanandan, K., E. Gillogley and R. Tully J. Hydr. Res., JAHR, Vol.29, No.3, pp.355-371. Murphey Rohrer, W.L. (1983), Effects of flow good predictor of bank instability due to (1980), Development of a quantitative Hickin, E.J. and Howard, A.D. (1983), and bank material on meander migration in the inconsistencies stated above and more method to predict critical shear stress Simulation model of meandering. In: River alluvial rivers. In: River Meandering , Proc. research is done to accommodate associated and rate of erosion of natural undisturbed Meandering , Proc. Conf. Rivers 1983, New Conf. Rivers 1983, New Orleans, Ed. C.M. with the errors involved. cohesive soils. Rep. GL-80-5, U.S. Army Orleans, Ed. C.M. Elliott, ASCE, 1984, pp.952- Elliott, ASCE, 1984, pp.770-782. Engineers, Waterways Exp. Stn., Vicksburg. 963. Murshed, Kh.Gh. (1991), Effect of bank erosion Bakker, B., H. Vermaas and A.M. Choudri Jansen, P.Ph., L. van Bendegom, J. van products on meander migration. M.Sc. Thesis Acknowledgements (1989), Regime theories updated or outdated. den Berg, M. de Vries and A. Zanen (1979), H.H. 82, IHE, Delft. Figure 7. I would first like to thank professors Erik Delft Hydraulics Puhl. No.416. Principles of river engineering. Pitman, Nagel, E. (1961), The structure of science. Erosion of a river Mosselman, Myron van Damme, Henk Bendegom, L. van (1947), Some London. Second Ed. (1979), Hackett, Indianapolis bank along the Waal Jan Verhagen, and Mark Voorendt at The considerations on river morphology and Lamberti, A. (1988), About extremal Olesen, K.W. (1983), Alternate bars in and River at Oosterhout, University of Delft for agreeing to meet river improvement. De Ingenieur, Vol.59, No.4 hypotheses and river regime. Int. Conf. River meandering of alluvial rivers. In: River The Netherlands. with me during their busy schedule during (in Dutch; English transl.: Natl. Res. Council Regime, 1988, Wallingford. Meandering, Proc. Conf. Rivers 1983, New (Image by ARK) our visit in the Netherlands. I very much Canada, Tech. Translation 1054, 1963). Lane, E.W. (1955), Design of stable channels. Orleans, Ed. C.M. Elliott, ASCE, 1984, pp.873- appreciate the wealth of knowledge each Berlamont, J. and M. Schiara (1983), Trans. ASCE, Vol.120, Paper No.2776, pp.1234- 884. shared with me in their respective fields of Local channel stabilization of reach-type 1260 (also Proc. ASCE, Separate No.280, Olesen, K.W. (1987), Bed topography in study and the candor shown while in their rivers. In: River Meandering , Proc. Conf. 1953). shallow river bends. Communications on presence. Rivers 1983, New Orleans, Ed. C.M. Elliott, Laplace, P.-S. de (1814), Essai philosophique Hydr. and Geotech. Engrg., No.87-1, Delft Univ. ASCE, 1984, pp.985-995. sur les probabilites. Text of fifth Ed., 1825, of Technol. I would also like to thank the personnel at Blench, T. (1969), Mobile-bed fluviology. Univ. in French, Ed. Chr. Bourgois, Collection Osman, A.M. and C.R. Thorne (1988), PIRE (Dr. Sam Brody, Dr. Bee Kothuis, Dr. of Alberta Press, Edmonton. Episteme, 1986. Riverbank stability analysis. I: Theory Yoonjeong Lee, Dr. Antonia Sebastian, and Blondeaux, P. and G. Seminara (1985), Larsson, R. (1986), Coriolis generated Struiksma, N. and A. Crosato (1989), Ms. Sherry Parker) and the National Science A unified bar-bend theory of river meanders. secondary currents in channels. J. Hydr. Analysis of a 2-D bed topography model foundation for the opportunity to visit the J. Fluid Mech., vol.157, pp.449-470. Engrg., ASCE, Vol.112, No.8, pp.750-756 for rivers. In: River meandering , AGU, Water experts at the UT Delft. Without their input Bohemen, H.D. van, D.A.G. Buizer and A. Leopold, L.B., M.G. Wolman and J.P. Miller Resources Monograph 12, Eds. S. Ikeda and G. and guidance, the trip to the Netherlands Littel (Eds., 1991), Nature engineering and civil (1964), Pluvial processes in geomorphology. Parker, pp.153-180. Figure 8 would not have been a success. engineering works. Rijkswaterstaat, Road and Freeman, San Francisco. Lorenz, E. (1963), Talmon, A.M. (1989), A theoretical model for Caving of a river Hydr. Engrg. Div., Puhl. Pudoc, Wageningen. Deterministic nonperiodic flow. suspended sediment transport in river bends. bank due to I would also like to acknowledge my advisor, Booij, R. (1988), Coriolis generated secondary J. Atmospheric Sciences, Vol.20, pp.130-141. Communications on Hydr. and Geotech. extreme high water Dr. Robert Whalin, Director at the Coastal currents in channels (discussion). J. Hydr. Luzbetak, D.J., S.C. Jain and A.J. Odgaard Engrg., No.89-5, Delft Univ. of Technol. levels along the Hazard and Resilience Center at Jackson Engrg., ASCE, Vol.114., No.3, pp.348-350. (1988), Piping as a mechanism of bank Thompson, J.P., Z.U.A. Warsi and C.W. Mastin IJssel River, The State University. Thanks for providing Brookes, A. (1988), Channelized rivers: erosion along rivers in Iowa. Rep. No.324, (1985), Numerical grid generation.North- Netherlands (Image leadership and guidance before, during and perspectives for environmental management. Iowa Inst. Hydr. Res. Holland, New York.(1990), by Rijkswaterstaat, after the trip to the Netherlands Wiley-Interscience.Fourth Int. Symp. River Meadows, D.L. (1972), The limits to growth - a Vriend, H.J. de (1976), A mathematical model Ronald van Etten) Sedimentation, Beijing, 1989. report for the Club of Rome project on the of steady flow in curved shallow channels. Gill, M.A. (1968), Rationalization of Lacey’s predicament of mankind. Universe Books, Communications on Hydraulics, No.76-1, Delft regime equations. J. Hydr. Div., ASCE, Vol.94, New York. Univ. of Technol. No.HY4, pp.983-995. Meyer-Peter, E. and R. Muller (1948), Formulas Vries, M. de (1965), Considerations about non- Gleick, J. (1987), Chaos: making a new for bed-load transport. Proc. 2nd Congress steady bed-load transport in open channels. science. Viking, New York. JAHR, Stockholm, Paper No.2, pp.39-64. Proc. 11th Congress JAHR, Leningrad (also Gregory, K.J. and A.M. Gurnell (1988), Mosselman, E. (1989), Theoretical Delft Hydr. Lab. Publ. No.36). 100 Vegetation and river channel form and investigation on discharge-induced river- 101 Figure 1. (right) Benjamin Bass Difference in structure and location where DEVELOPMENT OF A HAZARD INDEX FOR WINTER STORMS hurricanes versus winter storms develop (modified from NHC, 2015)

Benjamin is a PhD student at Rice UnIversity, Both hurricanes and winter storms well as rainfall that can result in increases Houston. are cyclonic, or have winds that rotate in overall inundation levels. All of these counterclockwise in the northern hemisphere; hazards can be considered when describing a however, the energy source for hurricanes hurricane or winter storms potential impacts; Overview of Hurricanes and Winter Storms are driven by latent heat release due to deep however, storm surge is typically the primary The U.S. Gulf and Atlantic coast is exposed convection, while winter storms are driven by hazard associated with these storms. to infrequent, but severe hurricane events instabilities in pressure gradients due to the that occur from 10-35 degrees north interaction between warm and cold fronts. Objective of Study latitude. These storms have a relatively clear As compared to hurricanes, these storms Surge indices are widely used for public Figure 2. (below) meteorological structure, with a single low- are less intense, larger, and less defined in advisories during impending hurricane or a) Return period pressure core that fills with warm air from their structure due to their potential to result winter storm strikes. While such indices storm surge levels surrounding areas with higher pressures. in multiple low- and high-pressure areas should never replace graphical forecasting along the Dutch Given favorable environmental conditions (Figure 1). In the U.S. these storms are called products, they can provide a useful indication coast (at Egmond) such as warm and moist air, minimum sea Extratropical when a hurricane reaches of a storms potential to generate storm compared to surface temperatures of 80 deg. F., and northerly latitudes, interacts with northerly surge, particularly for those without access Galveston Bay low wind shear, a hurricane can develop cold air masses, and transitions into a storm to graphical forecasting products. In addition, (data from Ebersole (classified as winds > 74 mph). The pressure with a cold core. these surge indices are typically used to et al. (2015) and gradient in a hurricanes windfield can be discuss or describe a given storms strength Baart et al. (2011), described by an exponential increase in Winter storms can result in significant or capacity to generate storm surge relative respectively). pressure from a low pressure at the core storm surge that can well exceed 3 meters to other storms. The objective of this study is b) Return period of a hurricane (i.e. 900 to 980 millibars) to (or roughly 10 ft.) when combined with to evaluate the effectiveness of the Beaufort wind speeds along ambient pressures (typically around 1012-1015 high tides such as that which occurred scale in depicting coastal storm surge and, if the Dutch coast mb) at the edge of a hurricanes windfield during the infamous North Sea flood of necessary, develop an index that can predict (Rotterdam) and (Figure 1). 1953. However, as compared to hurricanes, storm surge from winter storms, which is the Galveston Bay (Van stillwater or skewed surge levels (storm primary flood hazard the Dutch coast faces. Den Brink et al. North of the tropics, or more specifically surge without the influence of tides) from This study was motivated by the fact that (2005) and Emanuel mid-latitude regions from 35-60 degrees winter storms are typically lower owing to Europe uses a similar scale to the Saffir- (2014), respectively). north (i.e. north of New York, which includes their weaker wind intensities in addition to Simpson Hurricane Scale (SSHS) to refer the Netherlands), do not have warm enough the less defined structure of the storms. For to the strength of a winter storm. The sea surface temperatures for hurricanes to example, the 100-yr stillwater storm surge Beaufort scale, similar to the SSHS, defines develop or sustain themselves. However, level due to hurricanes in the U.S. Gulf coast a storms “category” or “force” according to during the winter southerly warm air and are actually greater than 1000-yr stillwater its maximum wind intensity (Tables 1 and northerly cold air that flow toward each other surge levels produced from winter storms 2). This led to concern given that the SSHS can lead to cyclones in this mid-latitude partially due to the differences in wind has recently been shown to provide very region. These cyclones, which have cold speeds associated with these storms (Figure poor predictive skill in describing hurricanes cores, as compared to hurricanes which have 2). These differences in return period surge ability to develop storm surge (Powell and warm cores, are called nor’easters in the levels would make it difficult for the U.S. Reinhold 2007; Bass et al. 2016). Rather U.S. and European winter storms in Europe to adopt the 10,000 year flood protection than defining a hurricane by a single wind (referenced as winter storms from now guidelines typically achieved throughout the value in the entire storms windfield, Bass onward). Aside from riverine flooding, these Netherlands. et al. (2016) demonstrated that alternative type of winter storms are the main natural surge indices that incorporate additional hazard threat to the Netherlands, and have In addition to storm surge, hurricanes and descriptors of a storms intensity and size led to the construction of a series of barriers winter storms can result in significant wave can significantly improve the prediction of 102 along the Dutch coast called the Delta Works. action that may lead to coastal erosion as a storms potential to generate storm surge. 103 Table 1. As such, this research was motivated by the curve, demonstrating little relationship Saffir-Simpson idea that the Beaufort scale, which is widely between max wind speed and skewed surge Hurricane Scale used by the European and Dutch population (not shown). It is worth noting that the (SSHS) (data from to refer to the strength of a storm, could be a dataset of winter storms (as shown in Figure Simpson 1974; poor indicator of a winter storms potential to 4) includes two types of outliers. These National Weather generate storm surge given its dependence include 2 storms with high intensity wind Service 2007). on a single maximum wind speed value. speeds, but low surge levels and the 1953 storm, which had a very high skewed surge The SSHS is based on a hurricanes level compared to any other storm for the maximum 1-minute sustained wind speeds 1898-2010 time period evaluated. and thresholds for different hurricane categories were developed based on Subsequently, different characteristics of empirical engineering judgement (Saffir- the storms, including storm speed, angle, Simpson 1974). Surge levels were associated and size, were evaluated against skewed Table 2. with each category of the SSHS by the surge levels to determine if a correlation or Beaufort scale, National Weather Service shortly after relationship. existed between skewed surge including force, the development of the SSHS (reference Figure 3. and these different storm characteristics corresponding knots, Table 1). The Beaufort scale was developed Location of the Hook of Holland gauge where (Figure 5). Size in this study was defined as and qualitative in 1806 to relate maximum 10-minute peak skewed surge levels were obtained for the distance between the lowest low-pressure descriptions for sustained wind speeds to the state of open analysis in this study. core of the winter storm and ambient each force. Beaufort seas. This scale was also developed based pressures. As demonstrated in Figure 5, forces 10-12, which on empirical observations; albeit by 100+ angle and forward speed seem to have some represent winter years of reports from open sea ships. While influence on the skewed surge response of storm wind speeds originally developed for waves in open-seas, storms was compared to observed skewed the storms. The 1953 storm surge level is still are highlighted. the Beaufort scale was later expanded to surge levels. The coefficient of determination clearly an outlier for angle and forward speed; include descriptors of wind intensity for (R2) was used to evaluate the ability of however, other outliers do not appear such as inland areas. The SSHS provides specific the Beaufort scale to estimate a storms the 2 storms that have extremely high wind ranges of surge levels associated with a corresponding surge levels. speeds in Figure 4. On the other hand, storm hurricanes category; however, the Beaufort size has a poor relation to skewed surge scale is primarily defined by qualitative Meteorological characteristics, including levels, and includes the same outliers that had descriptors of a storms influence on waves in the storms track, pressure, size, and angle high wind speeds in Figure 4. the open ocean and has not necessarily been were then additionally collected (data from evaluated in terms of its correlation to storm Matthijs de Jong 2012) to develop modified Of all the storm characteristics evaluated, surge along coastal areas. In addition, while or expanded versions of the Beaufort scale. angle of approach has the strongest the SSHS table is specific to hurricanes (> 74 These modified indices were compared correlation to skewed surge levels (Figure mph); the Beaufort scale begins at zero knots against skewed surge levels to evaluate if an 5a). The maximum skewed surge levels and is used for daily purposes for Beaufort’s 1 improved index, as compared to the Beaufort typically occur with storms that strike through 9, and only applies for winter storms scale, could be developed for representing a shore-normal to the Dutch coast (defined for Beaufort’s 10 through 12 when wind winter storms ability to generate surge along as 0°, with negative values representing speeds are greater than 48 knots (55 mph) the Dutch coast. counterclockwise from shore-normal). This as highlighted in Table 2. physically makes sense since storms striking Results shore- normal are more likely to direct their Methodology Figure 4 demonstrates the performance of winds towards the coastline, and agrees with Observed peak skewed surge levels (surge – the Beaufort scales (maximum 10-minute numerical analysis performed for hurricane tidal influence) and maximum 10- sustained wind speed) ability to represent events (Irish et al. 2008). A relationship minute sustained wind speeds were obtained or predict skewed surge levels from the 20 between forward speed and skewed surge at the Hook of Holland gauge (shown in winter storms occurring from 1898 to 2010. is not readily apparent (Fig. 5b). The best Figure 3) for 20 winter storms occurring As demonstrated in Figure 4, the Beaufort polynomial fit is included in the forward between 1898 to 2010 (data from Matthijs scale has an extremely weak correlation to speed plot; however the trend observed in S. de Jong 2012). These skewed surge levels skewed surge levels for a linear regression the polynomial fit does not have a physical take into account relative sea level rise. This model (R2=0.0010), demonstrating that it interpretation. As a result, this characteristic gauge was used owing to its long recording provides nearly no indication of a winter was removed and not considered for an history. The correlation of the Beaufort storms ability to develop storm surge. The R2 expanded Beaufort scale (index) for surge 104 scale or the maximum wind speed of the 20 increased to 0.057 when fit by a polynomial prediction purposes. Finally, storm size was 105 Figure 4. (right) evaluated against skewed surge as shown intensity and angle. While the R2 of this final and thus erosion caused by each of these Max wind speed in Figure 5c. The observed data seems to index is lower than that observed for angles storms in addition to their associated compared to the suggest that smaller storm sizes may result relationship to skewed surge, it allows for rainfall are important hazards of winter peak skewed surge in greater skewed surge levels. Smaller the representation of a more intense storm’s storms that should be incorporated into levels for the 20 sizes may correspond to storms with better ability to generate higher surge levels. an expanded index predictive of a storms historically observed defined structures and thus possibly high potential for overall impacts as compared winter storms. intensity winds in a more concentrated area Limitations and Future Work to solely skewed surge. Since wave data Beaufort forces as compared to larger storms. However, This research was significantly limited by is very limited along the Dutch coast this are included and given the weak correlation in the data and the amount of data available and access analysis could be supported with numerical separated by vertical the1953 storm not agreeing with this theory, to numerical experiments that could have experiments of historical and synthetic lines. storm size was not considered in a modified supported analysis. In terms of historically storms like that suggested previously for Beaufort scale (index). observed data, only 20 storms were available skewed surge analysis. Wave models such for evaluating the correlation of different as Simulating WAves Nearshore (SWAN) Figure 5. Based on the evaluation of different storm winter storm characteristics to skewed surge can easily be simulated in tandem with a) Angle of properties and their correlation to peak levels. Very little correlation was seen for hydrodynamic models like ADCIRC for this approach, skewed surge levels, a modified Beaufort the majority of the storm characteristics purpose. Erosional impacts can then be b) forward speed, scale was developed. Wind intensity was evaluated, which is partly due to the less evaluated in models such as Delft-3D or and included in this scale despite its poor well defined structure of winter storms, but XBeach. The rainfall resulting from each of c) storm size correlation to the skewed surge levels also due to the limited number of storms for the winter storms may be available; however, compared against owing to its physically known influence of which data is available. This was particularly I was unable to obtain such information. If skewed surge levels. shear stress along the ocean surface or an issue owing to the limited observational such data is unavailable, physical models direct influence on storm surge. Angle was responses recorded for the winter storms (i.e. representing a winter storms potential to additionally included owing to its correlation analysis was limited to observed peak skewed generate rainfall would be required. Such and explainable trend to skewed surge surge levels at the Hook of Holland gauge). rainfall models exist for hurricanes (i.e levels. Similar to Kantha (2008), these two Ideally, the peak skewed surge level along the Langousis and Veneziano 2009), and likely parameters were normalized by reference entire Dutch coast would have been known could be developed for winter storms, if not values to develop a winter storm surge index. rather than this single location. already in existence, based on the pressure gradients of a winter storm. The maximum 10-minute sustained wind Using numerical simulations of historical In summary, future work should couple speed data was simply normalized by the winter storms in a hydrodynamic model such the analysis performed in this study with maximum wind speed of 88 knots that as the tightly coupled ADvanced Circulation numerical experiments of not only storm was observed for the 20 winter storms. (ADCIRC) or WAQUA model’s would have surge, but also wave action / erosion, and This allowed for a linear representation of allowed for a more regional analysis of the rainfall associated with these storms in order wind speeds physically known influence storm surge response, including the peak to develop an index capable of representing a on surge levels as shown in Figure 6a. The surge level along the entire Netherlands storms overall hazard. empirical equation from the polynomial coast, as well as other regional surge metrics curve fit between angle and skewed surge that storms may have a correlation to such as Conclusions was linearized. This was performed by land area inundated for each corresponding This study demonstrated that Beaufort normalizing predicted skewed surge values storm. Having access to the wind- and forces representative of winter storms (> 48 based on the curve fit by a skewed surge pressure-field representation of these knots; forces 10-12) are poor indicators of a of 50 cm. This reference skewed surge historical storms would additionally allow for storms potential to generate storm surge. As value was chosen in order to increase the more complex characterizations of the storms a result, this scale, which is based on a single weight of the angles influence on skewed beyond those characteristics evaluated in maximum wind speed value, like the Saffir- surge levels as compared to wind intensity. this study, including terms such as the kinetic Simpson categories used in the U.S., has Figure 6b demonstrates the resulting linear energy of the storms, the number of low- limited utility during public advisories, at least representation of angles influence on skewed pressure cores, etc. In addition, this would in terms of a storms potential to generate surge levels. Finally, the respective weights allow for the development and analysis of storms surge. The angle of approach of of wind intensity and angle were simply synthetic winter storms to supplement the winter storms was found to have the summed in order to develop a surge index for limited list of observed storms. strongest correlation to skewed surge levels depicting a given winter storm’s potential to observed for 20 winter storms. Subsequently, generate storm surge. This final winter storm This study only evaluated peak skewed angle of approach and wind intensity were surge index is shown in Figure 7, and provides surge levels given the limited information combined into an index reflecting their a simple parameterization for predicting associated with the historically observed relative influence on historically observed 106 peak surge levels based on a storm’s wind winter storms. However, the wave action skewed surge levels. This index can better 107 Figure 6. represent a winter storm’s ability to generate References Van Den Brink H.W., Konnen G.P., Opsteegh a) Normalized wind peak skewed surge levels than the Beaufort Baart F., Bakker M.A.J., van Dongeren A., J.D., van Oldenborgh G.J., and Burges G. intensity and scale; however, this index should be den Heijer C., van Hetern S., Smit M.W.J., van (2005). Estimating return periods of extreme b) normalized validated, and improved, with hydrodynamic Koningsveld M., and Pool A. (2011). Using 18th events from ECMWF seasonal forecast angle, with the model experiments. In addition, an index century storm-surge data from the Dutch ensembles. International x-axis representing representative of the overall hazard of Coast to improve the confidence in flood- the corresponding a winter storm should be developed by risk estimates. Natural Hazards and Earth weights associated considering wave action or the erosion Sciences. with each storm capacity and rainfall associated with these Bass, B., Irza, J.N., Proft, J., Bedient, P., and characteristic. storms. Such an index could be very useful Dawson, C (2016). Fidelity of the Integrated for public advisories in order to describe the Kinetic Energy Factor as an Indicator of hazard associated with impending or ongoing Storm Surge Impacts. Natural Hazards. DOI: winter storms. In addition, this index could 10.1007/s11069-016-2587-3. be useful for putting the overall hazard of Ebersole B.A., Massey T.C., Melby J.A., Nadal- different winter storms into context. Caraballo N.C., Hendon D.L., Richardson T.W, and Whalin R.W (2015). Interim Report – Ike Dike concept for reducing hurricane storm surge in the Houston-Galveston region. Emanuel, K. (2014). Hurricanes in the Gulf of Mexico: The history and future of the Texas coast. Presentation at the University of Texas at Austin, Environmental Science Institute. Irish J.L., Resio D.T., and Ratcliff J.J. (2008). The influence of storm size on hurricane surge. Journal of Physical Oceanography (38), 2003-2013. Kantha, L. (2008). Comments: Tropical cyclone destructive potential by Integrated Kinetic Energy. American Meteorological Society, BAMS, 219-221. Langousis, A. and Veneziano D. (2009). Theoretical model of rainfall in tropical cyclones for the assessment of long-term risk. Journal of Geophysical Research (114). National Oceanic and Atmospheric Administration (NOAA) National Hurricane Center (NHC) (2015). Tropical Cyclone Climatology. < http://www.nhc.noaa.gov/ Figure 7. climo/> Accessed: 6/9/2016. Final index developed National Weather Service (2007). The Saffir- for representing a Simpson hurricane scale. http://www.nhc. storms potential to noaa.gov/aboutsshws.php. Accessed 25 Mar generate storm surge. 2016. Index includes the Powell MD, Reinhold TA (2007) Tropical influence of a storms Cyclone Destructive Potential by Integrated wind intensity and Kinetic Energy. Bulletin of the American angle. Meteorological Society 88(4): 513-526. Simpson RH (1974). The hurricane disaster- potential scale. Weatherwise (27), 169 and 186. Matthijs S. de Jong (2012). Developing a parametric model for storms to determine the extreme surge level at the Dutch coast. 108 Master’s Thesis, TU Delft. 109 THREE | STUDENT RESEARCH REPORTS 2017

110 111 NSF-PIRE 2017 Case #1 NEW TOWNS COPING WITH FLOOD RISK O#3

LAKE IJSSEL: ALMERE AND IJBURG-AMSTERDAM

Metropolitan areas around the world face a problem of rapid increase Specific research questions (RQ) and tasks will be developed based Image above: in population, leading to development of new towns or suburban on composition and preferences of the whole multidisciplinary team. Case study location. communities to accommodate rising growth in urban centers. The following overarching questions can serve as a guide to further However, these newly developed towns are often vulnerable to flood development, but you can also develop your own RQ: Image to right: hazards because of the pressure to develop in floodplains with little Amsterdam IJburg, consideration for the associated human and environmental impacts. RQ 1: What are planning/management factors of resilient new towns? reclaimed land in the For example, the Clear Creek watershed in the Houston-Galveston RQ 2: What types of building would be resilient to floods? Lake IJssel, in the area is home to several newly incorporated communities that have RQ 3: What kinds of critical infrastructures should be included in new form of islands. recorded repeated flood damages in recent times. Despite having towns? the opportunity to apply best management practices in developing RQ 4: What are the differences between flood-resilient new towns in a resilient and sustainable community, many new towns are far from the Netherlands and flood-prone, newly developed suburban area in achieving such resiliency to natural hazard. the US? RQ 5: How have adaptive capacity, environmental, and institutional While many metropolitan cities and their surrounding new towns are factors contributed to disaster resilience of new towns? dealing with increased losses from flooding, their contemporaries RQ 6: What adaptive strategies are adopted in flood-resilient new in the Netherlands have adequately mitigated and reduced flood towns to accommodate its growing population? impacts despite the high exposure to both coastal and inland flooding. The Dutch not only set the standard for flood reduction As part of a multi-disciplinary team each member will benefit from infrastructure and adaptation strategies, their cities serve as a working in a group of highly-motivated individuals that come together ‘posterchild’ for what a disaster resilient city should be. IJburg and as a team to find out the indicators of flood-resilient new towns. ways Almere are the new towns accommodating Amsterdam, the capital to cope with floods in developing/managing new towns. In general, Image to right: of The Netherlands. IJburg consists of artificial lands which have been the aim is to broaden our views and obtain a better understanding of Almere city on. raised from the IJmeer lake, and Almere is located on the reclaimed how to develop and manage newly developed communities to make it newly reclaimed land in the Ijsselmeer lake. resilient to floods, especially in the metropolitan area. land in the Lake IJssel, in the form This project focusses on exploring resilience to floods in new towns of a polder; and its in a various perspectives such urban planning, landscape architecture location relative to and infrastructure design, and governance. The results will lead us Amsterdam to find the planning/management strategies in developing resilient communities in the Houston-Galveston metropolitan area. HYDRAULIC INFRASTRUCTURE DESIGN INFRASTRUCTURE HYDRAULIC

112 113 Figure 1. Kayode Atoba The Amsterdam Metropolitan area in the Netherlands A REVIEW OF THE ADAPTIVE CAPACITY OF NEW TOWNS TO showing Almere and IJburg FLOOD RISK IN THE NETHERLANDS Source: Adapted from Zhou et al. (2015) CASE OF ALMERE AND IJBURG

Kayode Atoba is a Ph.D. Candidate, new towns continue to face the problems components of climate change, subsidence Department of Landscape Architecture and of uniformity in its demography, lack of and high river discharges are very high, thus Urban Planning, Texas A&M University, College both structural and cultural diversity, as putting new towns on reclaimed land in this Station, TX. well as failures socially, ecologically and area at high risk of flooding. However, the economically (INTI, 2017), all of which Dutch have an integrated system of both are poor characteristics of dealing with structural and non-structural flood mitigation Summary changing flood risk levels. Although some techniques and are renowned as the world Low-lying areas in coastal communities are studies have attempted to address the leader in dealing with flood hazards. Despite highly vulnerable to rising sea levels and challenges encountered by new towns this reputation, there are growing concerns Figure 2. coastal flooding. Those risks are further such as commuting problems from existing that planning institutions and even the Study area showing highlighted when there is rapid increase metropolitan regions (Hui & Lam, 2005), structure of the physical infrastructure need new and old towns in population and development in these spatial segregation resulting from planning to ‘climate proof’ their approach to flood risk where adaptive flood-prone areas. New Towns especially problems (Firman, 2004), and so on, there (van den Brink, Meijerink, Termeer, & Gupta, capacity indices are have been designed to cope with flood risk is no comprehensive discussions on the 2014). Additionally, although many cities in applied in delta regions as well as provide residence adaptive capacities specifically of new towns the Netherlands have a reputation for being for the rising population in metropolitan to flood hazards in past literature, neither is resilient, there has been no comprehensive communities where land is scarce. This paper there a comprehensive study on the adaptive empirical evaluation of the adaptive capacity assesses the adaptive capacity of new towns capacity and vulnerabilities of coastal new of these new towns to cope with flood risk. on reclaimed land in coping with flood risk in towns. coastal communities. The adaptive capacity This study will specifically evaluate the indicators used in the resiliency literature New Towns in coastal communities springing adaptive capacity of some new towns in the provides a methodological framework for from large-scale land reclamation activities Netherlands. The purpose of this project is measuring the social capacity, one of the and are even becoming much more to identify important factors in assessing the adaptive capacity dimensions, of selected prominent. Coastal communities with large adaptive capacities of these new towns to new towns in the Flevoland province of the metropolitan populations face the increasing changing flood risk. Netherlands. The results show similarities in pressure of housing the urban population the levels of social capacity for both old and and maximizing the amount of land available This project will answer four research new towns, however, interviews with local in these areas, thus taking advantage of questions: officials and engineers indicate differences dredging technologies to either create 1. What are important factors in measuring in structural and decision-making issues reclaimed land by elevating them above adaptive capacities of new towns to flood that could impact flood risk in Almere and sea levels or creating polders to drain areas risk? IJburg. Future research will improve on the that exist below sea levels. Clear examples 2. How have adaptive capacity as well as measurement of these indicators as well as of new towns across the world are those environmental, and institutional factors additional indicators for other dimensions of in the Flevoland region of the Netherlands, contributed to disaster resilience of Almere adaptive capacity across larger spatial and Palm Islands in Dubai, Kavala in Greece, Eko and IJburg? temporal scales. Atlantic in Nigeria and so on. These areas all 3. What flood mitigation and adaptation have different levels of flood risk and are thus strategies are used by new towns in the New Town Concept expected to have different adaptive capacity Netherlands? and New towns are gaining popularity in many to their respective flood risks, especially with 4. How do flood risk reduction strategies parts of the world. They were originally consideration to climate change. differ between new and old towns in the implemented to decongest metropolitan Netherlands? areas and provide self-sustaining Due to the Netherlands being located along communities to balance the pressure from the deltas of The Rhine and other rivers, their To determine these adaptive capacities, this 114 adjacent cities (Firman, 2004). However, vulnerabilities to sea level rise and other research use adaptive capacity indicators 115 Figure 3. from the resilience literature. In what capacities when they are robust, redundant, city less than 40 years old and still serves capacity as measured in past literature. Social Capital follows, this research presents an adaptive or rapidly accessible and thus able to offset a the important role of accommodating The indicators for the environmental indicators for the capacity definition and identification of new stressor, danger, or surprise.” (p. 136). The the rising population in the Amsterdam dimensions are derived from interviews with study area. the relevant dimensions as it relates to this emphasis here is on new stressors, surprise metropolitan area. This is evident in its hydrologists and planners of the new towns study. The research further applies existing and the ability of a system to cope with this. current population of about 195,000 and in the study area. Sherrieb, Norris, and Galea frameworks and attempts to measure some Climate adaptation strategies fall very well about 14,500 businesses (City of Almere, (2010) subsequently measured two of the of those indicators for Almere and IJburg. within these descriptions. This definition 2016). With this also comes the problems dimensions identified by Norris et al (2008) This presents a first step in understanding sees adaptive capacities as the availability that new towns face such as maintaining its by creating a set of indices to measure these adaptive capacity in these new towns. The of resources that are robust, redundant, function as a sustainable community, as well adaptive capacities at the county level. These research concludes by presenting preliminary accessible and represent varying elements as other planning and economic dilemma were more robust to being measured using sets of results and future study possibilities. of dynamic attributes (Norris, Stevens, (Thorgeirsdottir, 2010). publicly available population indicators data Pfefferbaum, Wyche, & Pfefferbaum, 2008). at the jurisdiction level while the other two Adaptive Capacity Although the city of Almere has implemented dimensions cannot be measured at this The concept of adaptive capacity has its Adaptive Capacity Dimensions effective planning tools, since it is on spatial scale. This research applies those origin in ecosystems literature and research Norris et al. (2008) identified what they reclaimed land, it is still vulnerable to indices in measuring the adaptive capacity of and is often described as the ability of a described as ‘networked resources’ from their flooding due to drainage problems from new towns in the study area. system to cope with stressors and shock definition of resilience as a set of networked the constructed polder. Despite these (Holling, 1973). The meaning and definition adaptive capacities. These are similar to challenges, the city of Almere has developed A third dimension of environmental and of resilience, vulnerability, and adaptive dimensions that have been identified by a dense network of surface and groundwater physical capacity was measured by creating to natural hazards has always generated other adaptive capacity literature. They management system combined with other a set of important indices as determined by controversies among researchers and led include: Information and communication, strategies of reducing imperviousness in the interviews with hydrologists and planners to the development and discussions on Economic development, Social Capital, city, which enables it to deal effectively with in the study area. The interviews revealed conceptual framework describing these Community Competence. Additionally, Ross excess runoff and subsequent flooding (Zhou, a set of adaptation strategies adopted by terms. However, there is still no consensus (2014) also highlight a set of dimensions Qu, & Zou, 2015). The selection of Almere as these cities. Other adaptation strategies have on what these terms explicitly represent for adaptive capacity to include social, a case study is also due to the fact that it also been recommended in past literature (Cutter et al., 2008). In fact, the definitions for community, economic, infrastructural and represents an ideal example of a new town such as examining the capacity of existing vulnerability, resilience and adaptive capacity institutional capital. These are summarized that incorporates multiple sustainability and infrastructures, flexibility in management has wide ‘plurality’ because it can be applied as the social, economic, environmental and urban planning values in both its design and practices, ecosystems adaptability, change to multiple systems, as a result, it leads to physical characteristics of communities management (Newman, 2009). Almere is also in human trends to adhere to natural Figure 4. varying understanding of the concept and which increases their ability to recover transitioning from a bedroom community systems, and educating the public and Overall standardized how it is applied across disciplines (Gallopín, from an event (Cutter et al., 2003). This to a self-sustaining urban area which makes improve environmental warning systems Social capital 2006). Some view resilience as major research will focus on the Social, economic it a suitable case study in addressing the (Klein, Nicholls, & Thomalla, 2003; Klein & z-score in part of adaptive capacity (Adger, 2006; and environmental dimensions of adaptive challenges of a changing community. Tol, 1997), all of which are addressed in the the selected Birkmann, 2006; Folke, 2006). while others capacity as defined in the cited literature. The second case study of Ijburg was also interview questions. These interviews will municipalities view adaptive capacity is a major part of constructed on artificial lands and has also inform future quantitative research in vulnerability (Burton, Huq, Lim, Pilifosova, Study Area adopted strict zoning laws, housing tenure measuring their adaptive capacities to flood & Schipper, 2002), and others still believe The initial analysis of the adaptive capacity requirements, and the use of urban design risk. This approach helps in understanding that both resilience, and adaptive capacity of new towns in the Netherlands will begin construction techniques such as amphibious the indices in the Dutch context that explains are all major components of vulnerability with the city of Almere and IJburg as a architecture. These approaches make it a the adaptive capacity of Almere and Ijburg (Gallopín, 2006). On the other hand, some case study. Almere is one of the main cities suitable comparison with flood resiliency in to coastal flooding. This research will also still view both terms as separate, but often in the Amsterdam metropolitan area. It is Almere as well as other coastal communities evaluate flood risk reduction at the city/ linked (Cutter, Boruff, & Shirley, 2003). Other in the province of Flevoland and borders around the world. community scale. definitions sees the aspect of change in the the cities of Lelystad and Zeewolde. The definition of resilience by identifying capacity Almere area is part of the Zuiderzee For measuring adaptive capacity indicators, Adaptive Capacity Indicators as the ability to deal with changes in the project which reclaimed vast amount three new towns in the Flevoland Province stability of the ecosystem (Gunderson, 2000). of land in the Ijsselmeer. Frevoland was were also selected, i.e. Almere, Dronten, ECONOMIC CAPITAL one of the three polders developed from and Lelystad, while Amsterdam and Table 1 (next page) shows the economic However, what distinguished adaptive the Zuiderzee project from 1959 to 1967 Rotterdam were selected as the old towns for capital indicators used by Sherrieb et al. capacity from these terms is the ability of a primarily for agriculture. However, due to comparison in this pilot survey. (2010). Although not used in this project, system to cope with changes in the system, the shortage of land for urban development because of data collection issues as well especially with reference to climate change in neighboring Amsterdam, the Dutch Methodology as the scale of study. However, these set of (Adger, 2005; Gallopín, 2006). In fact, government established the town of Almere This research applies a set of adaptive indicators will be used in future research on Norris et al (2008) summarizes it clearly by to house the rising population in the nearby capacity indicators from the economic, social how economic capital improve the capacity 116 arguing that “... capacities become adaptive city of Amsterdam. Presently, Almere is a and environmental dimensions of adaptive of communities to cope with flood risk. 117 Table 1: ECONOMIC CAPITAL SOCIAL CAPITAL cope with environmental stressors. The 3-tier principle of adaptation to changing climatic Economic capacity Although the economic indicators Dutch approach of dike protection, land use conditions. indicators used in Resource Level: highlighted by Sherrieb et al. (2010) inform planning and evacuation is being practiced. Norris et al (2008) Employment/population ratio additional research on new town adaptive The experts interviewed are confident in IJburg, the other new town, is elevated Median household income capacity, the focus on this phase of the the strategies in place for dealing with flood above sea level and does not deal with the M Ds/10,000 research is on the social capital of new risk for the area. They do acknowledge same vulnerabilities as Almere. Because of Corporate tax revenues/1,000 towns. Table 2 shows the adaptation of the that there is extreme dependence on the its proximity to Amsterdam and the design Percent creative class occupations indicators used in Norris et al’s research primary structural protection provided by the principle adopted, the land use density here and applying them to the context of the dikes which makes new evacuation studies is higher, limited green infrastructure and Resource equity: Netherlands. This project selected three new necessary in case of a dike failure. lower levels of soil subsidence. There have Income equity towns in the Netherlands in the Flevoland been adaptive measures in dealing with high Less than HS education (% AA minus White) region and two metropolitan communities in However, in terms of adapting to complex water levels such as constructing homes on the Netherlands as comparison. problems, there is still more to be done. For water so they can float during high water Resource diversity: example, with a rainfall holding capacity of levels. In this aspect, they can effectively Net business gain/loss rate Indicator Results just 60mm/hr., higher level of precipitation deal with sea level rise for structures directly Occupational diversity The set of primary social capital indicators combined with high river discharge as well adjacent the Ijssel Lake. Urban influence shows mixed results. Almere, Dronten and as high sea levels will overwhelm the current Lelystad are all new towns in the Flevoland design capacity. A major concern is that there However, despite higher levels of protection Region while Amsterdam and Rotterdam are are no decision-making structures in place and amphibious development, they still larger metropolitan municipalities in the north as to when and how much water should have to deal with inland flooding issues. and south Holland region. As seen in Figure be pumped into the North Sea to avoid The current capacity of IJburg and the 1, Migration rate are highest for Almere than inundation from both inland and coastal Amsterdam area for inland flooding is 70mm/ any other municipality. A closer look at the flooding. hr. There have been records of inundation Table 2: SOCIAL CAPITAL data however shows a reduction in migration to buildings and public infrastructure due to Social capacity rate since 2000 due to the challenges facing The respondents identified subsidence as a high rainfall events which exceed the current indicators adapted Sherrieb et al. (2010) This Project Scale Source new towns in the Netherlands. There is a threat to the adaptive capacity of this new capacity. That has ignited additional rainproof from Sherrieb et al. relatively even distribution of public and town. Because of the composition of the soil measures of floodwater retention at the (2010) and indices Social Support: Social Support: sports facilities irrespective of whether the used in reclaiming the land, subsidence of parcel level. used in this project 2-parent + children to 2-parent & 1-parent + Not Available at municipal scale municipality is a new town or not. Voting about 6cm every year has been recorded. children and religion data also show little variation. There are even visible signs of subsidence Conclusion On the other hand, the percentage of around the city such as sinking roads, In summary, this case study visit has been Social participation: Social participation: historical organizations and facilities are buildings and critical infrastructure. This able to identify a pilot set of adaptive Number of arts/sports organizations/10,000: Sports Ground (land use) Municipal CBS different for these municipalities. Rotterdam becomes even more complex with changing capacity indicators as it affects new towns. Number of civic organizations/10,000: Public institutions (land use) Municipal CBS and Amsterdam show significantly higher climatic conditions. And yes, the Dutch do Additional work is ongoing on how to apply Voter percent presidential election: City Council Election (2015) Municipal Kies Raad percentage of historical values than the believe in Climate change and sea level rise. relevant adaptive capacity dimensions and Religious adherents/1000: Religious Adherents Municipal CBS new towns of Almere, Dronten and Lelystad the indicators for new towns. Currently, combined. Because the town is just over 40 years old, according to a set of indicators by the Community Bonds: Community Bonds: there are social issues like the lack of general European Environment Agency, the Flevoland Net migration rate/1,000 1990-2016 Net migration rate/1,000 1990-2016 Municipal CBS Interview Results social cohesion among the residents. This region where Almere is located has a high Property crime rate (inverse) Not Available at municipal scale In terms of Physical capacity, Almere is being addressed by increased emphasis aggregate impact of climate change, low is below sea level and highly exposed on promoting diversity in the city. Because capacity and potentially vulnerable to climate Social History Social History to coastal flooding, however, there are this is a new town with very little history, change. Identifying a set of indicators at Not Measured in this study Historical Monuments per 1,000 Municipal CBS dikes all around the city in addition to building social capital is a major concern. the community scale with emphasis on new comprehensive drainage systems as well as The city is also trying to stay economically towns will help highlight problematic areas in other primary defense structures in the area. sustainable rather than just a bedroom adapting to climate change It is my hope that During high precipitation events and river community for Amsterdam. There is a lot identifying these indicators and quantitatively discharge, excess floodwater is pumped into of pressure to attract residents to Almere. measuring them will be beneficial to new Markermeer Lake and further pumped into This is a challenge to maintaining their green towns and newly incorporated communities the North Sea with high capacity pumping infrastructure and strict spatial planning that deal with similar flood risks in the US as stations. These pumping stations can also approach. For example, there is currently a well as other coastal towns around the world. pump in advance of heavy rainfall event to do-it-yourself program where people can increase the holding capacity of the polders. buy lots of land and are not subject to the Future Research Proposal Although just about 40 years old, the built strict top-down planning laws and can build The sample size in this pilot study makes 118 environment in Almere has been designed to whichever way they want. This begs the it difficult to carry out empirical tests, but 119 Figure 5.(below left) Figure 7. provides great insights into the data needs analysis of section 404 wetland permitting in Part B: Environmental Hazards, 5(1), 35- Inference from Future Research and refinement of the research questions. It Texas and Florida: Thirteen years of impact 45. respondent’s opinion extension of new also provides an opportunity to increase the along the coast. Wetlands, 28(1), 107-116. Klein, R. J., & Tol, R. S. (1997). Adaptation to of adaptive capacity town adaptive spatial and temporal scale of the research. Brody, S. D., Zahran, S., Maghelal, P., Grover, H., climate change: Options and technologies. and possible future capacity Source: Strategies of increasing the sample size & Highfield, W. E. (2007). The rising costs Institute for Environmental Sciences, Vrije dimensions to be International New include extending the sample to include of floods: Examining the impact of planning Universiteit, Amsterdam. measured (Almere) Town Institute all new towns in the Netherlands, improve and development decisions on property Newman, M. (2009). Almere new city, matching techniques for comparative damage in Florida. Journal of the American Sustainable city, Ideal city? An urban analysis of new and old towns, comparison Planning Association, 73(3), 330-345. Burton, morphological analysis of the newest Dutch Figure 6.(below right) with other new towns in the US with varying I., Huq, S., Lim, B., Pilifosova, O., & Schipper, city, 21, 13-20. Inference from spatial, infrastructure, social-demographic E. L. (2002). From impacts assessment Norris, F. H., Stevens, S. P., Pfefferbaum, B., respondent’s opinion and institutional characteristics. Applying to adaptation priorities: the shaping of Wyche, K. F., & Pfefferbaum, R. L. (2008). of adaptive capacity all these improve the results and creates a adaptation policy. Climate policy, 2(2-3), Community resilience as a metaphor, theory, and possible future better insight into the capacity of new towns 145-159. Cash, D. W., Adger, W. N., Berkes, set of capacities, and strategy for disaster dimensions to be to cope with flood risk. As a research agenda, F., Garden, P., Lebel, L., Olsson, P., . . . Young, readiness. American journal of community measured (IJburg) I will proceed with creating a comprehensive O. (2006). Scale and cross-scale dynamics: psychology, 41(1-2), 127-150. research proposal to fund this larger scaled governance and information in a multilevel Ross, A. D. (2014). Local disaster resilience: research as well as complete additional pilot world. Ecology and society, 11(2), 8. Administrative and political perspectives (Vol. surveys to better improve the results of this Cutter, S. L., Barnes, L., Berry, M., Burton, C., 9): Routledge. research. Evans, E., Tate, E., & Webb, J. (2008). A place- Sherrieb, K., Norris, F. H., & Galea, S. (2010). based model for understanding community Measuring capacities for community Additionally, in collaboration with multiple resilience to natural disasters. Global resilience. Social Indicators Research, 99(2), disciplines, future research will integrate environmental change, 18(4), 598-606. 227-247. other scales of flood mitigation at the parcel, Cutter, S. L., Boruff, B. J., & Shirley, W. L. Thorgeirsdottir, H. (2010). New town subdivision and district level. A multi- (2003). Social vulnerability to environmental development: a new approach in planning for scale analysis is essential because local hazards*. Social science quarterly, 84(2), new towns: a case study of urban growth of scales addresses site-level problems while 242-261. Almere, The Netherlands. regional scales addresses environmental Firman, T. (2004). New town development in van den Brink, M., Meijerink, S., Termeer, C., & conservation of shared resources as well as Jakarta Metropolitan Region: a perspective of Gupta, J. (2014). Climate-proof planning for better growth plans through regional land spatial segregation. Habitat International, flood-prone areas: assessing the adaptive use management (Foster, 2001). Studies have 28(3), 349-368. capacity of planning institutions in the also recommended tracking of ecological Folke, C. (2006). Resilience: The emergence Netherlands. Regional environmental change, disturbances on a broader regional and of a perspective for social–ecological systems 14(3), 981-995. spatio-temporal scale rather than on a site- analyses. Global environmental change, 16(3), Zhou, Z., Qu, L., & Zou, T. (2015). Quantitative by-site basis since flood impacts crosses sites 253-267. analysis of urban pluvial flood alleviation by or jurisdictional boundaries (Brody, Davis, Foster, K. A. (2001). Regionalism on purpose. open surface water systems in new towns: Highfield, & Bernhardt, 2008; Brody, Zahran, Gallopín, G. C. (2006). Linkages between Comparing Almere and Tianjin eco-city. Maghelal, Grover, & Highfield, 2007). It has vulnerability, resilience, and adaptive capacity. Sustainability, 7(10), 13378-13398. also been found that systems that address Global environmental change, 16(3), 293-303. multiple scales are more successive in Gunderson, L. H. (2000). Ecological identifying problems and seeking ecologically resilience—in theory and application. Annual sound solutions (Cash et al., 2006). review of ecology and systematics, 31(1), 425- 439. Holling, C. S. (1973). Resilience and stability of References ecological systems. Annual review of ecology Adger, W. N. (2005). Governing natural and systematics, 1-23. resources: institutional adaptation and Hui, E. C., & Lam, M. C. (2005). A study of resilience’. Adger, W. N. (2006). Vulnerability. commuting patterns of new town residents Global environmental change, 16(3), 268-281. in Hong Birkmann, J. (2006). Measuring vulnerability Kong. Habitat International, 29(3), 421-437. to natural hazards: towards disaster resilient Klein, R. J., Nicholls, R. J., & Thomalla, F. societies. (2003). Resilience to natural hazards: How Brody, S. D., Davis, S. E., Highfield, W. E., & useful is 120 Bernhardt, S. P. (2008). A spatial-temporal this concept? Global Environmental Change 121 NSF PIRE - 2017 8

prairie. Figure 1a depicts the current land use of Cypress Creek, and 1b depicts projected conditionsNSF PIRE in - 2040.2017 8

Figure 1a. Avantika Gori Cypress Creekprairie. 2010 Figure 1a depicts the current land use of Cypress Creek, and 1b depicts projected land use QUANTIFYING IMPACTS OF URBANIZATION ON FLOOD RISK conditions in 2040. UNDER CONTRASTING MANAGEMENT STRATEGIES

A CASE STUDY OF ALMERE, NETHERLANDS, AND CYPRESS CREEK, HOUSTON, TEXAS

Avantika Gori is a Masters Student, Depart- Background and Motivation regions can inform urban planners about the ment of Civil & Environmental Engineering, Urban population growth and land effectiveness of different overland drainage Rice University, Houston, Texas. development in the last half century has infrastructure and about the impact on flood occurred rapidly across the U.S. Estimates risk resulting from different policy plans or from the U.S. Census Bureau suggest that development criteria. Abstract between 1960 and 2000 there has been a This study evaluates the overland drainage 130% increase in extent of urban areas (Alig Research Questions management practices in the city of Almere, et al, 2004). While population growth has This study aims to answer the following Netherlands compared to the Cypress been substantial during this period of time, questions: Creek watershed in Houston, TX. These data from the Natural Resources Inventory How do contrasting overland drainage sites represent contrasting strategies: demonstrates that land development management strategies impact rainfall- new development in the city of Almere is has been occurring at a faster rate than induced flood risk in Almere, Netherlands completely planned by city and regional population growth, suggesting that urban and Houston, TX? government, while development in Cypress sprawl has been a major contributor to the And what is the impact of future Creek has occurred with virtually no loss of natural and agricultural lands (Alig et development scenarios on flood risk under zoning laws or governmental interference. al, 2004). these two types of drainage infrastructure? Additionally, on site retention of excess runoff has traditionally been practiced in many In coastal counties across the US, growth In order to answer these questions, this study Dutch cities, while historical development has been even more dramatic: between will first present a brief review of land use Figure 1b. in Houston has not been subjected to 1980 and 2003 the population of coastal policy and overland drainage management Cypress Creek 2040 such restrictions. In order to evaluate the counties increased by 33 million (Crossett strategies adopted in the Netherlands land use projections. differences in these planning strategies under et al, 2004). In the state of Texas the fastest and in Harris County. These policies and future development scenarios, this study growing coastal area is Harris County, infrastructure systems will then be modeled utilizes a physics-based hydrologic computer which contains the City of Houston and its using a physics-based hydrologic model in model to simulate the rainfall-runoff process. surrounding suburbs. This county has already order to characterize existing rainfall-induced Changes in runoff volume and peak flow experienced massive population growth, and flood risk in both case study areas. Next, are computed under future development is projected to continue rapidly growing for future land use projections will be modeled in conditions for both site areas, and results the next several decades (HGAC, 2015). This both areas to assess the potential increases indicate that without incorporation of on-site increase in population has yielded massive in risk (as measured by increased peak flows detention both Almere and Cypress Creek conversions of natural land to impervious and runoff volumes). are expected to increase peak flow by up to area, which has resulted in numerous 56% and 55% and increase runoff volume by environmental and natural hazard impacts. Land Use Planning History up to 47% and 26% respectively. However, In order to remediate the negative impacts In the Netherlands, land use planning has Figure 1: (a) Cypress Creek 2010 land use (top); (b) Cypress Creek 2040 projections (bottom) under a future scenario that incorporates on- of unchecked urbanization, it is important to been a well-established policy since the turn site retention in Almere, future development understand the interactions between where of the 20th century. Early laws allowed the is expected to have almost no impact on development occurs, how it occurs (i.e. national government to designate areas of peak flows or runoff volumes. These results under what kind of regulations and design new development and renovate run-down indicate that on-site retention practices criteria), and the resulting impacts on flood areas of the country (Halleux et al, 2012). 2.1.2 City of Almere in Netherlands may be able to effectively mitigate potential risk. The infrastructure and management This paved the way for the development Figure 1: (a) Cypress Creek 2010 land use (top); (b) Cypress Creek 2040 projections (bottom) increases in flood risk due to future systems of the Netherlands, a global leader of a thorough land-zoning system, and for The City of Almere is located in the Zuid Flevoland, a polder east of Amsterdam. Due to development. Future work in this area should in flood management and sustainable most of the 20th century the Netherlands focus on quantifying impacts to floodplain development, can serve as a prime case pursued a policy of “pro-active operational extent due to future development in addition study region that can be compared to Harris planning” (Halleux et al, 2012). This strategy 122 this proximity, the city population has grown rapidly, and is expected to grow to eventually to increases in peak flow and volume. County. A comparative analysis of these two entails pro-actively designating certain areas 123 2.1.2 City of Almere in Netherlands accommodate 350,000 inhabitants. The city relies on a dense network of small overland canals to The City of Almere is located in the Zuid Flevoland, a polder east of Amsterdam. Due to store and transport overland runoff during rain events, as well as two larger canals called the this proximity, the city population has grown rapidly, and is expected to grow to eventually high and low canal. Additionally, several main pumps remove water from the high and low canal accommodate 350,000 inhabitants. The city relies on a dense network of small overland canals to and into Lake Ijssel. The pumps are not modeled for this analysis, since this study seeks to store and transport overland runoff during rain events, as well as two larger canals called the isolate the impacts of differences in overland drainage infrastructure management as well as high and low canal. Additionally, several main pumps remove water from the high and low canal development policies. Although the city is already highly developed, there have been significant and into Lake Ijssel. The pumps are not modeled for this analysis, since this study seeks to isolate the impacts of differences in overland drainage infrastructure management as well as development policies. Although the city is already highly developed, there have been significant NSF PIRE - 2017 9

areas of green space preserved. Figure 2a shows the current land use, while 2b shows future projected development in the city.

Figure 2a that will become developed under future Overland Drainage Management detention that accommodates up to 60 Almere: 2010 Land population growth conditions. This method In order to understand the overland drainage mm/hr, which corresponds to the 100-year Use. of planning limits urban sprawl because infrastructure in the Netherlands and the intensity (Spaan, 2017). future development areas are carefully drainage criteria for new development, a planned, rather than allowing piecemeal series of interviews were conducted with city Developers often build “wadis”, which are development to occur. However, since the planners, civil engineers, and hydrologists. drainage ditches that remain dry during 1990’s, the Netherlands has shifted focus This method of research was chosen since normal conditions, but are used as storage away from controlled expansion to policies most of the policy documents are written during heavy rain events (Balkema, 2017). that encourage development compaction (i.e. in Dutch, and lengthy translations were not Aside from on-site detention policies, densification of existing urban areas). feasible to obtain. In Houston, the overland there are also more general policies that drainage is overseen both by the municipal encourage allocation of green space within The new town of Almere, founded in 1977, government, and the Harris County Flood developed areas. These green areas are seen serves as an ideal example of both pro- Control District (HCFCD). To understand as crucial elements for the aesthetics of active planning and compaction planning Houston’s specific drainage management the city, environmental health, and drainage (Duivesteijn, 2009). Almere was planned by approach, both the City of Houston management. Many parts of the Netherlands the national government in the 1950’s-60’s Stormwater Guidelines and the Harris County are built on porous media like sand, so to accommodate population growth in Criteria Manual were analyzed (HCFCD, 2010; allocating green space allows a high degree and around the city of Amsterdam, and COH, 2013). of infiltration of rain water. was initially designed to contain 250,000 inhabitants (Duivesteijn, 2009). The city In general, cities in the Netherlands rely on While cities in the Netherlands have was built on reclaimed lands, and its entire a dense network of overland canals to store developed extensive overland canals to land footprint was allocated by the national and transport overland runoff during rain convey stormwater through the city, the government. However, in the past 10-15 events. Since many urban areas are located City of Houston has instead pursued a years it has become clear that Almere will below sea level, and are protected by ring combination of underground storm sewer need to adapt its current land use in order levees, water from the canals must eventually pipes and large regional overland channels to accommodate an additional 100,000 flow toward pumping stations, which pump known as bayous. A bayou can be defined inhabitants. Thus, although Almere was the water out of the polder. In advance of as a generally slow-moving stream that is initially conceived under a vision of controlled large rainfall events, canals can pro-actively primarily fed by rainwater (Sebastian & Gori Figure 2b expansion, it must now meet future be pumped to allow greater rainwater 2018). However, due to the mild slopes of Almere: Future population growth by instituting policies of storage from overland runoff (Balkema, the watersheds in Harris County, as well as developed projects compaction. 2017), and water levels in the canals can be the high 100-year rainfall magnitude (13.2 decreased up to 5cm (Visser, 2017). However, in. per 24hrs), it is not feasible to design the In contrast to the tight land regulations of the maximum pumping rate during a rainfall storm sewer pipes to convey the 100-year the Netherlands, decision-makers in the event can only remove 13 mm/hr from flow. Instead, the City of Houston stipulates city of Houston (and Harris County) have the canals, so excess overland flow must that these underground conduits should traditionally pursued a much more laissez- be stored in the canals (Visser, 2017). The be “designed to convey less intense, more faire approach to land development. In fact, government regulates the normal water levels frequent rainfalls” (COH, 2013). In fact, Houston is the only major city in North in these drainage canals so that a minimum minimum design criteria state that the pipe America without land-use zoning laws of 1.2 m is available for rainwater storage network must only convey a 2-year flow (Qian, 2010). Instead, planning decisions are (Visser, 2017). (COH, 2013). For rainfall events greater than a typically made by corporations or individuals 2-year magnitude, the city relies on overland in the private sector (Fisher, 1989). Houston In addition to these regulations and policies runoff into the bayous as the primary is also unique because it has experienced that govern canal management, new drainage mechanism. steady population growth starting in the development in the Netherlands is also early 1900’s until now, and is projected to subject to drainage criteria and restrictions. Land Use Impacts on Flood Risk experience a population increase of over Many areas of the Netherlands operate under The density, extent, and spatial configuration 2.2 million between 2010-2040 (HGAC, a “water neutral philosophy”, stipulating that of developed land have the potential to 2016). High growth rates coupled with lax new development should not result in any greatly alter the hydrologic response of the development restrictions have resulted in additional overland flow to the municipal encompassing watershed or drainage area. dramatic rates of urban sprawl. In 1900 the canals (Spaan, 2017). On-site detention The presence of developed land can increase city of Houston was 9 sq. miles and by 1980 requirements are common methods the peak flows, overall volume, and shorten it had grown to over 556 sq. miles (Fisher, implemented to offset impacts from new the time to peak flow during large rain events. 1989). development. In the new town of Ijburg, There have been many studies documenting 124 developments should incorporate on-site these impacts from development (Leopold, 125 Figure 2: (a) Almere 2010 land use (top); (b) Almere future developed projections (bottom)

Table 1. LAND COVER DESCRIPTION MANNING’S n IMPERVIOUS % 1968; Bhaduri et al, 2000; Surya & Mudgal, Cypress Creek and Little Cypress Creek. cell contains parameters that account for Roughness and Developed, open space 0.04 0,1 2011; Singh & Singh, 2011). Specifically in the Cypress Creek ultimately flows into the San elevation, soil type, and land cover. Grid cells Impervious values Developed, low intensity 0.07 0.35 Houston region there have been multiple Jacinto River, which empties into Galveston can either be classified as overland or channel based on land Developed, medium intensity 0.07 0.6 studies evaluating the potential for land use Bay. During normal conditions, these channels cells, and rainfall-runoff calculations are cover Developed, high intensity 0.04 0.9 change to exacerbate flood risk. Two recent contain very lows flows (less than 50 ft3/s), conducted at each grid cell. Water is routed Barren land 0.01 0 studies have utilized historical streamflow but during high-intensity rain events they between overland cells via the Kinematic Deciduous forest 0.36 0 data and historical land use conditions may transport over 10,000 ft3/s. Wave Analogy (KWA), and Modified Puls Evergreen forest 0.32 0 to correlate increasing development with routing was selected as the channel routing Mixed forest 0.40 0 increasing runoff (Khan, 2005; Olivera & The Cypress Creek watershed is partially method for this study due to the relatively Shrub/scrub 0.40 0 Defee, 2007). Another study examined developed, with most of the residential and mild slope of the watershed. A full description Grassland/herbaceous 0.37 0 the impact of spatial configuration of commercial development confined to the of the Vflo® model formulation and derivation Pasture/Hay 0.33 0 development on flood losses and found that southeast portion of the watershed. The of the KWA is documented in Vieux & Vieux Woody wetlands 0.09 0 high intensity land development increases upstream (northwest) portion primarily (2002). Infiltration is modeled using the Emergent herbaceous wetlands 0.18 0 flood damages in adjacent properties (Brody consists of agricultural lands, natural Green and Ampt Equation, which depends et al, 2014). prairie, and some wetlands. However, future on soil properties of hydraulic conductivity, development projections of the HGAC wetting front capillary pressure head, and There has been less research of this nature suggest that by 2040 development could effective porosity. CURRENT FUTURE in the Netherlands, since the primary flood spread significantly across the watershed, and Table 2. Location Drainage area (km2) Avg Rough Avg Impery Avg Rough Avg Impery concerns stem from storm surge events and result in the loss of large tracts of farmland Vflo® models have been successfully Land Use change 1 20.44 0.15 0.16 0.12 0.32 potential levee failures. However, a recent and prairie. Figure 1a (previous page) depicts developed and utilized to model the overland summary for each 2 81.56 0.13 0.32 0.12 0.37 comparative study of Tianjin Eco-City, China the current land use of Cypress Creek, and 1b hydrologic response in numerous watersheds drainage area 3 4.01 0.13 0.07 0.11 0.18 and Almere, Netherlands found that in highly depicts projected conditions in 2040. in the Houston region: Vieux & Bedient 4 27,25 0.14 0.05 0.08 0.29 populated urban areas a densely distributed (2004), Torres et al (2015), Sebastian (2017). 5 10.08 0.13 0.01 0.09 0.23 surface water network is needed to alleviate City of Almere in Netherlands Since distributed hydrologic models are able 6 4.56 0.13 0.02 0.09 0.21 impacts of overland runoff from impervious The City of Almere is located in the Zuid to represent spatially-varying hydrologic surfaces (Zhou et al, 2015). Flevoland, a polder east of Amsterdam. parameters, Vflo® is a powerful tool for Due to this proximity, the city population modeling the cumulative impacts of land cover Modeling Methods has grown rapidly, and is expected to changes. Previous studies have demonstrated Figure 3a (below The distributed hydrologic model Vflo® grow to eventually accommodate 350,000 Vflo®’s ability to evaluate LID features, left). Almere: Vflo® is used to represent overland drainage inhabitants. The city relies on a dense development scenarios, and watershed model domain conditions and overland channels in Almere, network of small overland canals to store evolution through time: Juan et al (2017), Netherlands and Houston, TX. For each and transport overland runoff during rain Doubleday et al (2013), Fang et al (2010). Figure 3b. (below case study area a 100-year design storm events, as well as two larger canals called the right) Cypress Creek: in modeled in Vflo® and flow hydrographs high and low canal. Additionally, several main Data Collection and Processing Vflo® model domain are presented at the watchpoints of each pumps remove water from the high and low The Vflo® model set up relies on high-quality site (there are three watch points point in canal and into Lake Ijssel. The pumps are not input data of elevation, land use, land cover, the Cypress Creek watershed and six at the modeled for this analysis, since this study and soil type. Elevation information for Almere site). Next, future land use scenarios seeks to isolate the impacts of differences Cypress Creek is obtained from USGS National are developed using future projections in overland drainage infrastructure Elevation Database. This data is obtained as for each site and two possible mitigation management as well as development policies. a seamless 10m resolution raster, deriving scenarios. Impacts of each scenario are Although the city is already highly developed, from Lidar point cloud information. Elevation quantified at the watch points in terms of there have been significant areas of green information for the Netherlands is obtained change in peak flow and change in volume. space preserved. Figure 2a shows the current from the Actueel Hoogtebestand Nederland Finally, differences in results between Almere land use, while 2b shows future projected (AHN) in 0.5m resolution, which is also derived and Houston are discussed in the context of development in the city. from Lidar point clouds. This high-resolution their respective management strategies. data was modified slightly in ArcGIS in order Hydrologic Modeling Method: Vflo® to fill sinks in the DEM, which can impact the Cypress Creek Watershed in Houston, TX Vflo® is a physics-based, fully-distributed performance of the Vflo® model. The Cypress Creek watershed is located in hydrologic model developed by Vieux that northwest Harris County, TX. It contains a solves conservation of mass and momentum Land use data is obtained for Cypress current population of around 350,000 and equations using a finite-element approach Creek from the USGS National Land Cover encompasses a drainage area of 267 mi2 in order to model the rainfall-runoff process Database (NLCD). The most recent release of (692 km2). This watershed relies primarily (Vieux & Vieux, 2002). The watershed domain the NLCD data is from 2011, and this land use 126 on two large bayous for overland drainage: is represented in grid cell format, and each serves to represent the “current conditions”. 127 Figure 3: (a) Almere Vflo® model domain (top); (b) Cypress Creek domain (bottom)

Figure 4. Figure 5. Flow hydrograph Flow hydrograph comparison for comparison for Almere watch points. Cypress Creek watch points.

Location Op Op Op Vol Vol Vol Table 3. Current Future Future+R Current Future Future+R Peak flow (m3/s) and 1 7.2 9.4 9.1 403671 504726 485431 Volume (m3) for each 2 34.5 35.0 34.8 2171229 2278263 225736 scenario 3 2.8 2.9 2.8 99637 110188 96733 4 4.0 5.3 3.5 397345 585353 375541 5 2.3 3.2 2.4 178444 246323 181203 6 0.9 1.4 1.0 84113 112179 84826

Location Current to Future Current to Future+R Current to Future Current to Future+R Table 4. % Change Op % Change Op % Change Vol % Change Vol Percent change in 1 31.4 26.7 31.4 20.3 Op and Volume 2 1.5 0.9 1.5 3.7 between future 3 1.3 0.7 1.3 -2.9 scenario’s and 4 33.2 -11.4 33.2 -5.5 current conditions 5 38.8 1.3 38.8 1.5 128 6 56.2 4.4 56.2 0.8 129 Figure 6. Future land use is obtained from HGAC Almere model has 60m grid cell resolution, RESULTS The peak flow (Qp) and volume of each Correlation between projections for the region, and clipped to the while the Cypress model has 91m resolution. hydrograph are summarized in table 5. percent increase in Cypress Creek watershed. Current land cover The larger cells in the Cypress model are Land Cover Changes: Almere The change in peak flow (Qp) in m3/s and

volume (left) and Qp information for Almere is obtained from the necessary due to the substantially larger The following metrics for each watch point the change in volume in m3 is summarized (right) vs change in Publieke Dienstverlening op de Kaart (PDOK), drainage size of the watershed. All input in the Almere model were computed in for both future scenarios in table 6. imperviousness. and is dated to 2012. The future development data is resampled to match the resolution order to understand the magnitude of projections for the city were obtained by of each Vflo® model. Six watch points were land use conversion within each drainage Discussion Mr. Stoefels, a planner for the city. Vflo® chosen for the Almere model in order to area: drainage size, current average Across sites and drainage points, future land represents land use/cover (LULC) information capture all the drainage areas that experience overland roughness average impervious use conditions are shown to increase both using two parameters: Manning’s roughness land use conversion under the projected percent, and future average roughness and peak flows and runoff volume. For the Almere and impervious percent. Manning’s roughness conditions. Since the model does not have imperviousness. site, peak flow increases range from 1.3% up is a parameter that accounts for frictional one outlet for the entire city, it is necessary to 56%. These increases in peak flows are in losses between overland flow and the to examine multiple smaller outlets in order In each of the sub-areas, the average part driven by the increase in imperviousness ground surface. Concrete or developed areas to understand the overall impacts of land use roughness decreases under future of the drainage area. As shown in figure 5, generally have lower roughness, resulting conversion. For the Cypress Creek model, development and the average increases in peak flow are correlated with in less frictional losses, and consequently three locations are chosen along the main imperviousness increases. This makes sense, increasing impervious area. However, this greater speed of overland flow. On the other stem of the creek. These were chosen in order because conversion of agricultural land to factor alone cannot explain the observed hand, natural vegetation has a high roughness to understand how flows change across the developed space would lower the surface results. In addition to the magnitude of value, which slows down overland flow and watershed, and understand if flow increases friction and increase the extent of concrete land use change, the drainage path also attenuates the peak flow. Impervious percent are attenuated as they move downstream. or pavement areas. The drainage area sizes determines increases in peak flow. For accounts for the fraction of the area that is range from 4 km2 to 82 km2. These changes example, at location 1 there is a substantial covered with impervious surface, and thus Future Land Use Scenarios are summarized in table 2. increase in peak flow (34%) since this watch unable to be used for infiltration. Again, Two future land use scenarios are considered point is just downstream of the proposed areas of higher development have greater for the Almere region. The baseline scenario Overland Peak Flow and Volume Impacts: development. However at location 2, which impervious percent, and thus increase the assumes no development mitigation, while Almere is much further downstream from location volume of overland runoff compared to scenario two considers on-site retention for At each of the six watch points flow 1, there is a very small increase in peak flow. natural areas. For each land use category in new development. Retention is commonly hydrographs were calculated under current This suggests that as a flood wave travels the NLCD data, roughness values are derived used mitigation strategy that requires conditions, future conditions, and future downstream, the increase in peak flow can using Kalyanapu (2010), and impervious developed parcel to store a certain amount conditions with retention mitigation. The get attenuated due to frictional losses as well percent values are specified per NLCD of rainwater in order to reduce overall strain results are shown in the graphs presented in as incoming overland flows that can outweigh guidance. Table 1 shows the roughness and on the overland drainage system. For this figure 4 (next page). the increased peak flow from upstream. impervious values utilized in the model. The analysis, retention is set at 20mm/hr, which The peak flow (Qp) and volume of each land use categories for the Almere region was based on both conversations with hydrograph are computed and summarized A similar trend is observed in the Cypress are translated and re-categorized using Dutch city planners as well as the infiltration in table 3 (next page). Creek watershed. Location 1 has the highest Figure 5: Correlation between Percent increase in volume (top) and Qp (bottom) vs changeNLCD in classifiers. This allows roughness and capacity of the underlying soil in Almere. The change in peak flow (Qp) in m3/s and the increase in peak flow (55.3%), but this impervious percentages to be assigned to For the Cypress Creek region, no mitigation change in volume in m3 is summarized for increase is attenuated substantially by the each land class. is considered since historically development both future scenarios in table 4 (next page). time the flood wave reaches location 3 (8% has not been subjected to on-site retention increase in peak flow). The results of this Soil type data was obtained for Cypress Creek criteria. Although new guidelines for the Land Use Change Correlation with Increasing peak flow analysis suggest that land use Table 5. Location Op Op Vol Vol from the Texas Natural Resources Information Cypress region have specified some level of Qp and Runoff Volume changes may produce the greatest increases Peak flow (m3/s) and Current Future Current Future System and compiled by the Natural Resource required mitigation, this study focuses on In order to understand the impact of in flood risk in areas immediately downstream Volume (m3) for each 1 252.3 391.8 31901637 38903916 Conservation Service of the USDA. Infiltration historical development practices, and their increasing urban development on overland of the new development. From an scenario 2 630.5 875.7 61695031 77877061 is modeled using the Green & Ampt equation, impacts on flood risk. runoff, graphs were produced comparing infrastructure standpoint, the existing canal 3 1117.1 1207.3 89620990 110009367 which requires parameters of hydraulic average change in imperviousness at each capacity in Almere or the existing capacity conductivity, porosity, and wetting front Design Rainfall Storms watch point with percent change in Qp and of Cypress Creek in undeveloped regions capillary pressure. These values were derived In both regions a 100yr design rainfall volume. These results are presented in figure 5 may not be able to absorb the impacts of for each soil type according to Rawls et al is used to assess flood risk and relative (next page). future development. However, in areas further (1983). Detailed soil information for Almere changes between land use scenarios. This downstream that have larger contributing was also available through the PDOK, and soil corresponds to 315mm in 24hrs for Cypress Overland Peak Flow and Volume Impacts: drainage areas, channel capacity may be Table 6. Location Change to Future % Change to Future % type data was translated in order to utilize Creek and 60mm per 1hr in Almere. However, Cypress Creek sufficient to accommodate the relatively Percent change in Qp Change Qp Change Vol parameter values from Rawls et al (1983). since the 100yr rainfall for Cypress Creek At each of the three watch points flow small percentage increase in peak flows. and Volume between 1 252.3 252.3 is significantly higher than Almere, a more hydrographs were calculated under current future scenario and 2 630.5 630.5 Figure 3 shows the Vflo® model domains severe storm of 120mm in 2hrs is considered conditions and future conditions. The results In the Almere site, future development 130 current conditions 3 1117.1 1117.1 for Almere (a) and Cypress Creek (b). The for the Almere site. are shown in the graphs presented in figure 6. results in greater runoff volume at all watch 131 Figure 7. point locations. Table 4 shows the percent Conclusions and Future Work Doubleday, G., Sebastian, A., Luttenschlager, Policy, Criteria, and Procedure Manual (2010). Flood damage along increase in runoff volume for each watch This study has aimed to understand how T., & Bedient, P. B. (2013). Modeling Harris County Flood Control District. Cypresswood near point in the model domain, and these values land use changes impact peak flow and Hydrologic Benefits of Low Impact Rawls, W. J., Brakensiek, D. L., & Miller, N. Stuebner Airline in vary greatly. Figure 5 shows that increasing runoff volume under contrasting drainage Development: A Distributed Hydrologic (1983). Green-Ampt Infiltration Parameters northwest Houston runoff volume is highly correlated with infrastructure and management strategies. Model of The Woodlands, Texas. Journal of from Soils Data. Journal of Hydraulic in April 2016. increasing impervious area in the drainage While the Netherlands has a long history of the American Water Resources Association, Engineering, 109(1), 62-70. (Photo courtesy area. Watch points that have a high increase land use planning, the city of Houston has 49(6), 1444–1455. doi:10.1111/jawr.12095 Sebastian, A., & Gori, A. (2018). Flood Cypress Creek in impervious area also have a high increase primarily relied on private entities to drive Duivesteijn, A. (2009). Draft Structural Control Policy and Risk Management in Cultural District) in runoff volume. Although increases in development trends and patterns. This has Vision Almere 2.0: Summary. Environmental the United States. In Chapter 12, Hydrology runoff volume do not always result in higher resulted in substantial increases in riverine Planning, Municipality of Almere. and Floodplain Analysis, 6th ed. by Philip B. flood risk, in Dutch polders runoff volume flood risk in the Houston region, but this Fang, Z., Zimmer, A., Bedient, P. B., Robinson, Bedient, Wayne Huber, & Baxter Vieux. Upper can be an important consideration since pattern has not been observed in the new H., Christian, J., & Vieux, B. E. (2010). Using a Saddle River, NJ: Prentice Hall. eventually excess surface runoff must be town of Almere. Incorporation of retention Distributed Hydrologic Model to Evaluate the Sebastian, A. (2016). Quantifying Flood pumped out of the polder. However, canals mitigation has been shown in this study to Location of Urban Development and Flood Hazard and Risk in Highly Urbanized Coastal in Almere generally have at least 1.2 m of offset potential increases runoff due to future Control Storage. Journal of Water Resources Watersheds. Rice University. available storage (Visser, 2017), which means development. However, more work should be Planning and Management, 136(5), 597–601. Singh, R. B., & Singh, S. (2011). Rapid that increases in volume can generally be done to thoroughly investigate the feasibility doi:10.1061/(ASCE)WR.1943-5452.0000066 urbanization and induced flood risk in Noida, accommodated. of incorporating retention and determine the Fisher, R. (1989). Urban policy in Houston, India, Asian Geographer, Vol 28, Issue 2, 147- optimal level of on-site mitigation needed. Texas. Urban Studies, 26, 144-154. 169. In the Cypress Creek watershed, runoff This analysis has only considered a single Halleux, J.-M., Marcinczak, S., & van der Spaan, K. (2017 June 7). Personal Interview. volume increases remain relatively constant design storm, however it is important to Krabben, E. (2012). The adaptive efficiency of Suriya, S., & Mudgal, B. V. (2012). Impact of across all three locations (Table 6). This investigate land use impacts under a range of land use planning measured by the control of urbanization on flooding: The Thirusoolam is likely because the average increase in storm conditions, including actual historical urban sprawl. The cases of the Netherlands, sub watershed - A case study. Journal of imperviousness remains relatively constant storm events, to get a better understanding Belgium and Poland. Land Use Policy, Hydrology, 412-413, 210–219. doi:10.1016/j. across the drainage area. In the upper of the effectiveness of different mitigation 29(4), 887–898. doi:https://doi.org/10.1016/j. jhydrol.2011.05.008 portion, undeveloped land is converted to low strategies. Finally, future work should aim landusepol.2012.01.008 Torres, J. M., Bass, B., Irza, N., Fang, Z., Proft, intensity residential, while in the downstream to link increases in peak flow to increases in Juan, A., Hughes, C., Fang, Z., & Bedient, J., Dawson, C., Kiani, M., & Bedient, P. (2015). portion residential land is converted to high inundation extent. In some cases, drainage P. B. (2017). Hydrologic Performance of Characterizing the hydraulic interactions of intensity commercial. channels may have adequate capacity to Watershed-scale Low-Impact Development hurricane storm surge and rainfall-runoff handle excess runoff, but in other cases in a High-intensity Rainfall Region. Journal of for the Houston-Galveston region. Coastal In Almere, the future development scenario increases in peak flow could substantially irrigation and Drainage Engineering, 143(4). Engineering, Elsevier B. V., 106, 7-19. that incorporates on-site retention is shown increase inundated areas. Kalyanapu, A. J., Burian, S. J., & McPherson, T. Vieux, B. E. & Bedient, P. B. (2004). Assessing to effectively mitigate increases in peak flow N. (2009). Effect of land use-based surface urban hydrologic preduction accuracy and runoff volume. Figure 4 demonstrates References roughness on hydrologic model output. through event reconstruction. Journal of that at almost all watch point locations, the Alig, R. J., Kline, J. D., & Lichtenstein, M. Journal of Spatial Hydrology, 9(2), 51–71. Hydrology, 299, 217-236. incorporation of onsite detention returns (2004). Urbanization on the US landscape: Retrieved from http://spatialhydrology.net/ Vieux, B. E., and Vieux, J. E. (2002). VfloTM: the runoff hydrograph to its natural state. In Looking ahead in the 21st century. Landscape index.php/JOSH/article/view/84 A Real-time Distributed Hydrologic Model. fact, table 4 shows at one location on-site and Urban Planning, 69(2-3), 219–234. https:// Khan, S. D. (2005). Urban development and Normam, OK. retention could decrease the peak flow below doi.org/10.1016/j.landurbplan.2003.07.004 flooding in Houston Texas, inferences from Visser, M. (2017 June 13). Personal Interview. existing conditions. Additionally, on-site Balkema, J. (2017, June 7). Personal Interview. remote sensing data using neural network Qian, Z. (2010). Without zoning: Urban retention reduces the overall runoff volume Bhaduri, B., Harbor, J., Engel, B. et al. technique, Environmental Geology, Vol 47, development and land use controls in to existing conditions at all locations except Environmental Management (2000) 26: 643. Issue 8, 1120-1127. Houston. Cities, 27(1), 31–41. doi:https://doi. one. The exception at location 1, where on- https://doi.org/10.1007/s002670010122 Leopold, L. (1968). Hydrology for Urban Land org/10.1016/j.cities.2009.11.006 site retention is unable to mitigate impacts, Brody, S., Blessing, R., Sebastian, A., & Planning - A Guidebook on the Hydrologic Zhou, Z., Qu, L., & Zou, T. (2015). Quantitative is likely due to the type of development Bedient, P. (2014). Examining the impact of Effects of Urban Land Use. Geological Survey analysis of urban pluvial llood alleviation by occurring upstream. This area is projected land use / land cover characteristics on flood Circular, 554, 1–21. Retrieved from http:// open surface water systems in New Towns: to experience high-intensity development in losses. Journal of Environmental Planning and enviro.lclark.edu/resources/Tryon/Water/ Comparing almere and Tianjin Eco-City. the future, which cannot be fully mitigated Management, 57(8), 1252–1265. Hydrology.pdf Sustainability (Switzerland), 7(10), 13378– by a retention requirement of only 20 City of Houston (2013). Design Manual, Olivera, F., & Defee, B. B. (2007). 13398. doi:10.3390/su71013378 mm/hr. However, this analysis has shown Chapter 9: Stormwater Design Requirements. URBANIZATION AND ITS EFFECT ON that retention is a viable option for flood Crossett, K. M., Culliton, T. J., Wiley, P. C., & RUNOFF IN THE WHITEOAK BAYOU risk mitigation under future development Goodspeed, T. R. (2004). Population Trends WATERSHED , TEXAS. Journal of the conditions. along the Coastal United States: 1980-2008. American Water Resources Association, 43(1), 132 Washington, D.C.: NOAA. 170–182. 133 Almere birds eye Sarah Reinert view from the south. (photo courtesy Almere municipality FLOOD RISK COMMUNICATION PLANS OF ALMERE AND IJBURG and Bart Stoffels).

COMPONENTS FOR COMMUNICATION TO INCREASE PUBLIC AWARENESS OF FLOODS

Sarah Reinert is an undergraduate student at applied to the Houston and Galveston region. from the Houston and Galveston region and Texas A&M University, Galveston with a major These questions are both relevant and the Netherlands. The interviews were coded in Communication and a minor in Business. critically important steps to reducing further and put into categories deemed to be most Her research focus is on risk communication injuries, fatalities, and economic damages. relevant to the research questions. These The Netherlands, being notorious for their categories were then broken down and protection from the water, was the ideal place simplified into components that were used A significant problem needing to be to conduct a comparative study. Almere and to make up a communication plan for flood addressed within flood risk is public IJburg provide similarities to the conditions in risk awareness. Interviews were chosen to awareness. The incoming data that scientific the Houston and Galveston region including get a wide range of answers and discover the researchers are continuing to discover their vulnerability to both inland flooding commonalities within the responses. on hurricanes and flood risk are being from rainfall and storm surge flooding. improperly communicated or simply not The results of this research found that to get communicated at all to the general public. These questions sparked my interest after the message from the expert to the audience With Texas’ sprawl continuing to increase, living in New Orleans, Florida and Texas three components must be considered: the Houston has moved to become the fourth and constantly being exposed to the audience type, the environment in which the largest city in the U.S. (Hively, T, 2016.) The devastating effects that flooding can have message is being delivered, and the delivery population of Houston continues to increase on communities. Over the years the phrase method that is being used to communicate as economic opportunity continues to ‘we did not think it was going to be this bad’ the message. Specifically for a flood risk flourish. Unfortunately, the Houston land is continued to ring through my ears. WHY do communication plan, the audience should be not meant to accommodate for this many people not think that the threats of flooding prone to flood risk, the environment should people. According to Dr. Sam Brody, the are that bad? WHAT causes them to be so be engaging and two-sided, and the delivery leading force driving and exacerbating flood unaware? Through Hurricane Ike, Katrina, and method should include media with graphics, losses over time is human development now Harvey, the pattern for costly hurricanes dramatic wording, and specifics. (Lester, H., & Gabe, G, 2017). It is the hitting the coast is not something that should continuous pouring of concrete over the be taken lightly. Flood damage is inevitable. Materials and Methods bayous and wetlands that is diverting the Being aware of your risk is not. In order to The research began by developing an water into homes instead of its natural lessen the flooding impacts on people’s interview guide which was asked to 8 experts, pathway. People are coming to Houston for homes, jobs, and families it is time that four from the Houston and Galveston region economic opportunity, but remain unaware someone takes responsibility to make people and four from the Netherlands. The interview of the potential economic and personal aware. was semi-structured. It contained twelve devastation that could come from living in questions, five introductory and seven flood the vulnerable area of flood risk. The objective of this study was to better risk related questions. The questions were understand the communication barriers used simply to begin a conversation, and This study concentrates on how to that prevent the general public from being other thoughts or information that drifted develop a communication plan suited to aware of their flood risk. After understanding from those questions were welcome. At the increase general public awareness of flood why, my objective shifted to develop end of the interview, each expert was given risk. Specifically, the research sought to a communication plan that contained the opportunity to provide any additional address what components of a flood risk components designed to increase awareness. information that they believed to be relevant communication plan can increase public This research helps fill the gaps between to this study. Data was also collected from awareness of flood risk within a community. research of flood risk and risk communication. lectures, conversations with other flood Using a comparative study of two dual threat Better knowledge of how to communicate experts, and case study field trips. Once all flooding communities with communication these risks will come from this research. of the interviews were conducted and data plans, I also sought to answer if the was gathered, the information was coded to comparative study results of the Almere This quantitative research was conducted find common themes. There were seventeen 134 and IJburg communication plans can be through interviews with flood risk experts narrow themes found within the coding. 135 Figure 1. After coding the interviews, the other data Jikke Balkema (personal communication, The environment which the message is being was organized to find themes as well. First, June 2, 2017) explained in her interview delivered must be active and engaging. In the communication plans of Almere and that audience type can be divided into 4 order to intrigue those lacking interest, one IJburg were written out in detail. Once main categories. The top 25% include those must adjust the atmosphere away from the both were written in similar structure, who care about their flood risk or the flood scientific structure. An interview participant a comparative analysis was conducted. risk of others. These people want a plan gave an example of a creative atmosphere Similarly, the differences were recorded and and a solution. They are very proactive and that used in Almere was a boat tour analyzed to see which of the two would be engaged. Some of these people include throughout the town. There were eight times more effective for a flood risk communication researchers, stakeholders, and those with a the amount of people that typically attended. plan. After all had been coded and organized, traumatic flood experience. The next 25% Those who came for the free boat ride left the smaller themes found were merged are those concerned with flood risk, but do with a better knowledge of the water risk in into three broad themes. These final not have it as a priority. They are considered the town. components were used to develop a flood moderately interested in flood risk. These risk communication plan (Figure 2). type of people include many government The delivery method was found to be officials and those with moderate flood one of the most crucial components to Results experiences. Next, the 25% who believe that developing a flood risk communication The coded interviews surfaced seventeen flood risk is a problem but because they plan. With technology continuing to rise, a minor themes (Figure 1). These themes are not at risk, it is not their problem. These traditional lecture environment is becoming include people are uninvolved with no intention to less and less common. Now with social 1. mitigation risk approaches get involved if they are not at all affected by media outlets such as Facebook, Twitter, 2. assumptions the risk. They include residents near but not and Instagram, a message can be delivered 3. awareness within the flood plain. The last 25% are those and spread to mass amounts of people with 4. culture with a skeptic mentality. They believe that a a click of a button. The experts that were 5. flood risk flood significant enough to put them at risk interviewed have discovered that posting 6. government communication problems will not happen within their lifetime. These their findings on social media has allowed 7. communication on the local are likely residents and some government more open communication and brought 8. national level officials. When delivering a message more awareness to those particularly 9. state level about flood risk, it is important that the affected by flood risk. Dr. Brody (personal 10. negatively communicated research audience remains distributed close to these communication, June 3, 2017).stated in his 11. positively communicated research percentages. If skewed too far to the right, interview that incorporating charts, graphics 12. public it is too difficult to gain the interest of the and maps into the delivery method allows 13. research outlets audience. Another important factor with the easy interpretation of the message. The 14. resilience audience to consider before trying to deliver simplicity of the message is important. While 15. strong public reaction a message is to focus your audience to the scholarly journals and publications are still Figure 2.(left) 16. weak public reaction top two categories of people. Those are the very important and needed, digesting that Research method 17. vulnerability. people who have potential to be persuaded information into a simple and clear message leading to three by the message. While those in the bottom that can be used for media is becoming an communication The other data collected surfaced three 50% have the potential to be persuaded, it equal necessity. components. themes including is most likely that something traumatic will - audience have to occur rather than hearing a message A comparative chart (Figure 4, next page) Figure 3. (right) - message before they will move up on the spectrum. In was made for the Almere and IJburg plans Three communication - solution. a different interview, Dr. Newman (personal as well. It includes both the similarities and components that communication, June 3, 2017) noted that the differenced between the two plans. The chart must be considered From these subthemes, larger themes public’s distrust can increase very easily. It is shows these similarities and differences. to get the message have emerged. To get the message from important to gain that trust before pushing This data was used to analyze effective from the expert to the expert to the audience, there are three your message too hard. If one decides to talk communication plan strategies already in the audience. communication components that must be to the bottom 50% of people, the likelihood place in similar locations. considered (Figure 3).. These include that they distrust is much higher. The top - the audience type 50% comes with a slightly more open mind to Discussion - the environment in which the message is hear the message. This is not to say that the Many have studied flood risk and being delivered message should not be given to the bottom communicating risk, but few have combined - the delivery method that is being used to 50%. It simply means that when constructing the two together. Prior to the study, I communicate the message. a message, the target audience should be hypothesized that the media outlet would be 136 those in the top 50%. an important component to increasing flood 137 Figure 4. risk awareness. I also considered the use of this research has opened door for a very References Comparative chart charts and graphics would play an important relevant problem that needs to have a Hively, T. (2016). Houston. of Almere and role. One thing that I did not assume in my solution discovered quickly. Lester, H., & Gabe, G. A Look at Why Houston IJburg flood risk hypothesis was that the atmosphere that Floods. (2017). (Accession Number: communication one surrounds his/her audience in will be a In conclusion, the research conducted edsnhe.NBCH112802; Publication Type: plans to the public. component to how they receive the message. from the Netherlands NSF PIRE trip Video; Source: NBC Nightly News; Language: The results of this study highlighted the consisted of three main sources of data. English; Publication Date: 20170827; Physical experts’ opinions on flood risk as well as The interviews with experts provided Description: 1 streaming video file (2 min., what they believe should be the message experience, perspective and commonalities 10 sec.); Imprint: New York : NBCUniversal communicated to the general public. The that could be linked to develop a flood risk Media, LLC., 2017). NBC Nightly News. components for the message emerged from reduction message. The casual talks with the lectures, discussions with the Dutch and Dutch colleagues along with the lectures partnering colleges, and interactive activities and field trips provided components such that took place in the Netherlands. as environment and audience type that had not been originally hypothesized to It is important to note the differences within effect a communication plan. Lastly, the the Almere and Ijburg plans provided to communication plans of Almere and Ijburg be much more insightful than originally (two cities coping with flood risk) provided predicted. While both had plans, IJburg’s a comparative analysis that allowed me to was much more organized and uniform. It find both strengths and flaws within each was easy to understand their message to plan. I determined through analysis of these build a rainproof town. They incorporated plans and data that a flood risk reduction interactive activities, community involvement, communication campaign used in the informational websites and procures, Houston and Galveston region would be most and aesthetically pleasing graphics and effective including three components: the charts. Overall, the comparison between audience type, the environment in which the Almere and IJburg led me to conclude that message is being delivered, and the delivery a communication plan for the Houston method that is being used to communicate and Galveston region would bring more the message. By also comparing the two awareness of flood risk if following the Ijburg case studies, I conclude the the Houston and plan. That is not to disregard the Almere plan Galveston region would have an effective entirely. The similarities with in their plans plan if we reproduce a similar plan to IJburg’s strengthened my opinion on the inclusiveness communication plan. of the strategies within the Houston and Galveston region.

Possible bias within this study could be the lack of interviews with the general public. I was able to interview experts and receive their opinion on the most important things that need to be expressed about flood risk, but I did not get the opinion of the general public. This may skew the results when putting the communication plan into effect. Ultimately, this study gathered critically important data to set the foundation of the components needed to build a communication plan for flood risk awareness. In the future, more research could be conducted within this topic, but specifically a quantitative study needs to be conducted to see how if the communication plan components increase general public 138 awareness of their flood risk. I believe that 139 Figure 1. Work Ki Jin Seong Process (May 31 – August 30) PHYSICAL AND SOCIAL VULNERABILITY OF SOCIAL HOUSING AND PERIODIC MAINTENANCE OF HOUSING ASSOCIATIONS

ALMERE, THE NETHERLANDS

Ki Jin Seong is a Ph.D. Candidate, Department Social housing in the Netherlands is and list up building components for of Landscape Architecture and Urban Plan- subsidized rental housing for which the periodic maintenance for flood protection ning Texas A&M University, College Station, TX initial monthly rent is under the rent limit and long-term resilience; and finally, (3) to for liberalized tenancy agreements for create an organized composite information private sector of €710.68 (in 2016)3. Based template for each social housing unit so that on the Government of the Netherlands, housing associations better aware physical about 75% of the 3 million rental housing vulnerability of each unit and prepare for the Urban development in Amsterdam has in the Netherlands are owned by housing future plan of upcoming maintenance. changed for the past decades from large associations which provide homes for people scale development projects to small-scale in needs4. As landlords, housing associations Interviews with professionals and field and gradual interventions. Almere was one have responsibilities of major repairs and visits were mainly conducted during the of the focusing areas that were planned maintenances of homes. Specifically, the Netherlands trip in early June. Then, GIS for economic vitality and sustainable important role of housing associations in mapping and spatial analysis were done to development in mid-60’s (Kahn & van der periodic maintenance is to assign annual identify physical and social characteristics of Plas, 1999). Reclaimed from the Ijsselmeer, budget of maintenance for homes and the the residential neighborhoods. In addition, Almere has the largest population of the immediate surroundings and to encourage STATA were used for statistical analysis Figure 2. municipalities in the province of Flevoland cooperation between the municipalities and to check the correlation between the Methodology. in 2017 with 201,703 of citizens1. In the public for better quality of life. In short, percentage of social housing and physical/ addition, the city has a plan to expand its housing associations have a pivotal role social characteristics at neighborhood population to 350,000 by 20302 and will in connecting publicity and the everyday level. Central Bureauvor de Statistiek (CBS) attempt experimental approaches to urban individual maintenance. Total amount of open data, AHN (Digital Elevation Map developments, housing, and regional plans in social housing owned by housing association of the Netherlands), Trimble dataset for this process. in Almere is 21,035 (Almere, 2013b). Most infrastructures, Waterschap Zuiderzeeland of association houses are run by major data for hydrological infrastructures and Although Almere is a relatively young town corporations including De Alliantie, Ymere, Social Atlas Almere 2013 were collected for compared to other historic Dutch cities, Goedestede, Woonzorg Netherland, Habion the spatial and statistical analysis. such as Amsterdam, Delft, or Utrecht, aging and Eigen Haard. of building and infrastructures is inevitable This research contributes to better concern in this city as well. Structures The primary research question of this study understand the current environmental have been weakened by deterioration, is: condition of social housing that might affect exacerbating vulnerability to disasters What is physical and social vulnerability of deterioration of residential buildings. And (Maskrey, 1989; Taboroff, 2000; Teferra, 2013). social housing units in Almere? And how it also encourages housing association to In addition, damages are aggravated through can building components of social housing actively engage into the process of structural the lack of maintenance (Maskrey, 1989). be itemized for periodic maintenance and non-structural hazard mitigation by What is worse, poorly maintained housings for flood protection and how do housing better performing periodic maintenance. and infrastructures may consistently influence associations support the maintenance s Furthermore, this study can enhance the on health of residents, increasing rates of ystem? municipality to improve the resilience mortality in emergency (flooding, extreme To be specific, the purpose of this research of housing and thereby improving a heat, etc.) and morbidity with infectious and is (1) to identify physical and social community’s resilience. chronic disease after the events (Krieger & vulnerability by neighborhood level and Higgins, 2002; Sanders, 2007). Therefore, where social housing units operated by Data collection periodic maintenance and strategic retrofit housing associations are located in each The collected data (Figure 1) were mainly plans should be established in a long-term neighborhood; (2) to investigate the used for GIS mapping and spatial analysis. 140 view. maintenance system of housing association Then, correlation between the variables 141 Figure 4. (Right Top) (Left Bottom) (Right Bottom) were checked. Central Bureau voor de In the meantime, the role of housing This results shows that the location and (Left Top) DEM Sum of Social Percent of Low Percent of Statistiek (CBS) open data were collected association in the maintenance system were density of social housing are related to (Elevation) map of Housing by Buurt Income Households Non-Western for geographic boundaries including buurt investigated and the building components physical and social characteristics of the Almere, (Neighborhood). by Buurt Households by Buurt (neighborhood), wijk (district), and gemeente for flood protection were listed up through neighborhood. Based on the result, the (municipality). AHN2 DEM dataset were secondary content analysis from step 1. Third, physical characteristics of a neighborhood collected as 5m grid resolution raster images neighborhood characteristics and itemized is expanded to three indicators: distance to to identify elevation. GIS dataset for basic building components were combined to water; average elevation around 100m buffer infrastructures were collected through inform housing association to design a of the social housing building; and age of the Trimble open data. Specific GIS data for systematic maintenance of each social social housing building. In terms of the social hydrological infrastructures (including housing unit. Finally, implication for flood characteristics, 8 indicators were investigated Duikers, Gemalen, InlaatAflaatHevels, Stuwen, protection of multifamily housing in Harris as shown in Table 2. The result indicates Syphons, and Watergangen) were collected County were derived. correlations between the percent of social through Waterschap Zuiderzeeland. In housing and physical/social vulnerability addition, the Social Atlas Almere 2013 and Social Housing in Almere, the Netherlands indicators. Findings show that social housing Amsterdam Federation Housing Association Almere is part of the province of Flevoland has a strong positive relationship with rental (AFWC) 2017 dataset provided socio- and located in the middle of the Netherlands. cost, particularly in a lower rental range demographic characteristics of social housing Because the City was reclaimed from Lake under 375 euro. In addition, low-income level in each neighborhood. Ijssel and is surrounded by interconnected has a strong positive relationship with social lakes, most areas in Almere are very close housing. Work process to the water and below sea level that is very Primary interviews with City officials in vulnerable to floodings, especially in case Appendix 1 shows the result in detail. Social Almere, Water Authority, and Waternet of a dike failure (Almere, 2013a). Almere has housing basically has moderate relationships Amsterdam were conducted as team expanded a city with a population growth in rental ranges except the 375-536 euro meetings during the Netherlands trip of approximately 201,700. As seen in Figure rental level. The higher the percent of social (May 31 – June 15). Additionally, individual 3, the existing districts include Almere- housing is, the higher rental homes under interviews with Dr. Fred C. Sanders and Dr. Stad, the main city centre, Almere-Haven, 375 euro for rental cost are. On the other Maarten Van Ham at TU Delft were added to Almere-Buiten (outside), Almere- Poort and hands, the percent of social housing has identify the overall history of social housing Almere-Hout. The major parts of the city are a negative relationship with rental range in the Netherlands and the role of housing demarcated by lakes and extensive wetland more than 536 euro. In addition, areas with association in periodic maintenance. Dataset area called “Oostvaarderplassen.” higher percentage of private homes have for hydrological infrastructures, reports and lower percent of social housing. Moreover, related websites were also collected during Physical and Social Characteristics by the percentage of low-income household the trip, and additional dataset including Neighborhood in an area has a strong relationship with Social Atlas 2013, AFWC, and Trimble data, 36 out of 66 buurts (neighborhood) in housing type, showing a strong negative were used for the analysis in the makeup Almere are residential neighborhood based association with percentage of private homes research period. GIS mapping, Statistical on land use planning. Figure 4 shows (-0.8981), while a strong positive relationship Analysis, and sample application were characteristics of residential neighborhood with social housing percentage (0.9023) designed in July and August. in Almere. First, based on the DEM map, with both 0.000 significant level. And the almost all neighborhoods are below sea level. percentage low-income household has a Methodology Especially, eastern parts including Almere- moderate relationship with the percentage of As shown in Figure 2, this study was buiten and Almere-Hout are the lowest non-western household (0.4157 with a 0.000 conducted through 4 steps. First of all, areas. Second map shows the sum of social significant level). physical and social characteristics were housing at buurt level. It shows that social mapped by neighborhood level using housing units are highly concentrated on Housing Associationx in the Netherlands collected GIS dataset. And information from Almere-Stad and Almere-Haven, where the The history of social housing in the in-depth interviews, field research, literature percent of low income households are higher Netherlands started from the 1901 review, and governmental reports regarding as well. In Almere-Haven, for example, social Housing act, which set up the duties and social housing and housing associations housing is extremely concentrated on De responsibilities of housing associations. were combined. Second, data from step Wierden buurt with 177 units. Approximately Performing duties for the social rented 1 were used to investigate the correlation 60.25% of households are low-income level sector management, housing associations between the percent of social housing in this area (Figure 4, Left bottom) and more has gradually exempted from corporation and other physical/social characteristics than 29.25% of households are non-western tax that eventually enabled to reduce of each neighborhood. In this process, (Figure 4, Right bottom). prices for building social housing (Elsinga 142 STATA was used for the statistical analysis. & Wassenberg, 2007). Continuing 143 Figure 5. deregulation of the social rental sector has Systematic Maintenance Design for Social be generalized in any urban development The Role of Housing resulted in the financial independence of Housing areas. Multifamily housing in Harris County Associations. housing association. In mid-90’s, the Dutch Based on the mapping of GIS data, the in Texas is one of the examples that has Source: Wolf Property government allowed non-profit associations identification of physical and social similar concerns of dilapidation and deferred Management Platform. to liberalize rents to create profits for some characteristics of neighborhoods and the maintenance of multifamily housing of rental housing. Since 2001, the government list-up building elements of social housing, buildings. This study will specifically look at has treated non-profit and for-profit this chapter focused on combining and Greenspoint neighborhood in Harris County landlords differently, limiting the rent increase applying overall information. Finally, a where has been developed since mid-70’s. at a different rate and regulating non-profit composite maintenance guideline for each organizations not to pursue profit-making. social housing unit were designed. Figure Greenspoint neighborhood is located in This is because deregulation of the social 6 shows the example of a specific social northern part of Houston near George rental sector has aggravated the quality housing unit located in Almere-Haven district. Bush International Airport. Since 1980’s, the of existing social housing, deferring The property “Overhead 6” is a masonry neighborhood has been filled with apartment periodic maintenance. It is called “Decree apartment built in 1981. The composition complexes and now, it has one of the largest on management of social rent sector (The of a unit basically includes 2 bedrooms, 1 concentrations of multi-family housing in Besluit Beheer Sociale Huursector, BBSH) bathroom, living room, kitchen, and terrace. Houston with 11,000 apartments (85% of Table 1. and so far it has been a significant role in The average elevation of the unit is 2.34m all housing in the neighborhood) (Rogers, Data Collection. practice by forcing housing associations to below sea level and is 21.4 meters away from 2016). In addition, more than one thirds perform six key tasks; the prioritization of the closest waterway. Right below of the residents live below the federal poverty line appropriate accommodation for the target Figure shows the expected maintenance year and 24% of households do not own a car. group, the qualitative upkeep of the housing calculated. Assuming the property has been What is worse, about 3,500 out of 6,321 stock in maintenance, renovation, and new regularly managed replacement, retrofit and rental units are in the floodway as shown construction of social rental dwellings; the changing deteriorated building elements, the in Figure 7. Because of repetitive flooding involvement of tenants in the management of maintenance year is estimated based on the events, many of buildings has constantly their dwellings and the development of new age of the building and its life expectancy of damaged by water and wooden structures policy; the guarantee of financial continuity of each component. not properly managed during disasters the housing association; a contribution to the has been rapidly dilapidated. Therefore, quality of life in the neighborhood; and the This guideline enables both a housing identifying and assessing physical and combination of housing and care (Ouwehand association and tenants to better understand social vulnerability of the neighborhood & Van Daalen, 2002). the current condition of built environment, and providing maintenance guideline of including physical vulnerability of the building components would be helpful to Maintenance of Building Elements neighborhood where the dwelling is situated aware existing hazards and prioritize building Overall, it is clear that housing associations are and aging condition of the social housing maintenance based on cost-effectiveness and the main player in the maintenance system unit. By doing so, the housing association life expectancy. of social housing. They maintain homes may use this information in the decision- preventively and periodically, expecting to making process to determine the priority Conclusion expand the life span of the property and keep of maintenance for upcoming years. At The Netherlands is the country with the the quality of housing. For example, according the same time, it might be a useful tool for largest share of social housing in the EU, Table 2.. to the annual report of De Alliantie 2016, which tenants to decide where to move based taking up about 32% of the total housing Correlations between is the biggest housing association for social on neighborhood characteristics and the stock (Europe, 2010). Despite of the large physicla and housing in Almere6, about € 155 million was maintenance condition of the unit. In addition, amounts of dwellings, its value in the social vulnerability consumed for maintenance and improvement, sharing the transparent maintenance discourse on flood protection tends to be indicators and the which is 42% of the total expenditure per process may encourage tenants to monitor underestimated. The main research question percent of social year (Alliantie, 2016). Therefore, an effective, the maintenance system and to be actively of this study is first, to identify physical and housing systematic maintenance is important to involved in the minor level maintenance in social vulnerability of social housing units in housing associations in practice. Through everyday life. It will create a virtuous and the young city, Almere, second, to investigate literature review and secondary content healthy cycle of maintenance system that the maintenance system of housing analysis, this study organized the rental diverse stakeholders engaging into the association, and third, to design a composite housing elements list for the periodic process in practice. maintenance guideline for social housing maintenance (Table 3). It is categorized by for long-term flood protection as well as building structure, building envelope and Application to Multifamily Housing in Harris community resilience. As methodologies, semi-public space. And relative maintenance County, Texas in-depth interview, content analysis, GIS costs and life expectancy were identified. Aging of buildings and infrastructures is mapping and statistical analysis were 144 not a unique problem of Almere; it may conducted. 145

Figure 6. Relative Life Table 3. Category Elements Home Components Description Maintenance Expectancy Example: The Costs (Years) Rental Building Maintenance Building Foundation Wood pile decay, termite infestation, severe splits, connection to framing ●● 2-20 Elements for Periodic Guideline for Social Structure Sill plates deterioration, splits, lack of attachment to foundation ●● 2-20 Maintenance Masonry deteriorated mortar joints, cracked block, step cracks indicating foundation ●●● 2-100 Housing “Overhead 6”. settlement Concrete spalling, exposed or corroding reinforcing steel, ≥ 1/4-inch vertical cracks or ●●● 2-27 Source: FEMA. horizontal cracks with lateral shift in the concrete across the crack (2011). Coastal

Porches/ Columns Top and bottom corrosion in connectors ●●● 5 Construction Manual: connections to framing Principles and Base of wood columns deterioration ●●● 50 Practices of Planning, Floors Joists or beams decay, termite infestation, corrosion at tiedown connectors, splits, excessive holes or ●●● 50 notching, excessive sagging Siting, Designing, Sheathing deterioration, “squeaky” floors, excessive sagging, attachment to framing (nails ●● 25 Constructing, and missing, withdrawn, or not attached to framing) Maintaining Sheathing under floors attachment to framing, nail corrosion fastening sheathing to floor joists, ● 10 buckling/warping caused by excessive moisture Residential Buildings Attic Framing condition of truss plates sagging or bowed rafters or truss chords, deterioration of ●● 30 in Coastal Areas./ underside of roof sheathing, evidence of water leaks, adequate ventilation Schoeman, L. (2015). Building Exterior Walls Siding deterioration, nail withdrawal, discoloration, buckling, attachment to studs (nails ●● 20 Ready to Respond: Envelope missing, withdrawn, or not attached to studs), sealant cracked/dried out Trim deterioration, discoloration, separation at joints, sealant cracked/ dried out ●● 25 Strategies for Green façade hold rainwater and evaporate later; substration attachement to the façade neends ● 10 Multifamily Building more maintenance, waterin gand fertilization Resilience. Windows/ Glazing cracked panes, condensation between panes of insulated glass, nicks in glass surface, ●● 17.5 Doors sealant cracked/dried out Trim deterioration, discoloration, separation at joints, caulking dried out or separated ● 25 Shutters permanent shutters should be operated at least twice/year and temporary panels ● 17.5 should be checked once/year for condition Lockable buildings similar to baffles or shutters to let water kept out of doors; small openings, open ● 2 joints, ventilation gratings, cloacks, letterboxes are also applicable Roof Asphalt shingles granule loss, shingles curled, nails withdrawing from sheathing, ●●● 20 de-bonding of tabs along eaves and corners Wood shakes splits, discoloration, deterioration, moss growth, attachment ●●● 30 to framing (nails missing, withdrawn, or not attached to framing) Metal corrosion, discoloration, connection of fasteners or fastening system adequacy ●●● 3-7 Flashings corrosion, joints separated, nails withdrawing ●● 2 Semi-public Street-Building Floor level stairs to salt trains, basement ramps and other lower buildings included, Thresholds ●● 1 Space Boundary at outside doors and slightly elevated ground floor for protection against moderate water pollution Pump with non-return backflow of waste water or rainwater from the sewer ● 3 valve Temporary water cures temporary waterings with the form of movable elements with water or sand for ●● 1 emergency situation Rainproof Utilities The above level the above-ground level utilities for transformer cabinets and network cabinets ●● 10 cabinets Landscapes and Rainwater ponds small retention ponds at front yards; relatively little space needed but maintenance ●● 2 Gardens is necessary due to the purification system Greens between tiles impervious cover with lots of tiles causes runoff; planted soil instead of tiles; labor ●● 0.5 intensive in maintenance Infiltration Strips with infiltration strips with deepened fields; connected to paved surface; maintenance in ●● 1 topsoil storage soil quality (in terms of permeabilty of the soil) and infiltration capacity should be managed. Infiltration Fields flat-shape infiltration; underground infiltration facililties are more efficient with ● 0.3 regard to space use, but require regular maintenance. Planting native, indigenous plants needed. Deep soilbed is required for higher planting; lawn ● 0.1 also contributes preventing desiccation Disconnect Rain Pipe Dismantling rain pipes at buildings from the sewage drains the sewage system; ● 0.5 temorarily hold rainwater and slowly infiltrate Infiltratration Wells underground soil infiltration facilities; vertical rainwater drainage; requires relatively ●●● 0.5 little space but regular cleaning and maintenance are necessary Pavement Hard half-hardening Grind, stone and shells -- for semi-hardening to; water sink into the soil and ●● 2 supplement the groundwater; periodic filling is necessary due to sagging. Gentle half-hardening natural products such as wood chips, pine buns, and cocoa heads are water-& air- ● 1 permeable; those products are not taxable and not suitable for cycling or transport Water-borne hardening open joints vowels for lowering the rainwater in the ground; porous vowels can slug ● 1 close and require extra management and maintenance Grass Pebbles can be applied to less intensively used parking spaces, roads, garage buildings and ● 1 146 gardens; low load capacity and can be easily broken by heavy vehicles 147 Table 3. Rental Building Elements for Periodic Maintenance Figure 7. In conclusion, this research contributes to Amsterdam. Cities, 16(5), 371-381. 2, 71-79. Multi-familiy Housing better understand the current environmental Krieger, J., & Higgins, D. L. (2002). Housing Teferra, A. (2013). 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Alaina Parker is a senior pursuing her bach- and size of storm surge the Gulf Coast will hamper the environments ability to cope com/hazard..htm. elors at Landscape Architecture from Texas experience. A six foot increase in sea level with storm water during inundation events; Copyright HGAC. A&M University alongside a minor of Urban & by the year 2100, especially in areas already as urban growth corresponds to an increase Regional Planning. at risk of subsidence, will increase “risk of in impervious surfaces such as roadway flooding in cities, inhabited islands, and tidal infrastructure, development, sidewalks, etc. Abstract wetlands” (“Climate change impacts”, n.d.). Increased impervious surface coverage aids Located in the Gulf of Mexico with some of Hurricane Ike alone cost the United States in increasing storm water runoff and peak the fastest growing areas within the United $29 billion in damages, in addition to losses discharges, higher occurrences of stream States, the Houston-Galveston Metropolitan of infrastructure, food services, retail and peak flows, increased channel erosion due Area is in a precarious position as flood manufacturing, displacement of workers, to alterations in the transport of water and risk threatens to cripple local economies consumer and tourists (“The storm resource”, sediments, etc. (O’Driscoll et al., 2010). The alongside the health, safety, and welfare of n.d.). Based on Disaster Impact Modeling the present flood control mechanisms employed, Figure 2. citizens. Climate change alongside increased total post-storm damages were estimated such as detention ponds designed for a 100 The Netherlands urbanization is anticipated to exacerbate to be $142 billion. (“The storm resource”, year storm, become unable to cope with multi-layered safety damages faced in the area; current standards n.d.).The need for the greater Houston- the significantly increased peak flow and approach. Adapted for flood control are inadequate to protect a Galveston Metropolitan area to utilize flood discharge rate of storm water; ultimately from “Flood risk and growing population and to secure sensitive control mechanisms to develop resilient exacerbating risk to surrounding communities. watermanagement economies along the coast. This paper communities is necessary for not only the Approaching future development within the in the Netherlands” serves to explore, define, and understand the health, safety, and welfare of civilians but also Houston-Galveston Metropolitan Area with by Slomp, R. 2012. critical flood risk infrastructure within the to secure local and national economies. the current “flood control” mindset will be And adapted Netherlands new towns of Almere and IJburg. unable to fully eliminate inundation events. from “Concept The analysis of the Almere and IJburg case Misconceptions arise in the United States Consequently, there must be a shift in the Gebiedrapportage study ultimately reveals strategies that can when flood control is used as the primary perception of flood control within the United Eiland van serve as a reference for future development means of protection against inundation States in order to reduce flood risk to local Dordrecht” by Kelder, within the Houston-Galveston Metropolitan events; the solution tends to be a reliance on communities. E., Gersonius, B. & Area. stand-alone structures (such as the levees Hulsebosch, M., 2012. in New Orleans or the Galveston seawall) The Netherlands has been setting worldwide Introduction to “eliminate” the risk of flooding (Williams, precedence in flood risk mitigation and serves Flooding from storm water and hazard events 1994). Upon implementation, maintenance as a model from which the United States has adverse effects on the ecology of human and monitoring of these structures falls by can stand to learn from. Flood and water processes in developed areas; climate change the wayside leaving them inadequate to management serves as the foundation for and the effects of sea level rise will intensify protect during a flood event (Williams, 1994). the Netherlands approach; utilizing “multi- these impacts. The discussion of reducing flood risk to the layered safety” (Figure 2) consisting of: flood greater Houston-Galveston Metropolitan Area protection and defenses, spatial planning The Houston-Galveston Metropolitan area becomes challenging due to its diversity in measures, and flood evacuation (Slomp, 2012). has become increasingly vulnerable to natural size, economy, population, density, etc. As Flood management ultimately aims to reduce disasters as time has progressed, while seen in Figure 1, the majority of the Houston- hazards to the health, safety, and wellbeing climate change additionally exacerbates Galveston population is vulnerable both to the of local communities versus serving as the damages to both human and native risk of inundation in the 100 year floodplain sole solution during a flood event (Williams, environments. Hurricanes are only expected alongside risk of inundation from storm 1994). Structural implementations, such as to become stronger and more frequent as surge during hurricanes and other natural the Maeslant Barrier, and design with nature global frequency will increase from 11% to disasters; risk will only continue to grow with approaches, such as dune revitalization 40% by the year 2100 (Emanuel, 2013). Sea projected population increases into 2030. along the North Sea coastline, have been 150 level rise will also contribute to strength Consequences of increased urbanization integrated into a network of flood risk 151 Figure 3. (left) reduction infrastructure set to protection within Almere and IJburg is significant, structural mechanisms are characterized by Netherlands levels of 1:10,000 year storms (Meyer et al., considering both towns emerged within the their composition of construction materials, regional flood 2009). The Netherlands has invested over $1.3 last 40 years, and each can serve as reference their critical dimensions and relationship to protection. Adapted million per year in risk mitigation, monitoring, for the success of strategic planning in face of urban centers, and their interaction with water from “Dijken van and maintenance; the return value on this increased urbanization and climate change. during normal and storm conditions. Nederland” by F.J. investment has saved the country thousands Pleijster, C van der of lives, dollars, and economic set-backs In response to the growing need for flood risk Methods Veeken, R. Jongerius (Higgins, 2012). Development within the reduction strategies in the Houston-Galveston * Field Research & A.J. Luiten, 2015, Netherlands consists of old and new towns, Metropolitan area, this case study has three The field research conducted within Almere nai010. old towns characterized as developed main objectives: (1) To expose critical flood and IJburg occurred over the span of two between the 17th and 20th century (Meyer risk infrastructure employed in Almere and weeks, May 31- June 16, 2017, and comprised Figure 4. (right) et al., 2009) and new towns characterized IJburg through studying the application of of qualitative data gathering through site Locator Diagram for as thoroughly planned entities funded and the first two layers of the Netherlands “multi- visits that included meetings with municipal Almere and IJburg. driven by municipal authorities to contribute layered safety approach”; (2) to categorize representatives and tours. Each visit began 52011’46.66’’ N to coping with unanticipated urban growth and diagrammatically represent the structural with presentations regarding regional context, and 2044’30.76’’ and arising environmental concerns (Pierre, and non-structural mechanisms that compose city history and evolution, specific approaches E. Google Earth, 1980). To understand how new towns are the flood risk infrastructure in Almere and used towards flood risk management, and December 13, 2015. developing and coping with flood risk in IJburg; (3) to produce a “New Towns Toolkit” how the city will anticipate and respond to Retrieved August 8, the Netherlands, the towns of Almere and detailing construction materials, critical increased inundation risk from climate change. 2017. IJburg will serve as case studies that can dimensions, and interactions with water that Presentations were supported through tours ultimately contribute to enhancing the flood can serve as a flood risk reduction reference that allowed students to experience specific risk reduction strategies employed within the for new and developing communities within critical flood risk infrastructure such as the Greater Houston-Galveston Area. the Houston-Galveston Metropolitan area. intersection of the High and Low Canals at the de Blocq van Kuffeler in Almere, and Almere and IJburg are both located on Definitions the floating houses in IJburg. Both site visits Lake Ijssel, and protected regionally from Before discussion of the Almere and IJburg supported an understanding of the critical the North Sea by the Afsluitdijk and the case study can begin, it is imperative to flood risk infrastructure that acts as the first Houtribdijk as seen in Figure 3; however both define the following terms: critical flood risk line of defense from the North Sea. take on drastically different approaches to infrastructure, structural mechanisms, and development. Considered an extension non-structural mechanisms. * Interview panels with experts of Amsterdam, IJburg (Figure 4) is composed Flood risk in the approach of this case study, Within the two week timespan, interviews of a chain of artificial archipelagos formed is defined as the vulnerability of a population were held with city representatives from Figure 5. from sand reclaimed by the North Sea due to physical environment (Ashley & Ashley, the City of Almere, Water Authority Primary critical flood that is entirely above sea-level. The 2008), while infrastructure is defined as Zuiderzeeland, and Amsterdam Rainproof. risk infrastructure. archipelagos that have been constructed and the framework of a system or organization Expertise of interviewees included: urban Adapted from inhabited include Haveneiland, Steigereiland, (infrastructure, 2017). Thus critical flood risk planning, spatial planning, hydrology, and low “Flood risk and water and Rieteiland. Upon completion, IJburg infrastructure can be characterized as the impact development. Questions asked sought management in the will consist of 10 islands and house around constructed framework within a municipality to define flood infrastructure in both Almere Netherlands” by 45,000 inhabitants (IJburg, n.d.).In contrast, that is primarily responsible for mitigating and IJburg, how infrastructure functions, Slomp, R., 2012. Almere (Figure 4) is located within the flood risk faced to populations in physically its composition, and the capacity to adapt larger Flevoland Polder and is approximately vulnerable areas. The framework can further to future pressures from increased urban 4.5 meters below sea-level. The city of be examined by characterizing individual development and climate change. Lastly, Almere was inspired by Ebenezer Howard’s components that work together to form the inquiries were made to determine where more Garden City movement and is composed system as a whole, for the purposes of this information regarding flood management individual districts joined by infrastructure, paper these are the structural and non- strategies could be found to supplement the districts include: Almere Stad, Almere structural mechanisms. information upon returning to the United Buiten, Almere Haven, Almere Poort, Almere States, such as governmental standards for Hout (currently developing), Almere Pampus Structural mechanisms being those dike construction, materials, etc. (proposed) (“The City of Almere: Districts”, characterized as structural barriers that aid Most importantly, the interviews led to the n.d.). Considered one of the fastest growing in reducing flood risk in combination with ability to categorize flood risk infrastructure cities in Europe, Almere hosts a population of non- structural mechanisms which for the of Almere and IJburg into three tiers of 195,000 and is projected to become the fifth purposes of this paper, are characterized as inundation risk in the form of: dike failure, largest city in Europe (“The City of Almere: implementations that reflect the “design with inland inundation from waterways, and 152 Districts”, n.d.). The urban growth experienced nature approach”. Both structural and non- inundation from extreme rainfall events. 153 Figure 6. The categorization allowed the toolkit to be the possibility of Afsluitdijk and Houtribdijk Visser, personal communication, June 13, Projected rainfall organized from primary lines of flood defense failure. The mechanisms employed by the 2017). inundation trends to tertiary, thus revealing the multi-layered two cities varies drastically, due to the nature 2017-2050. Adapteed approach towards flood risk management and of Almere being a traditional polder-system In anticipation for a larger rain event, the from Waterschap spatial planning the Netherlands takes when below sea-level, and IJburg being an elevated waterways will typically pre-pump water Zuiderzeeland, developing new communities. polder above sea-level. As seen in Figure 5 to create additional storage capacity in Wateropgave the primary flood risk infrastructure for both both the waterways and retention ponds, huidige situatie * Synthesis of pertinent information Almere and IJburg line the city-lake edge, at max capacity the entire water network & wateropgave The criteria for selecting literature related the size of the defenses differs drastically within the Flevoland polder can store up to 2050 [Map]. n.t.d. to flood risk infrastructure within Almere due to the cost effectiveness of developing an additional 1.2 meters of water (M. Visser, Almere, Netherlands, and IJburg was defined by the ability for the traditional polder systems versus creating personal communication, June 13, 2017). The Waterschap source to define how the specific structural elevated polders through sand layering (K. relationship that the entire Flevoland polder Zuiderzeeland, 2012. and non-structural mechanisms within the Spaan, personal communication, June 6, (including the city of Almere) maintains flood risk infrastructure function, material 2017). when interacting with water is to keep water composition, critical dimensions, and the within the water network, store water in both capacity for adaptation. Additional literature Thus, the Flevoland polder in which Almere waterways and retention lakes, and ultimately in combination with information gleaned from is located relies on the perimeter lake dike to discharge water into surrounding bodies of interviews allowed the specific structural ring, the Oostvaardersdijk around Almere water outside of the polder. and non-structural mechanisms within both the compartmental Knardijk (Pleijster et al., Almere and IJburg to first be identified based 2015). The Knardijk separates the Eastern While keeping water levels consistent on the 3.2 categorization and subsequently and Southern Flevoland and acts to contain is imperative in Almere and the greater become diagrammatically represented flooding in the Eastern or Southern Flevoland Flevoland polder, risk of inland inundation through the combination of constructions (depending on which side is breached) to in IJburg is minimal with current climate materials, critical dimensions, and interaction protect half of the polder from flooding conditions due to the nature of its elevated with water. should dike failure occur (M. Visser, personal polder development. Traditional polder communication, June 13, 2017). Whereas, development focuses on separating people IJburg serves as an archipelago chain of from the surrounding water, whereas IJburg RESULTS islands, utilizing sand layering to create has chosen to embrace water through artificial islands 2 meters above sea-level, spatially planning development around blue- Figure 7. Primary Critical Flood Risk Infrastructure there also is an adaptive dike surrounding green grids in which people and water can Projected land use Dike failure is the primary focus of the the elevated polder that serves to protect co-exist (Atelier Groenblauw, n.d.). Whereas trends 2012-2040. Zuiderzee Water Authorities in terms of against rising sea-levels and increased threats Almere is focused on keeping, storing, These diagrams protecting the health, safety, and welfare from climate change should lake levels rise and discharging water, IJburg in contrast were created using of its inhabitants, alongside securing local above IJburg grades. The primary critical is focused on infiltrating water through its ArcGIS® software economies. Primary critical flood risk flood risk infrastructure in Almere and IJburg sand-layered base and conveying sheet bij Esri. ArcGIS® and infrastructure is the frontline defense from have reservoir space to expand and become flow into the nearby blue grids. The sand- ArcMAPTM are the inundation from the North Sea, which unlike reinforced in response to climate change and layering method consists of sedimentation of intellectual property risks of inundation from rainfall, has an infinite increased urban development. .6 meters -.8 meters of sand layers until the of Esri and are used supply of water that can cease an entire finish grade reaches 2 meters above sea- herein under license. polder from functioning (K. Spaan, personal Secondary Critical Flood Risk Infrastructure level, thus allowing for surface storm water Copyright © Esri. communication, June 6, 2017). Both Almere Threat of inundation from inland waterways to infiltrate completely through the elevated All rights reserved. and IJburg are regionally protected from the is the secondary focus when designing polder (de Leeuw et al., 2002). As climate For more information severity of the North Sea through the larger and planning new communities due to the change effects sea-level rise and increased about Esri® software, Afsluitdijk and the Houtribdijk (Pleijster et al., sensitivity of water levels during storm events. storm surge, IJburg has implemented floating please visit www.esri. 2015). These dams reduce the shock Almere In traditional polder developments the major houses that allow homeowners to enjoy com. and IJburg receive during storm events; canals, the minor canals, the wadi living with water while being able to adapt to ultimately they are the Zuiderzee’s first line of (rural swales), and the retention lakes are changing water levels whether from storms or defense against sea inundation. kept at consistent levels through means of climate change (Andersson, 2014). pumping excess water out of the polder into Ultimately, traditional polder development Although not regionally significant, both surrounding water bodies. For example, the creates a reliance on individual mechanisms Almere and IJburg also provide primary High Canal of the Flevoland polder typically within the system and reduces flexibility flood risk infrastructure that is critical to pumps to Lake IJsselmeer and has the in terms of spatial planning and urban reduce threat of inundation from Lake ability to switch water flow direction through development. Any future development within 154 IJsselmeer, and to a somewhat larger extent, manipulating active pumping stations (M. the city of Almere will rely on the capacity 155 Primary Secondary

for the primary and secondary critical flood risk infrastructure to function, whereas IJburg has more flexibility to entertain innovative mechanisms and spatial layout due to its elevated nature.

Tertiary Critical Flood Risk Infrastructure Inundation due to extreme rainfall is tertiary for providing critical infrastructure, due to the efficiency in which the primary and secondary flood risk infrastructure functions. There has yet to be inundation due to intense rainfall in Almere and IJburg, howeverthe risk of localized flooding due to rainfall is expected to increase significantly in the Flevoland polder through 2050 as seen in Figure 6. In addition to the capacity of the water system Tertiary 156 to store rainwater runoff, Almere also employs 157 Primary deep retention lakes such as the Weerwater New Towns Toolkit Almere and IJburg are significantly different, and the Noorderplassen, alongside a high The overall mechanisms that compose the all mechanisms function to interact and percentage of land designated as greenspace critical flood risk infrastructure of both influence the way in which water flows within (J. Balkema, personal communication, June 6, Almere and IJburg are presented in the the new town. The primary means in which 2017). Both the lakes and greenspace allow toolkit below. Mechanisms are categorized water is influenced is through: disruption, for additional storage during rain events by: primary, secondary, and tertiary critical adaption, conveyance, infiltration, and storage. and serve to decrease the rate of runoff flood risk infrastructure along the x-axis; the The combination of mechanisms ultimately that would typically occur in areas with y-axis is a structural to non-structural gradient allow the critical flood risk infrastructure to higher impervious to pervious surface ratios. to demonstrate the permeability in which protect physically vulnerable populations and The lakes have become functional assets mechanisms are being employed (Figure 8). reduce risk of damages. although their primary function was to serve as sand infill for the development of Almere Conclusion & Discussion The overall function of critical flood risk (M. Visser, personal communication, June 13, Critical flood risk infrastructure within Almere infrastructure for Almere is to keep water 2017). Although urbanization is anticipated and IJburg is categorized into three levels of within the polder, store water within the to increase in developed areas around flood risk design: primary critical flood risk water network, and ultimately discharge Primary Almere, through strategic spatial planning infrastructure relating to regional dike failure, water through the pumping stations into Almere with gain an additional 12% of green secondary critical flood risk infrastructure surrounding bodies of water. Almere space by 2040 (Figure 7). Within the Almere serving to protect against inland flooding, contrasts to the function of critical flood 2.0 proposal additional compensation for and tertiary flood risk infrastructure to risk infrastructure in IJburg, which acts to increased development and anticipation for combat inundation caused by extreme rainfall. convey water through sheet flow across future risks of climate change would occur The combination of these three categories surfaces and to infiltrate water through the through the reinforcement of dikes to “super serve to demonstrate the flood protection, sandy base of the elevated polder. Specific dikes” alongside water storage within the defenses, and to a certain extent the spatial site contexts alongside early planning and designated Oosterworld rural area (IP Course planning measures of Almere and IJburg, development goals ultimately influenced Acce, 2013). demonstrating the application of the first these major differences between critical two tiers of the Netherlands “multi-layered flood risk infrastructures within the new In contrast, IJburg employs and will employ a safety” approach. 13 total structural and towns. The coinciding information that arose variety of mechanisms to accommodate for non- structural mechanisms were identified from interviewing experts within both IJburg extreme rain events through the application within Almere (8) and IJburg’s (5) critical and Almere exemplifies that when planning of low impact development techniques. The flood risk infrastructure, each mechanism infrastructure for new towns it is imperative to

Secondary inspiration for IJburg to maintain its own serves a specific function within the primary, have goals for what the end-product will be water cycle emerged from the combined secondary, or tertiary infrastructure levels. (for example the districts of Almere modeled stress of subsidence, impervious surfaces, after Ebenezer Howard’s Garden City), the and age experienced by the surrounding Construction materials within each ability to provide for certain protection levels Amsterdam area (K. Spaan, personal mechanism allowed them to be categorized and standards, to be able function within a communication, June 6, 2017). Haveneiland on the structural to non-structural gradient budget, to understand and Steigereiland both employ green roofs by the discretion of their permeable to the feasibility of the project, and to maintain (extensive, intensive, and dike roof) impermeable surface ratio. For example, the adaptability for future changes. The which serve as the main mechanism to sand used within the IJburg toolkit is virtually adaptability aspect is the biggest departure combat rain events and act as additional 100% permeable, allowing nature and gravity from the planning of old towns, as new towns storage for excessive rainfall. The newer to do the work of infiltration when rain hits understand the challenges faced from climate proposed Centrumeiland within IJburg the surface versus the pumping stations change threats and place priority on making combines overland conveyance of utilized in Almere, which are virtually 100% communities that have room to adapt to new storm water with expanded low impact impermeable due to the utilization of concrete conditions. I development implementations within to artificially control water flow. The critical households such as: embedded rain pipes, dimensions exposed in each mechanism Jburg is a prime example for creating new open gutters, rain gardens, swales, permeable demonstrate the level of importance placed towns that can adapt to climate change Tertiary pavement, etc. (Atelier Groenblauw, n.d.). Low in spatially planning a new town. For example, conditions and provide innovative strategies impact development implementations will as setback standards for development and that differ from the typical Dutch polder become necessary components in reinforcing control of land uses ensures that stress solution. Although the creation of new both old cities, such as Amsterdam, and in placed on the overall flood infrastructure is archipelagos is mostly hampered by the the development of new cities as rain events maintained, monitored, and appropriate for budget and the integrity of the structure (as become more extreme and risk of inundation the specific mechanism employed in an area. it would not be realistic to make an elevated 158 increases. Although the mechanisms in place within 159 Almere ‘City of polder the size of the Flevoland), the forward- References processes in the southern United States. the purest water’: thinking strategy of creating new land sets Andersson, C. (2014). Rising tides: resilient Water, 2(3), 605-648.. bird eye view of a precedence for ingenuity when searching Amsterdam. Pierre, M. (1980). The new town movement Almere (image for strategies that reduce flood risk. While Ashley, S. T., & Ashley, W. S. (2008). Flood in Europe. The Annals of the American courtesy Waterschap Almere has the ability and plans to adapt to fatalities in the United States. Journal of Academy of Political and Social Science,451, Zuiderzeeland). future climate change through reinforcing and Applied Meteorology and Climatology, 47(3), 76-85. Retrieved from http://www.jstor.org/ enhancing regional dikes and implementing 805-818. stable/1043162 the Almere 2.0 plan, it can be debated that Atelier Groenblauw. (n.d.). Bouw groen Pleijster, E. J., van der Veeken, C., Jongerius, R., the creation of more new towns through en blauw: inspiratie voor rainproof en & Luiten, E. A. J. (2015). Dijken van Nederland. traditional polder development may not be natuurinclusief bouwen op Centrumeiland nai010 uitgevers. Slomp, R. (2012). Flood risk appropriate as sea-level rise due to climate Amsterdam. (n.p.): Amsterdam Rainproof. and water management in the Netherlands. change will enhance the stress placed on Climate change impacts. (n.d.). Retrieved WD0712RB205. existing critical flood risk infrastructure. from United States Environmental Protection Station de pompage Blocq van Kuffeler. Agency Digital Image. Mapio. n.d. 8 August 2017. < In conclusion, the framework for creating Emanuel, K. A. (2013). Downscaling CMIP5 http://mapio.net/o/4215974/> mechanisms within flood risk infrastructure climate models shows increased tropical is the most important take-away from the cyclone activity over the 21st century. PNAS, new towns case study that can be applied to 12219-12224 the greater Houston-Galveston Metropolitan H-GAC. (2012) H-GAC 13-County Flood Prone area, alongside an increase in protection Areas [map]. (ca. 1:40.) Houston-Galveston standards as the 100 year storm protection Area: H-GAC. level currently does not and will not uphold H-GAC. (2005) Population inside the 100 year safety for residents. First, the categorization floodplain (2005) [map]. (ca. 1:40.) Houston- of flood risks in Houston can be defined as Galveston Area: H-GAC. threats from flash floods, river floods, and H-GAC. (2005) Population inside the 100 year coastal floods (Ashley & Ashley, 2008), floodplain (2035) [map]. (ca. 1:40.) Houston- through understanding the multiple threats Galveston Area: H-GAC. residents experience from these three types Higgins, A. (2012, November 14). Lessons for of inundation a more appropriate protective U.S. from a flood-prone land. The New York critical flood risk infrastructure can be applied Times. in communities. While the New Towns Toolkit The storm resource. (n.d.). The Hurricane Ike is not a copy-paste solution for the Houston- impact report. Texas Engineering Extension Galveston Metropolitan Area, it can serve Service. as reference for how the area should place IJburg. (n.d.). Retrieved August 08, 2017, emphasis on critical flood risk infrastructure from https://www.iamsterdam.com/en/living/ within new and existing developments. about-living-in- amsterdam/neighbourhoods/ ijburg However, it needs to be noted that success infrastructure. 2017. In Merriam-Webster. of new town critical flood risk infrastructure com. Retrieved August 8, 2017, from https:// relies on the existence of and quality of its www.merriam- webster.com/dictionary/ larger regional protections, which ultimately infrastructure are the only “critical” infrastructure that IP Course Acce (2013). Climate change in matters, for if they did not exist the rest Almere: adaptation to climate change in the would fail. The co-existence of regional and Almere region. Velp, Gelderland: Municipality local flood risk infrastructure in support of Almere. with the context-geared mechanisms allow Kelder, E., Gersonius, B. & Hulsebosch, M., for greater flood risk management within (2012) Concept Gebiedsrapportage Eiland the new towns of Almere and IJburg. The van Dordrecht, versie 2.0 Meyer, H., Morris, framework employed in both new towns D., & Waggonner, D. (Eds.). (2009). Dutch serve as a precedence for how development dialogues: New Orleans, Netherlands: should be occurring in the Houston-Galveston common challenges in urbanized deltas. SUN. Metropolitan Area to ultimately secure local O’Driscoll, M., Clinton, S., Jefferson, A., Manda, economies and provide for the health, safety, A., & McMillan, S. (2010). Urbanization effects 160 and welfare of its inhabitants. on watershed hydrology and in-stream 161

Field visit by Dominique Herkes author to De Blocq van Kuffeler: explanations by local expert (left STRATEGIES FOR PUMPING STATIONS image) and view on two canals at the pumping station (right image). COMPARING DE BLOCQ VAN KUFFELER, ALMERE AND 17TH ST CANAL, NEW ORLEANS

Dominique is an undergraduate student at canals. New Orleans, however, deals with factor when deciding where and how much Rice University., Houston Texas. He is studying significant storm surge along the pump water should be pumped out of the canals civil and environmental engineering with a output. In addition, the pumping drivers are and into the surrounding lakes. focus in hydrology. essentially storm-related and the Corps of Engineers does not need to consider the As can be seen from the map in figure 1, same outside factors as the Netherlands. Almere lies along the Markermeer Lake, The Netherlands and New Orleans both deal Both systems are set up to pump out water freshwater lake created when the North with water distribution and flooding issues in the case of a storm, however, and are set Sea was drained from the area. In addition, associated with land lying under sea level. up as a part of a larger water and pumping the South Flevoland Polder is along the Like much of the country Almere, a new city network in order to keep the people and Ijsselmeer Lake. The height in both these in the South Flevoland, Netherlands, is largely property of the city safe. lakes is regulated by the National Water below sea level and relies on a systems of Authority of the Netherlands, Rijkswaterstaat. dikes to protect it from water flooding into Introduction of Sites Lake Marker is connected to Lake Ijssel, which the city. In addition to the dikes, however, This study was conducted as part of a team is connected to the North Sea. Unlike the a systems of pumping stations and canals investigating the flood resiliency capacities lakes, however, the polder itself is under the are needed in order to get water out of the of New Towns. This particular piece study authority of the regional water authority of polder. New Orleans deals with a similar investigates how the pumping occurring the region of Zuiderzeeland (Balkema). issue. The city is much older than Almere, at the Blocq van Kuffeler pumping station New Orleans, on the other hand, has been but outfall canals along Lake Pontchartrain in Almere, Netherlands compares to the around since the 1700s and is trying to also contain waters that are at risk to simply pumping station on the 17th street outfall modernize and update the flood protection flow into the city. Also like Almere, a system canal on New Orleans, USA. Both of these infrastructure. New Orleans lies just south of of pumps is needed to get water out of the areas lie completely or largely below sea Lake Pontchartrain, which is connected to the city. This study analyzes the pumping regime level. This low elevation creates a constant Gulf of Mexico through a small straight (Fig of the Blocq van Kuffeler pumping station danger in these areas from flooding. 2). The flood control infrastructure in the area in Almere, and compares it to the system in In this case, Almere is used as a case-study to is under the control of the US Army Corps of Figure 1: A map of New Orleans. It seeks to answer the question: examine the resiliency of New Towns. Almere Engineers. the Netherlands What is the decision making process behind is a town in the Flevoland province of the showing the South deciding to pump water in the South Netherlands (Fig 1). Problem Statement Flevoland Polder and Flevoland region and how does it compare to Both of these examined areas have dealt Almere highlighted the pumping at the 17th street outfall canal in This province includes two polders, areas with flooding in the past. In 1953, there was in red. New Orleans. To answer this question, a series of lands which used to be ocean, but have a flood in the Netherlands from the North of interviews were conducted around Almere since been reclaimed. In the case of the south Sea. The flood occurred after the dikes along Figure 2: A map in the Netherlands and US Army Corps of polder, the area was drained of salt water the North Sea at the time broke and water showing the location Engineers documents were read to determine and made into a lake before once again flowed into the land. The flood resulted in of New Orleans the pumping capabilities and decisions in the being reclaimed for usable land. This south 1836 people dying and more than 100,000 17th Street Canal. Results showed that the polder was reclaimed in two parts, one part people needing to be evacuated. In addition systems, despite seeming to deal with similar in 1957, and one part five years later in 1962. to the deaths, there was enormous damage issues initially are in fact quite different. Both This is why Almere is considered a new town. to buildings and property from the flood areas pump into a large body of water and The land in lies on has only been usable for (Gerritsen).This flood is what prompted deal with increased subsidence issues as a 55 years. This modern-nature of the town many of the improvements of Dutch flood possible result of pumping water. Almere, allowed it to be completely master-planned control infrastructure (Stoffels). This included however, has a relatively stable lake to pump since its conception, unlike older towns which creating a closed coastline along the North into, and various factions and conditions to have evolved over time. The Flevoland is Sea, resulting in the creating of Lake Ijssel 162 consider when pumping water out of the largely agricultural land, which is a significant and Lake Marker, which led the reclaiming of 163 Figure 3. the Flevoland Polders and the creation of the Netherlands around Almere to learn about Ijssel is simpler because the water level of Interviewees Zuiderzeeland Water Authority to oversee how the canal system in South Flevoland and both lakes are intensely regulated. Getting it. Almere was founded soon afterward, and Almere works. Meetings were held with the water out of Marker Lake requires that water Figure 4: A land flood prevention was a priority when creating following experts listed in fig. 3: In addition, be first let into Ijssel Lake, and then into the use map of the the town, despite much of the polder lying two tours of the Blocq van Kuffeler pumping North Sea. Consequently, it is simpler to South Flevoland between -3 and -6 meters below sea level station and a tour of Almere guided by Jikke simply pump water directly into the Ijssel Polder which also (Stoffels). Balkema and Bart Stoffels were conducted. Lake. display the pumping stations and canals Because of this low-lying nature of the polder, Research on the 17th street canal was The level water level in each canal is largely in the area. Almere a comprehensive pumping system is needed, conducted by reading US Army Corps of determined by the expected weather is marked with a both to pump water out if any breech or Engineers. The organization was reached out conditions. The following figure (fig 6) dashed red circle. flooding occurred, but also to pump out to with questions, but did not reply. displays the water level in the Low Canal water that is a result from seepage. The in cm during each of the scenarios. Figure reclaimed land of the polder is so low, water Results 7 shows the level in the Upper Canal for is constantly seeming up through the soil and Almere and the South Flevoland have a the same scenarios. Pumping stops and into the canals, where it must be pumped system of canals and pumping stations starts automatically at set water levels for out. The first pumping station build to drain designed to pump water into the adjacent each station depending on the weather to South Polder and one used to pump lakes. Unlike how it first appeared, the Blocq conditions and cost of energy. Cost of energy from the canals was the Blocq van Kuffeler van Kuffeler station is not the primary largely depends on time of day. Figure 5 is a pumping station. At the time it was built, it pumping station for the area, it serves as one translation key for the tables. was the largest pumping station in the world of four stations that serve the network. Fig 4. (de Visser). This study will examine how Shows a map of the other pumping stations The figures 6 and 7 show the pumping the pumping in the station is determined, and the canals connecting them. regime for the entire South Flevoland polder. and how it might compare to the pumping Essentially, water is allowed to go up when needed for the stations in New Orleans. As seen in the figure, there are two canals dry conditions are expected. When rain is serving the region. The south canal is the expected, the canals are pumped lower in New Orleans has also struggled with issues of Upper Canal and on average hold water at an preparation. Water is also allowed to be a flooding related to its low elevation. In 2005 elevation of -5.2 m NAP. The north Canal is little higher in the day time because energy the city was struck by Hurricane Katrina. the Lower Canal and has water at an average is usually more expensive then. By lowering More than 1,500 people lost their lives in of -6.2 NAP. The Blocq van Kuffeler serves the allowable height in the canals at night, Louisiana and even more perished in other both canals, but only as a backup. Two of the pumps are active when the energy is states (Sastry). The outfall canals, including its four pumps serve the Upper Canal and cheaper (Hoes). The Nachtvorst (spring frost) the 17th Street Canal, which run North-South two serve the Lower Canal. Wortman station condition represents when farmers must from Lake Pontchartrain, broke due to the serves the Lower Canal, and only works as spray their orchards with water in order to storm surge from the hurricane, despite the a back-up to even the Blocq van Kuffeler insulate them because the otherwise the water level being lower than the designed station. The other two stations serve as the blossoms would freeze and likely die. This maximum on the canals (Rogers, et al). After primary, daily use pumping station, Colijn for expected water use allows the water level to the breaches occurred, water was able to the Lower Canal, Lovink for the Upper. The rise. The figure also shows how many pumps flow into the adjacent low lying areas of the reasons for this are largely policy. act only as backups. For the Upper Canal, city. After the hurricane, the US Army Corps Both Colijn and Lovink contain electric Lovink is the primary pump and if water rises, of Engineers was given a budget to construct pumps, which run cheaper and cleaner than Colijn and eventually the pumps of the Blocq larger and more effective pumping stations diesel engines. In addition, they are both able van Kuffeler are used. On the Lower Canal, on the outfall canals. One of these pumping to pump water out of the canals directly both engines in Colijn are used before water stations sits between the repaired 17th Streel into Lake Ijssel, which connects to the North is pumped out of the Blocq van Kuffeler. Canal and Lake Pontchartrain. This system Sea. This is significant because there are was put in place since the 2005 hurricane, rules in place by Rijkswaterstaat concerning The actual height allowed in the canals is much later than the system in Almere and the the water quality in Lake Marker (Balkema). largely a result of needed water table height South Flevoland. This study with also examine Significant, historic issues of water quality in for agriculture. The canals could feasibly be how this pumping station is and is not like the the lake resulted in legislation designed to pumped lower than they are currently, but ones serving the South Flevoland Polder. prevent the lake from being further dirtied some crops depend on the water height again by water being pumped in. Lake remaining close to the ground level (Visser). Methods Ijssel, on the other hand, has relatively little In addition, pumping excessively speeds The study was largely conducted by doing legislation covering water being pumped in subsidence issues. Structures in Almere 164 interviews with experts in the region of the (Visser). In addition, pumping water into Lake were built to resist subsidence, by placing 165 Figure 5: translation foundational pillars deep in the ground As stated, however, the surge on Lake References for Figures 6 and 7 beneath the sinking top level. The road Pontchartrain is significant when considering Andersson, Chelsea, “Rising tides : resilient and pipe system, however, is susceptible to pumping out of the canal. The following Amsterdam” (2014). Honors Theses. Paper 25. Figure 6: The level sinking ground (Balkema). This is one area figure (fig 9) shows the variable lake height Arnold, G., Bos, H., & Doef, R. (Eds.). (2011). in the Lower Canal which may cause future policy changes along the canals. Water Management in the Netherlands (cm) at which about the allowable pumping in the polder (Netherlands, Rijskwaterstaat, Ministry of pumping stops (Balkema). As shown, the lake would only reach about 6 Infrastructure and the Environment). and starts for each feet on a 100 year storm or greater. Pumping Balkema, Jikke. Interview. June 7, 2017. station depending The height in the lake being pumped out of the 17th street canal is set to occur De Visser, Fred. Interview. June 12, 2017. on the weather too, however, is not usually a factor when until the lake elevation reaches 8 feet. When Duñeas-Osorio, Leonardo. A.M.ASCE, Buzcu- conditions. considering the pumping. The lake heights surge along the lake surpasses this, the canal Guven, Birnur, Stein, Robert, Subramanian, are regulated just as the canals are, so back stops pumping and essentially just becomes Devika. (2012). Engineering-Based Hurricane Figure 7: The level pressure affecting the pumping curves is not storage space until the surge decreases and Risk Estimates and Comparison to Perceived in the Upper Canal an issue. Between seasons, the height of the pumping can resume. Risks in Storm-Prone Areas. Natural Hazards (cm) at which two lakes changes by only 20 cm (Visser). Review. Volume 13. 45-56. pumping stops In addition, storm surge does not affect the Conclusion Gerritsen, H. (2005). What happened in and starts for each lakes much because they are separated from Ultimately, both New Orleans and Almere deal 1953? The Big Flood in the Netherlands in station depending the North Sea by dikes. with the threat of flooding that accompanies retrospect. Philosophical Transactions of the on the weather being located below sea level. Both cities are Royal Society A: Mathematical, Physical and conditions. Unlike the South Flevoland, Netherlands, protected by a levee or dike and depend on Engineering Sciences, 363(1831), 1271-1291. storm surge is one of the largest threats pumping to remove water from the canals. Hoes, Olivier. Interview. June 12, 2017. to cause flooding in New Orleans. During South Flevoland, however, has much more Meyer, H., & Waggonner, D. (2009). Dutch Hurricane Katrina, the south end of the lake regular pumping which occurs. The town Dialogs - New Orleans Netherlands (D. Morris, rose by almost 4.5m. During less intense and canals were built with very precise Ed.). Sun. hurricanes, it can still rise more than 3m requirements on the water height, creating a Rogers, J. D., Kemp, G. P., Bosworth, H. J., & (Meyer, et al.). This drastic changing in variability in the canals of only centimeters in Seed, R. B. (august 2015). Interaction between water level not only threatens to overtop variability. The canal storage is about much the US Army Corps of Engineers and the levees, it creates a problem for pumping more than flood prevent, but about supplying Orleans Levee Board preceding the drainage water back into the lake. Figure 8 shows the water to the nearby farmers. The main flood canal wall failures and catastrophic flooding configuration of outfall canals relative to protection is the series of dikes extending of New Orleans in 2005. Water Policy, 17(4), Figure 8: The three Lake Pontchartrain. This difficulty in pumping all the way to the North Sea which allow 707-723. outfall canals and during hurricanes is especially significant for regulated water levels in Lake Ijssel and Sastry, N. (2009). Tracing the Effects of Lake Pontchartrain because the high levels of rainfall often Lake Marker. New Orleans, on the other hand, Hurricane Katrina on the Population of New (Courtesy Nola.com) makes pumping necessary as the canals fill has recently upgraded its outfall canals in Orleans. Sociological Methods & Research, with rainwater. order to boost its flood resiliency. The canal 38(1), 171-196. height can fluctuate up to 6.8 feet and still Schleifstein, M. (2013, May 06). Construction The pumping regime of the pumping stations be deemed acceptable. This is due to the is to begin on permanent gate, pump along the New Orleans outfall canals is greater magnitude of rainfall which occurs in structures on New Orleans drainage canals. almost solely dependent on the height of New Orleans, as well as the variability in water Retrieved August 12, 2017. Lake Pontchartrain and expected rainfall. height in Lake Pontchartrain. Spaan, Kasper. Interview. June 7, 2017. The US Army Corps of Engineers has given Stoffels, Bart. Interview. June 8, 2017. numbers for how and when the three outfall Ultimately, the new town nature of Almere US Army Corps of Engineers, Department canals should pump, based on the expected allowed it to be much more precisely of Defense. (2008). Phase 2 Conceptual height of Lake Pontchartrain. The acceptable regulated than New Orleans. By closing of Design Service For Permanent Pump Stations height of water in the 17th street canal is the polder from the North Sea with a series and Canal Closures at Outfalls: Operating Fig 9: The between 8 and 13.3 ft (US Army Corps of of gates and placing extensive infrastructure Scenario Analysis Final Report. elevation of Lake Engineers). When rainfall or hurricanes are to prevent lake height variability, pumping is Visser, Marijke. Interview. June 12, 2017. Pontchartrain for expected, the canal would be pre-pumped allowed to depend solely on water level in the Zhou, Zhengnan, Qu Lei, Tao Zou. (2015). storms of various to a lower level, closer to 8 ft. In addition, canals and expected weather. New Orleans, Quantitative Analysis of Urban Pluvial Flood return periods the walls of the canal are designed to hold by contrast, is right against the lake which Alleviation by Open Surface Water Systems up to 18 feet of water in times of emergency threatens to flood it. As a result, pumping in New Towns: Comparing Almere and Tianjin without failing (US Army Corps of Engineers). depends on not only the canal water level Eco-City. Sustainability. This means there will always be at least 4.7 and expected weather, but also the height in 166 feet of storage in the 17th street canal. Lake Pontchartrain. 167 Image left: Image below NSF-PIRE 2017 Case #2 Case study location. Maeslant Barrier in The Nieuwe Waterweg, in ROTTERDAM PORT: VULNERABLE INFRASTRUCTURE #3 shipping route in O port of Rotterdam. (Photo Courtesy Rijkswaterstaat). CASE COMPARASON : HOUSTON PORT, TEXAS, USA

This case study examines flood risk and related consequences for Here are some examples of Research Questions (RQ) that could (but infrastructure networks in the Rotterdam Port and City area and not must) serve as a guide to further development. compares them with similar issues faced by the Houston Port and City. In both locations, unembanked areas near the river (or bayou) RQ 1: What are the consequences of climate change or extreme contain critical infrastructure, along with residences and businesses. weather on the area; how does it influence the various infrastructure These areas are subject to regular flooding from rainfall-runoff, high networks present in that area? river flows, and coastal storm surge. In addition, these areas are RQ 2: What are the most important and fragile infrastructure expected to become even more vulnerable to flooding in future due to components? sea level rise, more frequent and intense precipitation, and increased RQ 3: Why are these components fragile and how can they be made river discharge. However, the physical characteristics of the two areas less vulnerable? differ significantly, e.g., the sub-surface consisting of clay, peat, and RQ 4: How is post-disaster debris management planned and sand in Rotterdam, and clay in Houston; and differences in current implemented? and future hydraulic boundary conditions. These and other differences RQ 5: Which types of debris could be present in the Port of provide an interesting opportunity for comparative research. Rotterdam during flood events; What is the structural behavior of ASTs under water-driven debris impacts? This case study includes a focus on the vulnerability of above ground RQ 6: What policy or planning instruments can be used or developed storage tanks (ASTs) to both river and coastal flooding. These large to decrease vulnerability of residential areas near industrial ports to cylindrical structures are used to store hazardous materials and many flooding? of these ASTs are located in or near flood-prone areas with limited protective measures in place. While a recent study has shown that the ASTs in Rotterdam are not vulnerable to hydrostatic effects under current flood conditions, ASTs could still be vulnerable to water-driven debris impacts. Current research into the vulnerabilities of ASTs within the Port of Houston will serve as a comparative case.

168 169 Figure 1. Overview Carl Bernier of the Port of Rotterdam IMPACTS OF WATER DRIVEN DEBRIS IMPACTS ON ABOVE GROUND STORAGE TANKS ROTTERDAM PORT

Carl is a doctoral student in the Department the United States (US). For instance, more the European petrochemical industry. More of Civil and Environmental Engineering at than 26.5 million liters of crude oil were than 3,100 ASTs are located in this port, and Rice University. spilled due to the failure of ASTs during many ASTs are located in flood zones with Hurricanes Katrina and Rita (Godoy 2007; limited protective measures. A previous Sengul 2012). In addition to hurricane events, study (Kameshwar 2016) has assessed the Abstract similar damage to ASTs were also observed vulnerability of ASTs in the Port of Rotterdam This study investigates the structural during tsunami events in India and Japan to hydrostatic loads. Given the low flood behavior of aboveground storage tanks (Goto 2005; Naito 2013), and flood events levels in the Port of Rotterdam, failures due (ASTs) to water- driven debris impacts and around the World (Cozzani 2010). Post- to hydrostatic effects are not likely to occur. the potential for damage from such loads investigation reports have shown that the However, water- driven debris impacts can be in the Port of Rotterdam. Flood conditions four most common failure modes of ASTs are: of concern as past observations have shown are found to be adequate for debris impacts (i) global buckling (or crushing) of the tank that they can cause serious damage to ASTs in the Port of Rotterdam. Floating cars and shell due to excessive wind or hydrostatic even for low flood or surge level and low empty shipping containers are the most likely pressure; (ii) dislocation and flotation due water velocity (Ko et al. 2015). As a matter of debris to affect ASTs. Finite element analyses to excessive buoyancy force from the flood; fact, debris are often considered as the last are performed to assess the potential for AST (iii) dislocation and sliding due to excessive possible damage mechanism when a tank damage if a debris impact occurs. Results hydrodynamic force; (iv) local buckling of has not already floated of buckled due to Figure 2: Flood indicate that cars are not likely to induce the tank shell due to impacts from floating the water forces (Naito 2013). This study first conditions in the damage to ASTs while shipping containers objects. starts by presenting the flood conditions and Port of Rotterdam could induce damage. A regression model the potential for debris impacts in the Port predicting the potential for damage from Despite the considerable risks associated to of Rotterdam. Then, finite element models shipping container impacts as a function of these structures, the knowledge regarding are developed to assess damage to AST if the debris and AST properties is developed. the above failure mechanisms is limited. Most impact occurs. Finally, results of these models Finally, this model is used to assess the of the existing literature is limited to wind are used to identify ASTs that could suffer conditional probability of damage of ASTs buckling (Godoy 2016). Moreover, actual damage from debris impacts in the Port of in the Port if a debris impact occurs. Overall AST design codes (API 620 (API 2002) Rotterdam. It is important to note that the results indicate that few ASTs are vulnerable and API650 (API 2013)) only have design objective of this study is not to quantify but this number could significantly increase provisions for wind loads. Recent studies the amount of debris or to estimate the due to sea level rise and changing flood (Bernier and Padgett 2017; Kameshwar probability of an AST to be hit by a debris conditions. and Padgett 2017) have addressed the but rather what would happen if a debris vulnerability of ASTs to buckling and flotation impact occurs. Figure 3: Number Introduction under hydrostatic and hydrodynamic loads. of ASTs in the flood Aboveground storage tanks (ASTs) are However, the failure mechanisms and the Flood conditions in the port of Rotterdam zone and for three typically used in coastal areas to store large vulnerability of ASTs under debris impacts In order to investigate water-driven debris different years quantities of bulk chemicals such as oil and still need to be addressed. As such, the impacts, it is required to know the flood gas. These structures are constructed of thin- objective of this study is to evaluate the conditions (flood elevation and flood wall steel shells forming a vertical cylinder. structural behavior and potential damage velocity) within the Port of Rotterdam. Due to their geometry, ASTs can efficiently of ASTs in industrial areas and subjected to The Maasvlakte and Europort regions of withstand the pressure from internal liquid. water-driven debris impacts. the Port are located outside the dikes and However, this geometry also leaves them gates system. However, all ASTs are located vulnerable to external loads such as wind, The Port of Rotterdam is selected as a case 5.5 to 7 m above the mean sea level and surge or flood, wave impacts, and debris study; an overview of the Port is presented are protected against wave actions by an impacts. This vulnerability was highlighted in Figure 1. The Port of Rotterdam is the 11-km sea defense (Loman et al. 2012). Given 170 in past hurricanes events to touch ground in largest port in Europe and is a major hub for that the 10,000-year surge level would be 171 Table 1: of 5.3 m, these ASTs are not vulnerable to Potential debris were identified in the Port study as many experimental studies of debris Debris properties flooding or debris impacts. While the ASTs of Rotterdam using aerial imagery. First, impacts (including shipping containers) have in the Botlek region are protected by dikes it was possible to observe that there are proven its validity (Piran Aghl et al. 2014; and the Maeslant barrier, their elevations very few trees or wooden structures within Ko et al. 2015; Riggs et al. 2014). The impact range between 0.9 to 4 m above sea level. the Port. However, many cars and shipping force (F) is: Given a failure of the Maeslant barrier or containers are present at a close distance of the overtopping of a dike, the ASTs could ASTs. Two major car terminals (for import/ be subjected to surge and potential debris export) could be identified in the flood zone

impacts. Deltares (2015) performed a of the Botlek region; they are circled in red In this equation, vI is the debris velocity at probabilistic flood assessment of this region in Figure 2. Parking lots are also dispersed at impact; k is the stiffness of the debris; and m Figure 4: Debris and developed flood maps for return periods many locations within the Port. Moreover, two is the mass of the debris. The impact velocity impact force as ranging from 100 and 30,000-year. They shipping container terminals were identified; of the debris is assumed to be the same as a function of the also considered sea level rise by developing they are circled in yellow in Figure 2. Using the water velocity. Figure 4 shows the impact velocity. maps for 2015, 2050, and 2100. In this study, the methodology presented in Korswagen forces for a 1,200-kg car and a 20-ft shipping only the 10,000-year flood is considered (2016), buoyancy and drag calculations container using the above equation. This as it represents the typical hazard level in were also made to verify if cars and empty figure clearly shows the higher potentially the Netherlands. The flood conditions are shipping containers could easily float with for damage from shipping containers. This is summarized in Figure 2. Flooding in the the above flood conditions. Results indicate mainly due to the higher stiffness of shipping Botlek area is mainly due to the failure of that water levels above 0.4 m are required containers. Shipping containers are designed the Maeslant barrier or the overtopping of for flotation of such debris. Finally, the flood to withstand impacts without suffering any a low point of a highway located on top of conditions are not severe enough for larger major deformations while cars are designed a dike. The Maeslant barrier is assumed to or heavier debris such as vessels or concrete to crush on impact and dissipate energy. fail (not closing or structural failure) one objects to pose a threat for ASTs. Based on the ASCE7 (2010) standard,

time every 100 times it is closed. Flood The structural analysis presented in the next impact durations (td) of 0.025 to 0.050 s depths vary between 0.5 and 2.0m, the two sections required a good approximation are assumed for both type of debris. From flood velocities are between 0.5 and 2.0 of the debris properties. Car properties in experimental results, the impact force time m/s, and such a flood would last at least the Netherlands could be extracted from history is assumed to be triangular (Riggs et a day. Based on results from Korswagen Korswagen (2016), while properties of al. 2014). The maximum impact force occurs

(2016), these flood conditions are adequate shipping containers were obtained from at td/2 while no more force is applied at td. for debris impacts to occur. More precisely, the ISO-668 (2013) standard; intermodal above 0.5 m of surge, debris impacts are containers are assumed. Properties of both Numerical modeling of debris impact Figure 5: LS-Dyna of importance. The number of ASTs in the types of debris are presented in Table 1. To assess the potential for damage from model of an AST. flood zone are presented in Figure 3 for All debris impacts considered herein are debris impacts, finite element models (FEMs) different surge elevations. The dashed red assumed to be frontal as it is the worst- are developed using the software LS-Dyna. rectangle highlights the ASTs that could case scenario and given the numerous The numerical model of an AST with a potentially suffer from debris impacts. There uncertainties associated to oblique impacts. diameter of 15 m and a height of 10 m is are approximately 200 ASTs that could be Car impacts are assumed to occur at the shown in Figure 5. The ASTs are designed affected by debris impacts in 2015. However, bumper level. Finally, there is no uncertainty according to the American Petroleum as seen in Figure 3, this number significantly regarding the dimensions of shipping Institute (API) 650 design standard. Multiple increases when considering sea level rise and containers as dimensions are usually shell courses with variable thickness are used a changing climate; more than 600 and 800 standardized in large ports. to model the tank wall. ASTs are designed ASTs could be vulnerable to debris impacts with a conic roof supported by rafters. A top in 2050 and 2100 respectively. This highlights To assess the structural behavior of an AST angle and stiffening rings are also provided the importance of further investigating the under debris impacts, it is critical to estimate to stiffen the shell when required by the effects of water-driven debris impacts on the force from the impact. Models for debris standard. The shell courses are modeled with ASTs. impact forces are usually derived from rigid- quadrilateral shell elements. The roof shell body impact dynamic and experimental is modeled with triangular shell elements Type of potential debris data. Three main approaches are currently while the top angle, stiffening rings and In coastal regions, water-driven debris available to estimate debris impact forces: rafters are modeled with beam elements. mainly consists of: wood logs, trees, and (i) the impulse-momentum approach; (ii) All the components are modeled using an poles; empty shipping containers; cars the work-energy approach; and (iii) flexible elastoplastic material model with kinematic or other vehicles; barges and vessels; impact approach. There is no consensus on hardening and with the physical properties construction debris from wood structures; which method is optimal (Ko et al. 2015). The of steel. The base of ASTs is fixed in all 172 and stone and concrete objects (Naito 2014). lexible impact approach is adopted in this directions. Finally, since multiple studies 173 Figure 6: Example of (Godoy 2016) have shown that considering whole range of AST geometries and debris Network Toolbox. With the training samples, Conclusions displacement time imperfections is critical for an accurate properties in the Port of Rotterdam, a the ANN predicts the potential for damage This paper presented an investigation of history at debris estimation of the behavior of storage tanks, regression model predicting potential for with an accuracy of 89.8%. With the test water-driven debris impact on aboveground impact location. global imperfections of the tank shell are damage as a function of the AST and debris samples, the ANN accuracy is of 94.0%. storage tanks and an application to the Port also included in the numerical model using parameters is developed. The development Additional analyses indicate that the water of Rotterdam. First, flood conditions and the method proposed by Kameshwar and of a regression model requires enough depth (and location of debris impact) is potential debris were investigated in the Port. Padgett (2015). This method uses two training points to efficiently span the space the most influential parameter to estimate It was shown that flood level and velocity dimensional Fourier series expressions with of the parameters. To do so, Latin Hypercube potential for damage. are adequate for debris impacts to occur random coefficients to model imperfections. Sampling (LHS) is used to generate a space at AST locations. Cars and empty shipping filling experimental design (McKay 1979). The Potential for debris-induced damage in the containers are also present in large number Internal liquid and external surge loads parameters considered in the LHS design port of Rotterdam at close distance to ASTs and could become are modeled using a hydrostatic pressure and their ranges are summarized in Table 2. With the previous regression model, it is now potential floating debris during a flood. Using distribution. Hydrodynamic effects of the The range of density corresponds to oil and possible to estimate the potential for damage these results, finite element models were then surge (current only, not waves) are also gas products while the other ranges of AST of ASTs located in the Port of Rotterdam coupled with an Artificial Neural Network to considered. These loads are applied in a properties are derived from the database to shipping container impacts. For a given derive a regression model to predict the Figure 7: Example static manner while the debris impact force is in Kameshwar (2016). The uncertainties AST, it is possible to know D and H from the potential for damage to ASTs if debris of AST deformations applied in a dynamic manner. Impact force is associated to other debris properties database developed in Kameshwar (2016) impact occurs. Results indicates that car during and after assumed to occur at the surge level, and the presented in Table 1 are directly propagated while the water depth (S) can be obtained impacts do not pose a threat for the flood impact with a total force obtained from Eq. 1 is distributed in the analysis. A total of 500 samples are from the flood maps developed by Deltares conditions present in the Port of Rotterdam. shipping container over the contact area between the debris generated; 450 are training samples while (2015). However, shipping container impacts could and the AST. Since only frontal impacts 50 are test samples. Each sample has a induce severe damage to ASTs in the Port. are considered herein, the contact area is different combination of parameters and a However, prior to a storm, it is not possible With this regression model, the probability

simply the debris width times the debris finite element analysis, as described above, is to exactly know L and ρL, for a specific AST. of damage to shipping container impacts

height. The LS- Dyna implicit integration performed to assess if damage occurred or Moreover, the mass (mContainer) and the velocity was then assessed for all ASTs located in scheme is used to compute the deformation not. This process is repeated for both types (U) of the debris are uncertain; Deltares (2015) the Port of Rotterdam. Very few ASTs are and displacement of ASTs during and after of debris, car and shipping containers, for a provides maximum water velocity but they currently vulnerable if impact would occur. impact. Displacements are also recorded at total of 1,000 analyses. For cars, none of the do not necessarily occur with the maximum However, the number of vulnerable ASTs is impact locations, as shown in Figure 6, to 500 samples suffered damage under impact. flood level. Thereby, these parameters likely to considerably increase in the next determine the potential for damage. Thus, cars do not seem to be of concern for are considered as random variables, and decades due to sea level rise and changing ASTs, and no regression model was derived. a probability of suffering damage can be flood conditions. These results highlight the Table 2. Range of Using a similar approach to HAZUS (1997), However, for shipping containers, more than obtained through Monte Carlo Simulation need to further investigate the likelihood for parameters in the damage levels are defined based on the 200 samples suffered damage. In that case, it (MCS) for each AST located in the Port of debris impacts in the Port (i.e., the probability LHS design reparability of ASTs. As such, if the AST was possible to derive a regression model. Rotterdam. Figure 8 (next page) shows the of an AST to be actually hit by a shipping remains completely elastic during and after results for the water levels in 2015. Results for container) and to investigate mitigation the debris impact, the AST is assumed to An Artificial Neural Network (ANN) (Murphy the water levels in 2050 and 2100 are also measures to protect ASTs against such loads. be undamaged. However, if yielding occurs 2012) is employed to obtain a regression shown in Figures A1 and A2 (in annex). Nonetheless, this study has taken a first step and permanent deformations appear after model of the potential for damage from to evaluate the structural behavior of ASTs impact, the AST is assumed to be damaged. shipping container impacts. Attempts to It is important to remind that these results do under debris impact loads and provides key Such damage levels are commonly used in obtain simpler and closed-form regression not include the probability of an AST being insights for future probabilistic studies of the literature (Fabbrocino et al. 2005; Wei et models (such as logistic regression and actually impacted by a shipping container. tank performance under multi-hazard loads. Figure 9: Evolution al. 2015). An example of AST deformations support vector machine) were unsuccessful; They are conditional probabilities of damage of the number of for a shipping container impact are shown these models yielded accuracy lower than if impact occurs. Figure 9 also shows the Ackowledgements ASTs vulnerable to in Figure 7. In this figure, the structure 70%. Different ANN architectures were evolution of the number of ASTs vulnerable The author gratefully acknowledges the shipping container displacements were amplified to be visible. explored and a single-layer ANN with 40 to shipping container impacts (probability support of this research by the National impacts Figure 7a) shows the maximum deformation neurons was selected. The inputs of the ANN of damage over 0.50). Currently, very few Science Foundation Coastal Flood Risk during impact while Figure 7b) shows the are the water depth (S), the water velocity ASTs are vulnerable if shipping container Reduction PIRE program. The author also residual deformation after impact; this AST (U), the AST diameter (D), the AST height impacts occurs. However, this number thanks Bas Jonkman, Bas Hofland, Jeremy suffers damage. (H), the internal liquid height (L), the internal significantly increases with sea level rise and Bricker, Paul Korswagen, and Joost de Nooijer

liquid density (ρL), the steel design stress (Sd), changing flood conditions. This highlights for their inputs and comments on this project.

Model for prediction od damage and the shipping container mass (mContainer). the importance of further investigating this Any opinions, findings, and conclusions or A single finite element model can only The output of the ANN is the potential for problem to assess the likelihood of an AST recommendations expressed in this paper are provide information for a specific AST damage (undamaged or damaged) for an being in the trajectory of a floating shipping those of the author and do not necessarily

and a specific debris. Thus, to cover the AST with the specified D, H, L, and ρL. The container and to protect adequately ASTs reflect the views of the sponsors. 174 ANN is trained using the Matlab Neural during flood events. 175 Figure 8: Probability REFERENCES Kameshwar, S., and Padgett, J.E. (2017). Riggs, H.R., Cox, D.T., Naito, C.J., Kobayashi, of damage for American Petroleum Institute (API) (2002). “Storm surge fragility assessment of M.H., Piran Aghl, P., Ko, H.T.-S., and Khowitar, shipping container Std 620: Design and construction of aboveground E. (2014). “Experimental and Analytical Study impacts in 2015 large, welded, low pressure storage tanks, storage tanks.”, Structural Safety, In review. of Water-Driven Debris Impact Forces on Washington, DC. Kameshwar, S., (2016). Understanding Structures.”, J. of Offshore Mechanics and American Petroleum Institute (API) (2013). vulnerability and acceptable flood risk to Artic Engineering, 136, 041603. 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Lei Bu Ike flood damage and Area outside the dikes highway and interstate in Port of Rotterdam. impacted in Port of Image courtesy: VULNERABILITY STUDY AND COMPARISON OF Galveston. Google maps. TRANSPORTATION INFRASTRUCTURE

ROTTERDAM PORT

Lei is a PhD student in the Department Problem Statement Flood Damage Data of Civil and Environmental Engineering The Port of Galveston is the port of the Flood damage historical data of Port of at Jackson State University and Graduate city of Galveston, Texas. It is located on the Galveston was collected from the previous Research Assistant at Institute for Multimodal upper Texas coast on the eastern end of research at the Texas A & M, USA. Flood Transportation. Her current research focuses Galveston Island, and 15.0 km from the open damage historical data of Port of Rotterdam on coastal transportation network reliability Gulf or approximately 30 minutes sailing was collected from the research results of the and flood risk analysis. time. According to the statistics, in 2009, ENHANCE project accomplished in Europe there was 944 vessel arrivals and 788,931 (5). passenger traffic. Annual cargo tonnage was 8,883,069 tons and annual container volume Figure 1 presents the flood damage and was 83, 643 containers (1, 2). Transportation highway and interstate highway impacted in Introduction infrastructure of highway in the port includes Port of Galveston in Hurricane Ike. Highway Transportation infrastructure including roads highway 87, highway 275, highway 342 and 87, highway 275, highway 342 and interstate and railways in a port gives the port the best interstate highway 45. highway 45 are impacted by showing the internal accessibility. An extensive intermodal higher flood damage. Figure 2 shows the transportation network of road and rail also The port of Rotterdam is the largest port area outside the dikes in Port of Rotterdam. gives the port the best possible connections in Europe, located in the city of Rotterdam, Highway A15 and road Moldauweg located to the hinterlands. As a part of coastal area, Netherlands. According to the statistics, in this area are impacted by storm, as shown both of the Port of Galveston and Port there was 36,315 sea ships of vessel arrivals in in Figure 3. Water depth results with return of Rotterdam have the challenges for the 2008. Annual cargo tonnage was 441.5 million period of 100 year in 2010 and in 2050 in storm surge risk, hence the transportation tons in 2012 and annual container volume was Figure (a) and (b), water depth results with infrastructure in the port is vulnerable. This 11.87 containers in 2011 (3, 4). Transportation return period of 1000 year in 2010 and in project aims to study on the vulnerability infrastructure of highway or roadway in the 2050 also show that highway A15 and road of transportation infrastructure for the two port includes N15, A15, and road Moldauweg. Moldauweg are impacted by storm. ports to find the potential inundation height of roads or highways. The comparison of Hurricanes are the key population of storm Highway and Road Elevation Data Figure 3a and 3b. Figure 3c and 3d. the vulnerability in the two ports are also inundation events on the Texas coast, Elevation data of highway in Port of Water depth with Water depth with discussed. This project will contribute to the whereas winter storms are the key population Galveston was collected from Coastal return period of 100 return period of 1000 base work for developing transportation of storm inundation events for the Dutch Altlas (6) released by the Center for Texas year in 2010 (3a) and year in 2010 (3c) and infrastructure risk reduction strategy for the coast. So it is necessary to find the water Beaches and Shores (CTBS). Elevation 2050 (3b). 2050 (3d). Port of Galveston and other ports. levels for the same set of return period data of highway in Port of Rotterdam was for the Port of Galveston and the Port of collected by KML file from google earth and 3a 3b 3c 3d The project is organized as follows: the Rotterdam, and then get the inundation processed using analyst tools in ArcGIS. Problem Statement section describes the value for the transportation infrastructure at Figure 4 and Figure 5 shows the locations characteristics of the Port of Galveston and selected locations considering the elevation selected to collect the elevation data. For the the Port of Rotterdam, and the objectives characteristics. Port of Galveston, there are four locations of the projects are also introduced. Data selected on I-45. There are three locations collection including flood damage data, The objectives of the project are: (1) Collect on highway 87, highway 275, and highway elevation data, and water level statistics flood damage data in both of the ports to 342, respectively. For the Port of Rotterdam, data are presented in the part followed. determine the transportation infrastructure there are three locations on A15 and road Then followed by the part of infrastructure with the most potential vulnerability, and; (2) Moldauweg, respectively. vulnerability analysis and comparison. Finally, determine the potential inundation height at conclusions are summarized and future work the selected locations of the transportation 178 is highlighted. infrastructure in both of the ports. 179 Figure 4. Table 1 (below) shows the elevation value at According to the previous research, the of flood damage, elevation, and water level Locations selected each location of the two ports. The elevation seal level rise is 73 cm for present day in statistics are collected and presented. for the Port values of highways in the Port of Galveston Galveston Bay and 0.22 cm for each year The potential vulnerable transportation of Galveston are lower than that in the Port of Rotterdam, Hoek van Holland. The adjusted mean water infrastructure are founded and inundation (corresponding except that for interstate highway 45, level considering the sea level rise is shown height are calculated considering the seal graphs next page). the elevations values are higher for three in Table 3. The adjusted mean water levels level rise. Image courtesy: locations among four locations. of the Galveston Bay are higher than that Google maps. of Hoek Van Holland by showing the larger Based on the study results, the following values. conclusions could be drawn: Table 1. (1) The elevation values of most of highways Elevation at each location of the two ports Infrastructure Vulnerability Analysis and in the Port of Galveston are lower than that in Comparison the Port of Rotterdam; Port Facility Location Elevation The infrastructure inundation height is (2) The adjusted mean water levels of the Galveston I-45 1 223 determined by equation (1). Galveston Bay are higher than that of Hoek 2 730 Van Holland by showing the larger values,

3 601 H fin = H mwl - H felv (1) and; 4 717 (3) For the Port of Galveston, highway 87

Hwy 87 1 222 Where, H fin is the infrastructure inundation and highway 275 are the most vulnerable 2 259 height above the ground level, cm; Hmwl infrastructures, while I-45 and highway 342 3 239 is the mean water level, cm, and; H felv is are vulnerable at some locations for some Hwy 275 1 291 the infrastructure elevation level, cm. The return periods. For the Port of Rotterdam, 2 164 inundation results of the two ports are road Moldauweg is more vulnerable than A15. 3 146 presented in Table 4 and Figure 6-Figure 12. Hwy 342 1 217 This study collected flood damage data in 2 205 For the Port of Galveston, highway 87 both of the Port of Galveston and the Port of 3 506 and highway 275 are the most vulnerable Rotterdam to determine the transportation Rotterdam A15 1 591,6 infrastructures by showing the inundation infrastructure with the most potential 2 583.7 height values which are larger than zero for vulnerability, and determine the potential 3 599.8 all the return periods, and I-45 and highway inundation height at the selected locations Moldauweg 1 359.1 342 are vulnerable at some locations for of the transportation infrastructure. How to 2 346.6 some return periods by showing some apply the methodologies in this study to 3 527.9 inundation height values larger than zero more transportation infrastructures in the two Figure 5. while some values just equal to zero. For ports or other ports in US and Netherlands Locations selected the Port of Rotterdam, road Moldauweg is will be the research work in the future. for the Port Water Level Statistics Data more vulnerable than A15 by showing some of Rotterdam Hurricane water level statistics data for the inundation height values larger than zero for Acknowledgements (corresponding different return period in Port of Galveston return periods of 100 yr, 200 yr, 500 yr, and The author thanks NSF PIRE Coastal Flood graphs next page). was computed by U.S. Army Engineer 1000 yr, respectively. Risk Reduction Travel Program for supporting Image courtesy: Research and Development Center (ERDC) the field research in the Netherlands 2017. Google maps. at the station Galveston Bay based on The inundation values for both of the The author thanks Dr. Bas Jonkman, Dr. two hundred of hypothetical hurricanes ports also show that the transportation Mark Voorendt, and Dr. Matthijs Kok at Delft with adequate treatment of the variable infrastructure in Port of Galveston is more University of Technology in Netherlands, Dr. hurricane parameters, tide and other sources vulnerable than that in Port of Rotterdam Robin Nicolai at Delft HKV Consultants in of uncertainty. The estimated return period by showing the higher inundation value for Netherlands, Dr. Bruce Ebersole at Jackson water levels in Port of Rotterdam was return periods compared the values larger State University in US, and Dr. William Mobley collected from the previous research at Delft than zero. at Texas A&M University in US for helping University of Technology, Netherlands using to collect data. The author also thanks long record of measured water level at the Conclusions graduate students Mr. H.C. (Han) de Jong , Mr. station Hoek van Holland from year 1863 to This project studies on the vulnerability of Feihong Liu at Delft University of Technology year 2013. Mean water levels for return period transportation infrastructure for the Port of in Netherlands, Mr. Carl Bernier at Rice of 10 year, 20 year, 50 year, 100 year, 200 year, Galveston and the Port of Rotterdam and find University, and Ms. Emily Fucile at Texas A&M 500 year, and 1000 year without considering the potential inundation height of roads or University for helping to well understand the sea level rise (SLR) are shown in Table 2, highways. The comparison of the vulnerability data. 180 90% confidence level. in the two ports are also discussed. Data 181 Figure 6. Figure 7. Figure 8. Figure 9. Inundation height Inundation height Inundation height Inundation height results of return results of return results of return results of return period 10 year for period 20 year for period 50 year for period 100 year for both of the ports. both of the ports. both of the ports. both of the ports.

Figure 10. Figure 11. Figure 12. Inundation height Inundation height Inundation height results of return results of return results of return period 200 year for period 500 year for period 1000 year for both of the ports. both of the ports. both of the ports.

References 1. Port of Galveston. http://www. portofgalveston.com/. Accessed in August, 2017. 2. Wikipedia, Port of Galveston. https:// en.wikipedia.org/wiki/Port_of_Galveston. Accessed in August, 2017. 3. Port of Rotterdam. https://www. portofrotterdam.com/en. Accessed in August, 2017. 4. Wikipedia, Port of Rotterdam. https:// en.wikipedia.org/wiki/Port_of_Rotterdam. Accessed in August, 2017. 5. Jeroen Aerts and Jaroslav Mysiak. ENHANCE. Novel Multi-Sector Partnerships in Disaster Risk Management. 2016. 6. Coastal Atlas, www.texascoastalatlas.com. The Center for Texas Beaches and 182 Shores (CTBS). Accessed in August, 2017. 183 Figure 1. Figure 2. Emily Fucile Sanchez Rotterdam Port Houston Port study study area. area. SOCIAL MIXING AND FLOOD VULNERABILITY

COMPARING SOCIAL VULNERABILITY BETWEEN THE PORTS OF HOUSTON AND ROTTERDAM

Emily is a graduate student in Marine hazards and affect their ability to respond age, gender, race, and socioeconomic status Resource Management at Texas A&M (Cutter, 2003). There is an unequal adaptive (Cutter, 2003). University at Galveston. Her research focuses capacity for socially vulnerable areas because on household vulnerability to coastal flooding of spatial inequalities which are linked Elderly and children are the most vulnerable in Galveston-Houston area and exploring to social vulnerability. Of natural disaster groups in disaster events. Children lack the community-based resilience indicators that events flooding, including storm surge ability to protect themselves because of foster quick and sustainable recovery from events, are globally the costliest. Using the lack of resources and information to cope catastrophic incidents... spatial distribution of populations for flood with the situation (Barry E Flanagan, 2011). mitigation is an idea that strays from the While elderly people are generally inflicted typical use of physical flood barriers. While with cognitive challenges which may hinder there are areas which are vulnerable to their ability to prepare and respond (Barry E flooding and cannot simply be moved, social Flanagan, 2011). Abstract mixing and physical barriers can minimize the For this research areas which are situated vulnerability for high risk areas. Marginalization of Racial and Ethnic within five kilometers of the Port of minorities effect these groups in all stages Rotterdam and the Port of Houston For this report the differences in spatial of disaster. Inequities for these groups are are examined. Social vulnerability, and distribution of socially vulnerable populations typically social, political, and economic, concentrated disadvantage are mapped for the Rotterdam and Houston port, with effecting their ability to prepare, cope, in order to make assumptions about respect to critical industrial infrastructure, respond and recover from disaster. The preparation and recovery ability. Social are explored (study areas see Figures 1 and largest effect of these inequalities is seen vulnerability is then compared to that of the 2). These sites are chosen for comparison in housing. Discriminatory housing is usually Houston port area to analyze how differing because of their similarity in flood potential, more densely occupied, less structurally social policies effect vulnerability. It is found storm surge and rain events, and social sound, and in areas which are more that the amount of socially vulnerable strata due to occupation. Policies which susceptible to hazard (Barry E Flanagan, 2011). populations situated near the Port of promote social mixing and heterogeneity in Rotterdam is significantly less than the Port housing stock are examined as a mitigation Socioeconomic status affects how groups of Houston. It is also found that there is a tool. Understanding the implications of perceive hazards, inherently their ability to decrease in concentrated disadvantage over these policies can aide in improving disaster prepare for disasters by purchasing insurance a 7-year period in the Port of Rotterdam resilience for Gulf Coast cities, improving the and quality housing, as well as their ability following revitalization policy. odds of protecting people and property in to recover after a disaster (Alice Fothergill, anticipation of disasters. 2004). Introduction The idea of natural disasters being equal Social Vulnerability Social vulnerability is not one dimensional, opportunity events neglects the political, Social vulnerability is the susceptibility of rather it is distributed in space. The demographic and economic discrepancy groups which are marginalized, by socio- understanding of spatial inequalities can be of geographical areas. Social inequities economic, demographic, and geographic used to make assumptions about disaster allow for the increasing risk of biophysical factors, risk for loss (Cutter, 2003). In general, impacts. Susan Cutter developed a Social vulnerability especially in areas where the social science community is in consensus Vulnerability Index (SVI) which takes the inherent risk of natural disaster exposure is about key factors which influence social summation of indicators; personal wealth, high, and prejudiced social constructs can vulnerability. Those factors include; lack of age, density of the built environment, single- predisposition groups to damage. Social access to resources, limited access to political sector economic dependence, housing stock inequities construct the larger idea of power, social capital, building stock, and and tenancy, race, ethnicity and infrastructure social vulnerability, which are factors that age. When those factors are broken down to create an unweighted variable which 184 influence the susceptibility of groups to into measurable variables they equate to quantifies social vulnerability (Cutter, 2003). 185 Figure 3. Because of the spatial inequality of hazards, 2017). Classes are stratified not only by - Houston Concentrated social vulnerability indexes can be used socio-demographic characteristics, but Socioeconomic and demographic block disadvantage: Port to improve emergency management; by occupation. The working or industrial group level data for the Port of Houston of Rotterdam 2003 preparedness, response, planning, and class citizens, while they may be living was drawn from the Census American and 2010.. Source: recovery, by finding of vulnerable areas. Not above poverty level, are heavily reliant on Community Survey (U.S. Census Bureau, The Netherlands only can SoVI help to predict the outcomes infrastructure, and vulnerable to degradation 2017). The variables used include: age, Central Bureau of of disasters it can be used as a tool to from high use (Barrow, 2006). These income, race, gender, public assistance, and Statistics. evaluate recovery and resilience (Susan populations are also typically isolated by snap benefits for the year 2015. Raw data was L. Cutter, 2007). Where resiliency can be location, and do not tend to mix with those converted into percent for socio-economic defined as the ability of social systems outside their community. These populations and demographic variables After creating to absorb shocks, and rebuild so that the are typically ignored in U.S. social housing percent’s variables percent low income, community remains in the same functioning projects (Paul Watt, 2017). percent young (less than fifteen), percent state (Mayunga, 2007). Social resilience, old (over 65), percent nonwhite, percent which includes institutions for collective The Netherlands, as well as other European female, percent receiving public assistance, action, robust governance systems, and a countries, approach revitalization projects and percent receiving snap benefits were diversity of livelihood choices, are assets for differently than in the U.S. by taking a bottom used to quantify social vulnerability using the reducing the effects of natural hazards. up approach (Paul Watt, 2017). Taking not summation of variables z-scores. A variable only the poorest and most vulnerable into was created and labeled SV. This calculation Social mixing account, but the middle and industrial served as a simplified model of the more There has been a plethora of literature working class (Paul Watt, 2017). The last complex social vulnerability index described denouncing the effects of residential Revitalization project in the Netherlands in the literature review section. Another segregation and social isolation with began in 1997 and was implemented by variable was created based on the same many scholars addressing the negative demolishing old social or rental housing, in model, using the summation of variables “neighborhood effect” specifically the order to build more homeowner dwellings z- scores, and used variables; percent American ghettos (Gideon Bolt, 2010). By (Gideon Bolt, 2009). Social housing not white, percent female, percent young living in segregated neighborhoods residents corporations, aim to create equality in housing and percent old, and was labeled as CD are limited in their access to resources, ability tenure spatially at small neighborhood, or (concentrated disadvantage.) This was done to escape poverty, and job opportunities. This borough, levels by creating equal housing for for the years 2010 and 2015. The percent is specifically apparent for racial minorities all tenure, therefore deisolating vulnerable difference between 2010 and 2015 for CD was living in the inner city (Paul Watt, 2017). As populations (Sanders, 2017). calculated to represent the change between such there has been a lot of focus on social the years. The indexes, SV and CD, and mixing and revitalization policies, both urban In a personal interview with Dr. Fred C. percent differences were then georeferenced and rural, to combat these issues. Sanders former director of ZVH social- to the block group lines (2009) drawn housing company near Amsterdam, he from the Houston Galveston area council, Urban revitalization projects aim to de-cluster spoke of the equal distribution of housing encompassing a 5km space around the Port vulnerable areas, and mitigate place based tenure across the Netherlands helping to of Houston, to display the degrees of social Figure 4. social exclusion (Paul Watt, 2017). This aims create community initiatives, specifically vulnerability and concentrated disadvantage, Percent change to provide opportunity for underprivileged greening projects to help prevent flooding. and the changes between the two years in in concentrated people to gain social capital, political power With an equal distribution of middle class space (Houston-Galveston Area Council, disadvantage for and access to resources, by association with in neighborhoods there is more outreach 2009). 2003 and 2010. middle and upper-class populations. Paul and funding being collected for projects, Source: The Watt (17) stated in his book Social Housing specifically for the MAEX Citizens initiative - Rotterdam Netherlands Central and Urban Renewal: A Cross-National platform, which is an online community A similar process was done for port of Bureau of Statistics. Perspective that one of the leading causes initiative platform. These initiatives show how Rotterdam data. Social and demographic of urban poverty is the spatial concentration spatial heterogeneity can be an inference variables were drawn from the CBS of mono tenure estates. U.S. policy tends to of preparedness and resiliency within which included; age, gender, race, general commit to this idea, as seen in the case of communities (Sanders, 2017). assistance, and disability assistance for the HOPE IV programs, specifically cases in the year 2010 (The Netherlands Central Chicago where the new “projects” created Data Description and Methodology Bureau of Statistics , 2017). Raw data was led to systemic social isolation. This happens Data for this study came from various converted into percent for socio-economic because the policies in the US take a top sources including American Community and demographic variables After creating down approach and cater specifically to Survey of U.S. Census Bureau, Houston percent’s variables percent low income, the poor and racialized minorities, creating Galveston Area Council, and The Netherlands percent young (less than fifteen), percent old 186 a disconnect between classes (Paul Watt, Central Bureau of Statistics (CBS). (over 65), percent non-native, percent female, 187 Figure 5. of U.S. Census percent receiving disability assistance, and Results change in demographic variables is a strong Concentrated Bureau, Houston percent receiving general assistance were Results are presented as Figure 3-8 and begin inference for change in vulnerability across disadvantage: Galveston Area used to quantify social vulnerability, using the with the changes between years 2003 and the study area. Port of Houston Council. summation of variables z-scores. A variable 2010 for the Port of Rotterdam comparing 2010 and 2015. was created, CD, for both years 2003 and change in concentrated disadvantage, The results for the change in concentrated Source: American 2010 using the variables percent female, following revitalization policy (Figures 3 and disadvantage between the years 2015 and Community Survey percent non-native, percent young and 4, previous page). Results for the change in 2010 for the Port of Houston are presented in percent old, using the summation of variables concentrated disadvantage for the Houston Figures 5 and 6. There is an overall increase in z-scores. The percent difference between Port are then displayed for the years 2010 and CD for the study area of 33% (Table 2). 2003 and 2010 for CD was calculated to 2015 (Figures 5 and 6). Differences in Social represent the change between the years. vulnerability between the Port of Houston The results for Social vulnerability for the year and Port of Rotterdam are then displayed as 2010 for the Port of Rotterdam are presented The indexes, SV and CD, and percent (Figures 7 and 8, next page). in figure 5. The minimum score for a borough differences were then georeferenced to the group was -4.64 and the maximum being borough lines drawn from The Netherlands The results for the change in concentrated 9.237 with the average being .179 (Table 1). Central Bureau of Statistics, encompassing disadvantage between the years 2010 a five-kilometer space around the Port of and 2003 for the Port of Rotterdam are The results for Social vulnerability for the year Rotterdam, to display the degrees of social presented in Figures 3 and 4. In the years 2015 for the Port of Houston are presented vulnerability, concentrated disadvantage, and following revitalization there is an overall in figure 6. The minimum score for a block the changes between the two years in space decrease in CD for the study area of 39.7% group was -8.761 and the maximum being (The Netherlands Central Bureau of Statistics, (Table 1). While the formation of the variable 9.976 with the average being – 3.56e-07 2017). CD does not take income into account, the (Table 2).

Table 1. Summary Statistics: Port of Rotterdam Table 2. Summary Statistics: Port of Houston

Concentrated disadvantage 2003 Concentrated disadvantage 2010

Variable Obs Mean Std. Dev. Min Max Variable Obs Mean Std. Dev. Min Max cd03 168 -.3045007 1.082184 -1.866067 3.419215 cd03 249 1.01e-08 1.0825236 -5.93498 7.296106 Figure 6. Percent change in concentrated Concentrated disadvantage 2010 Concentrated disadvantage 2015 disadvantage for 2010 and 2015. Variable Obs Mean Std. Dev. Min Max Variable Obs Mean Std. Dev. Min Max Source: American cd 169 .1359912 1.030736 -2.289816 4.82376 cd 249 -3.06e-07 1.876889 -5.982924 5.062975 Community Survey of U.S. Census Bureau, Houston Percent Change in Concentrated disadvantage Percent Change in Concentrated disadvantage Galveston Area Council. Variable Obs Mean Std. Dev. Min Max Variable Obs Mean Std. Dev. Min Max pctchange 168 .-39.77926 661.6668 -3962.784 5359.506 pctchange 249 33.05071 2483.838 -8678.376 36914.31

Social Vulnerability 2010 Social Vulnerability 2015

Variable Obs Mean Std. Dev. Min Max Variable Obs Mean Std. Dev. Min Max 188 svi 169 .179383 2.614946 -4.641961 9.232732 svi 249 -3.56e-07 3.440881 -8.761339 9.976801 189 Figure 7. Discussion and Conclusion References Social vulnerability: Results for the change in concentrated Alice Fothergill, a. L. (2004). Poverty and Port of Rotterdam disadvantage for the Port of Rotterdam disaster in the United States. Natural Hazards, (2010). suggest that following a revitalization policy 89-110. Source: The there is a decrease in disadvantage. While Barrow, C. (2006). Environmental Netherlands Central Results for the Port of Houston suggest Management for Sustainable Development. Bureau of Statistics. that no policy or policies which promote New York : Routledge. isolation lead to an increase in CD. However, Barry E Flanagan, E. W. (2011). A Social the variable for concentrated disadvantage Vulnerability Index for Disaster Management. neglects income levels, because of limited Journal of Homeland Security and data for the Port of Rotterdam. The Emergency Management . variable for social vulnerability is a better Cutter, S. (2003). Social Vulnerability to representation of disadvantaged areas but Environmental. Social Science Quarterly , all component variables were not available 242-262. Gideon Bolt, D. P. (2010). Housing for comparison. Although the designation Policy, (De)segregation and social mixing: An of areas with high social vulnerability International Perspective . Housing Studies , allow policy makers to make changes and 129-136. distribute resources where necessary. Bolt, G., Van Kempen, R. and Van Weesep, J. (2009), After Urban Restructuring: Comparing the results of social vulnerability Relocations and Segregation in Dutch Cities. is in a way impetuous because of social, Houston-Galveston Area Council. (2009, political, and economic disparity, but allows July). Flood Management. Houston , TX . for the identification of helpful policy, Mayunga, J. S. (2007, July 28). Understanding regardless of its ability to be implemented and Applying the Concept of Community presently. Creating heterogeneity across Disaster Resilience. College Station , TX , housing tenure can improve social and United States . community capital, improving communities Paul Watt, P. S. (2017). Social Housing and access to resources, initiatives and political Urban Renwal: A Cross National Perspective . power, and overall resilience to a flooding Emerald Publishing Limited. Figure 8. event. In the wake of climate change and Sanders, D. F. (2017 , June 13). (E. F. Seong, Social vulnerability: the recent destruction caused by Hurricane Interviewer) Port of Houston Harvey to the Gulf coast and Houston Susan L. Cutter, a. C. (2007). Temporal and (2015). Metropolitan area the need for mitigation spatial changes in social vulnerability to Source: American policy is exceedingly necessary. Such as natural hazards. PNAS, 2301-2306. Community Survey vulnerability is not one dimensional the The Netherlands Central Bureau of Statistics . of U.S. Census mitigation efforts to decrease vulnerability (2017, June ). Dataportaal van de Nederlandse Bureau, Houston must be equally distributed in space and in overheid. Retrieved from https://data. Galveston Area discipline. overheid.nl/data/dataset/wijk-en-buurtkaart- Council. 2010-versie-3 U.S. Census Bureau. (2017, July). Harris County Block Group 2010 and 2015. Retrieved from Factfinder.census.gov: https://factfinder.census.gov/faces/nav/jsf/ pages/searchresults.xhtml?refresh=t W. Neil Adger, T. P. (2005). Social: Ecological Resilience to Coastal Disasters . Science , 1036-1039.

190 191 NSF-PIRE 2017 Case #3 COASTAL ENGINEERING WITH NATURE #3 O

SAND ENGINE AND NOORDWIJK

Image above: This case study focuses on vegetated coastal dunes in the context Here are some examples of Research Questions (RQ) that could (but Case study location. of natural and nature-based features (NNBF). NNBF have gained not must) serve as a guide: popularity in coastal engineering studies because they aim to provide Image to right: increased levels of protection against storm impacts (e.g., storm surge, RQ 1: How do pristine and engineered vegetated dunes differ between Sand Engine wave attack, wind forcing), while simultaneously maintaining and/or the Netherlands and the upper Texas coast; how are they being used along Dutch enhancing the coastal ecosystem and serving as aesthetic features in coastal protection schemes? coast at Kijkduin, within the coastal landscape. The use of NNBF has emerged as an RQ 2: What are the differences in meteorological forcing mechanisms Scheveningen. “Engineering with Nature” alternative or supplement to conventional impacting the Dutch and Texas coastlines, respectively; how does that Image Courtesy engineered solutions. influence the makeup, design, and effectiveness of vegetated coastal Rijkswaterstaat, dunes as NNBF? Beeldbank. Traditional approaches used to protect urban, commercial and RQ 3: How can NNBF best be implemented in numerical modeling industrial assets in coastal areas have included the construction approaches intended to simulate coastal geomorphology changes; of hardened structures such as storm surge barriers, seawalls, how do variations in coastal vegetated dunes between the revetments, groins and detached breakwaters. However, these Netherlands and Texas affect numerical model implementation? “conventional” engineering practices need to be implemented not RQ 4: (How) does Coastal Engineering with Nature in general and/or just with the primary protection function in mind, but also fit into the vegetated dunes specific, differ between The Netherlands and Texas; natural fabric of the coastal ecosystem to produce multiple benefits. how are NNBF in general and vegetated dunes specific incorporated Engineered dune systems are typical examples of this concept. in coastal planning and management? Comparing and contrasting pristine and engineered vegetated dune systems in the Netherlands with those along the upper Texas coast will help to better understand their protective functionality and value in coastal protection schemes. The intended locations for this project include dune systems at the Dutch Sand Motor near The Hague (engineered) and Noordwijk (natural) as well as Galveston (engineered) and Follets Island (natural).

Image to right: Noordwijk dike- in-dune coastal protection. Image courtesy Rijkswaterstaat Beeldbank, Harry van Reeken.

192 193 Figure 1. Andrew Whitley CEM is forced with offshore wave A NUMERICAL MODELING INVESTIGATION OF SPREADING TIME information. Modeled SCALES FOR A HYPOTHETICAL MEGA-NOURISHMENT wave fronts go through a linear wave FOLLET’S ISLAND , TEXAS transformation to obtain Andrew Whitley is currently a PhD-candidate spreading rates at Follet’s Island are conducive of a feature with a large cross-shore extent as breaking wave in oceanography at Texas A&M University. He to supplying sediment to nearby beaches on well as increasing overall beach surface area. information. holds degrees in physics, music, and marine annual time scales. This type of nourishment project has not yet Bathymetric science. been attempted on the Texas coast, but it is contours are Introduction expected that the Upper Texas Coast would assumed to be Recent efforts to provide a resilient benefit from all these advantages if a mega- straight and Abstract coastline for the Netherlands have taken a nourishment were implemented. parallel to the The Upper Texas Gulf Coast is coast pro-active philosophy to dune and beach mean coastline notorious for high erosive rates. In order reinforcement in addition to of the traditional The overarching goal of the study is to (x-axis). to adequately mitigate erosion in this area reactive approach of nourishing coastal explore the feasibility of mega- nourishment and to prevent flooding from storm surge, areas suffering from coastline retreat (van on Follet’s Island in the Upper Texas Coast by innovative solutions beyond the traditional Slobbe et al., 2013). Part of this pro-active numerically modeling a hypothetical mega- local nourishments must be explored. As a methodology is the introduction of an nourishment at that location. The viability of method of reducing nourishment costs for experimental mega-nourishment on the order a mega-nourishment at a specific location is coastal reinforcement, a mega-nourishment of 21.5 million m3 of sediment in a single dependent upon several site-specific criteria: on the Holland coast, the Delftland Sand location on the Dutch coast (van Slobbe (A) There must be morphodynamic Engine, has been constructed as a pilot et al., 2013; de Vries, 2014; de Schipper et significance for provision of additional project to test the feasibility of using large- al., 2016). This pilot project is known as the sediment into the area (i.e. an eroding coast). scale nourishments as feeder beaches for Delftland Sand Engine, and it aims to examine (B) The natural processes at the site must be adjacent shores. The benefits of such a the feasibility of a mega-nourishment in a able to adequately redistribute sediment to mega-nourishment would be highly desirable single location acting as a sediment feeder the nearby beaches. on the Texas coast where erosion rates and for a larger stretch of the coast. (C) The natural environment at the site must nourishment costs are high. In an effort to be able to endure a nourishment project determine the time scales necessary for Mega-nourishment is a relatively new without major damage. adjacent shores to experience accretive nourishment concept that relies on natural (D) There must be a supply of available effects from a mega- nourishment in the forces to disperse a large sediment volume sediment that has the appropriate qualities Upper Texas Gulf Coast, a hypothetical from single site. An effective mega- (grain size, etc.) for beach nourishment and mega-nourishment on Follet’s Island, Texas nourishment program acts as a feeder beach, whose transport does not make the project is numerically modeled using the Coastline providing a sediment source for beaches cost-prohibitive. Evolution Model (CEM). near the nourishment site. Advantages in (E) There must be the proper cultural such a mega-nourishment are outlined in the acceptability for the project in the region. Areas of the simulated shoreline a distance of goals of the Sand Engine project described ~3km away from the nourishment experienced in van Slobbe et al. (2013). The Sand Engine Criterion (A) has been evaluated in the 0.2m of accretion after ~1.45 years of model project aims to reduce construction costs study site selection process. With study time. After roughly 25 years of model time, the by nourishing a high sediment volume in at site selection complete, criterion (A) could

Breaking wave informa/on is used to calculate sediment flux (QS): nourished feature (a peninsula) had mostly single location as opposed to many smaller- be further explored to include the precise

5/2 Qs = K1 Hb cos(φb - θ) sin (φb - θ) diffused. Complete diffusion occurred after scale sites over several years. The project nourishment location. This level of specificity 40 years resulting in a near-straight coastline. should also result in a more natural coastal could be addressed at a later stage but Shoreline change over /me (∂s/∂t) occurs as a result of sediment flux

gradients (∂QS /∂x), assuming sediment is evenly distributed to depth D: As the Sand Engine was designed to be a profile in the long run as the coastal evolution lies outside the scope of this paper. By

∂σ/∂t = (-1/D)∂Qs/∂x 25-year long project, results of the modeled post-construction of the nourishment is exploring the natural forces contributing hypothetical mega-nourishment in Texas show primarily driven by natural processes. The to the geomorphological behavior, the σ = cross-shore shoreline posi.on φo = offshore wave angle QS = sediment flux θ = shoreline angle time scales of diffusion to be of roughly the peninsula created by the mega-nourishment primary focus of this paper is criterion (B). K1 = empirical constant x = alongshore posi.on same order as those expected for the Sand is intended to have ecological and In particular, this paper aims to determine Hb = breaking wave height t = .me 194 φb = breaking wave angle D = depth of shore face Engine on the Dutch coast. The modeled recreational benefits as well by the creation the temporal scale necessary for shores 195

Figure 2 adjacent to a hypothetical mega-nourishment providing protection for Christmas Bay, the Tropical cyclones are also significant wave period typically on the order of 5 to 6 PDF for Follets Island to experience accretive effects from the Brazoria National Wildlife Refuge, the Gulf forcings to Follet’s Island’s geomorphology s (Wijnberg, 2002; de Schipper et al., 2016). redistribution of sediment from the mega- Intercoastal Waterway, and a naval petroleum on short time scales (Carlin et al, 2015; Wave climate for the summer months tend 63% of waves nourishment. Adjacent shores in this case reserve (Harter and Figlus, 2016). Harter & Figlus, 2016). While wave-induced to be calm while energetic storms occur near approach from are defined as beaches a distance 2 to 3 km longshore sediment transport (LST) resulting the coast in both the autumn and winter the left away from the edge of the nourishment shore Follet’s Island is composed of a relatively from tropical weather is considered in the months (de Vries et al., 2014; de Schipper et feature (peninsula). thin (~1 to 4 m thick) accumulation of numerical modeling conducted in this study, al., 2016). Winter and autumn storms typically 28% of waves transgressive sands resting over top fluvial limitations in the model neglect cross-shore approach the coast from the southwest or approach at an Follet’s Island, Texas deposits from the Brazos River (Wallace et sediment transport processes. However, form the north, causing highly oblique angles oblique angle The site chosen to explore a hypothetical al., 2010; Carlin et al., 2015). The shoreface the model is designed to simulate shoreline of incidence for storm- generated waves (|phi| > 45o) mega-nourishment along the Upper Texas of the island is composed of fine sand while evolution on large time scales (usually longer approaching the coast and significant wave Gulf Coast is Follet’s Island. Follet’s Island overwash deposits dominate the lagoon side than a decade). Since shore sediment volume heights on the order of 4 m. Some of these is a natural barrier island located roughly of the island (Wallace et al., 2010). According lost during tropical events sometimes recover storms have a period of one year. The highest 81 km south of the Houston, TX city center. to Carlin et al. (2015), a series of shore- on time scales 4 – 5 years in the Upper Texas recorded wave heights occur September to Follet’s Island is adjacent to Galveston Island, parallel sand bars are present, spanning from Coast (Morton et al., 1994), it is assumed December. which contains the city of Galveston, TX, a the toe of the fore-beach to a water depth of that any effects from cross-shore processes major tourist center for the region. Follet’s approximately 3 m. during tropical events and their recovery The design of the Delfland Sand Engine Figure 3. Island is mostly undeveloped containing periods cancel out. Some sediment volume was based on extensive morphodynamic Topographic only a small community (Surfside Beach) Previous studies have reported that Follet’s loss from cross-shore sediment transport modeling (Mulder and Tonnon, 2011). parameters on the southwest side of the island. Follet’s Island is eroding with shoreline change rates over several decades is expected in a physical Morphodynamic evolution of the mega- (bathymetric slope Island and Galveston Island are both actively ranging from stable to –3 m/yr and bay system, but exploring this is outside the nourishment was modeled on an time & shore face depth) eroding (Wallace et al., 2010; Carlin et al., line change rates varying from stable to +1 scope of this paper. scale of 20 to 50 years using the Delft3D for CEM are similar 2015), making Follet’s Island an acceptable m/yr (Wilkinson and Basse, 1978; Wallace model (Lesser et al., 2004) coupled with to those found at nourishment site according to criterion (A). A et al., 2010; Carlin et al., 2015; Harter and The Delfland Sand Engine SWAN (Holthuisen, 1993) to handle wave Follet’s Island. mega-nourishment on the center of the island Figlus, 2016). Wallace et al. (2010) describe The coast of the Holland, on which the transformations (from offshore to nearshore) would be over 5 km away from Surfside the island in a “rollover phase” with the Delfland Sand Engine was constructed, and TRANSPOR2004 (van Rijn, 2007a; Beach. This is considered far enough away to rate of shoreline retreat equal to the rate is characterized as a sandy, inlet-free, 2007b; 2007c) to handle sediment transport. not disturb its population but close enough of landward bay line movement. The island microtidal (a mean tidal range of 1.7 m), A dune model was also used developed by e Figure 4. that the added sediment volume could is also currently in a state of sediment wave- dominated coastline (Wijnberg, Vriend and Roelvink in 1989 (see Mulder and Coastline Evolution be used for recreation. Such a placement starvation. The Brazos River, once a major 2002; de Schipper et al., 2016). The overall Tonnon, 2011 for details) that was based on location would also be less than 13 km away sediment source of the island, was rerouted coastline (prior to the mega-nourishment) historical data. Model calculations showed from Galveston Island, theoretically making it 10.5 km west of Freeport jetties in 1929 and has a concave shape that is oriented north- that long term (20 – 50 yrs) morphological close enough to feed the Galveston beaches. later dammed, resulting in a loss of fluvial northeast to south-southwest (Wijnberg, effects of different sand engine design These factors make the site acceptable sediments once supplying the barrier island 2002). The beach and dune substrate in the alternatives are similar. A Hook- type shape according to criterion (E). (Harter and Figlus, 2016). Sand Engine region prior to its construction (Fig. 2) was the preferred alternative as this is mainly sand with a mean grain size of would create inter-tidal habitats and should Follet’s Island is a thin transgressive barrier Offshore wave climate information for the 250 microns (de Schipper et al., 2016). The double the rate of dune area increase. island located on the Upper Texas Gulf Follet’s Island region is obtained from the shore of the Holland coast faces the shallow Coast with a back-barrier lagoon (Wallace NOAA-NDBC Station 42019 wave buoy, North Sea Basin, which is roughly 20 – 80 m The Sand Engine was constructed with et al., 2010; Carlin et al, 2015). The island has located roughly 111 km south of Freeport, TX. in depth (de Schipper et al., 2016). Offshore sediment dredged from 5 to 10 km offshore, relatively low elevation, is generally less than Station data from 1990 – 2014 show a mean waves generally approach the coast from the totaling a 21 million m3 volume used in the 1 km wide in most areas, and is roughly 23 km significant wave height (Hs) of 1.25 m with a southwest or from the northwest (Wijnberg, project (de Schipper et al., 2016). 17 million in length (Fig. 1). The island is bounded by the peak Hs of 6.31 m. The mean wave period for 2002). Swell generated on the Atlantic m3 of sediment was used in the hook-like Gulf of Mexico on the shore-side, Christmas this data set is 4.76 s. The majority of waves Ocean of the northern North Sea approach peninsula. The average grain size of these Bay and the Gulf Coast Intracoastal Water approach the coast from the southeast in the Dutch coast from the north due to the sediments (D50) during nourishment was Way (GIWW) on the bayside, the San this region with longshore drift along the geometry of the basin (Wijnberg, 2002). 281 microns. Upon completion, the nourished Luis Pass tidal inlet to the northeast, and Follet’s Island shore predominantly northeast The average shoreface slope along the peninsula had its most seaward position the Freeport navigational channel to the to southwest (Morton et al., 1994; Carlin et al., Holland coast varies between 1:140 and 1:450 approximately 1 km from the original southwest. San Luis Pass is a mostly natural 2015). Variations in seasonal wind patterns (Wijnberg, 2002; de Schipper et al., 2016). shoreline. Cross-shore slope of the formation tidal inlet with both a prominent flood- and and shoreline orientation cause the littoral was 1:50 with the toe of nourishment at –8 m ebb-tidal delta (Israel et al., 1987), while the drift to reverse periodically (Morton et al., The offshore wave climate for the Dutch (vertically) and +1500 m (cross-shore) from Freeport navigational channel has been 1994). An in-depth analysis of the Follet’s coast has seasonal differences in wave the original shoreline. It also contained a small dredged and reinforced with jetties (USACE, Island offshore wave climate is discussed in forcings (de Schipper et al., 2016). The annual lake at the base to prevent seaward migration 196 2012). The island acts as a natural barrier the methods section. mean wave height for the region is 1.3 m with of the freshwater lens in dunes. Construction 197 Figure 5 Figure 6 of the mega-nourishment took place from off Follet’s Island) is used in the PDF (Figure 2, the image such that every pixel represents a the center area (feature tip) is eroding overall Nourishment half- Time for min. March 2011 to July 2011. previous page). 1 m x 1 m square, and shoreline coordinates and the lateral boundaries are accreting. life: ~6.15 years accretion (0.2 m): are taken along the 0-m NAD isobath every Accretion does occur just right (northeast) ~1.45 years Following its construction, the Sand Engine The initial coastline in CEM is designed 100 m in the alongshore direction. This of the feature tip from 2.06 – 2.41 years and Time for max. exhibited a rapid redistribution of sediment, to have a coastline similar in shape to the resolution is chosen to be comparable to the from 2.41 – 3.38 years, which accounts for the accretion (148.7 m): mostly in the alongshore directions (de Sand Engine (for comparison). To prevent CEM output resolution. The coastline position rightward migration of the feature tip visible in ~35 years Vries et al., 2014; de Schipper et al., 2016). numerical errors with lagoons, a coastline for every profile is shown in Figure 12b. For the 2.41-year and 3.38-year profiles. Otherwise, Erosion on the Sand Engine peninsula very similar in shape to the Feb. 2013 profile comparison, the coastline position of the erosion of the feature tip is fairly persistent. was considerable while depositions on the of the Sand Engine is used. This coastline has model output is shown in Figure 12a at model beaches adjacent to the feature were of no lagoons and is slightly diffused from it’s times comparable to the evolution of the In general, the periphery of the feature itself similar magnitude (de Vries et al., 2014). This original hook shape (Figure 3, previous page). Sand Engine. An alongshore extent for the along with the adjacent areas experience is indicative of diffusion of the peninsula CEM coastlines shown is chosen so that initial accretion. A notable exception is the 2.06 due to longshore sediment transport. Results coastline of the hypothetical Follet’s Island – 2.41-year time interval where erosion is There are also seasonal differences in the (This is a short summary of the research mega-nourishment is similar in size, shape, consistent on both sides. The 1.00 – 1.35-year geomorphic behavior with large changes in results, for full text, calculations and model and position to the Sand Engine coastline time interval does show erosion on the left sediment volume occurring during months outcomes please contact the author) dated February 17, 2013. side of the feature, but it is accompanied by characterized by strong wave conditions significant accretion on the right side. The (December – February) and relatively little Coast line evolution: When forced with a wave The Sand Engine coastline geomorphology 2.41 – 3.38-year interval signal also shows geomorphology during periods experiencing climate similar to Follet’s Island, the mega- shows continual retreat of the feature tip with a low order of erosion on the right side, mild wave conditions (July – August) (de nourishment diffuses. This occurs rapidly at accretion on the lateral boundaries of the but it is also accompanied by accretion on Vries et al., 2014). Considering volumetric first, but then slows. Complete diffusion takes nourishment. Erosion is present throughout the left. Furthermore, the right side of the changes during stormy months are on the several decades and results in a near-straight the feature tip but appears to be stronger feature typically shows accretion signals of same order as those spanning an entire year coastline (Figure 4, previous page). on the left (southwest) side of the feature. greater order than the left. An exception to (de Vries et al., 2014), wave action due to Accretion is also present on both sides of this would be the time interval of 0.38 – 1.00 meteorological forcings are likely a significant Time scales: The nourished region (x = 3.0 to the nourishment, though there is significantly years, though both sides show significant driver in the Sand Engine’s geomorphology. 6.6 km) loses sediment volume rapidly. Half more accretion on the right (northeast) side accretion during this period. The accretion of the sediment volume has been transported than the left. The rate of tip erosion does signals of greatest magnitude appear during Figure 7. Methods out within 6.15 years (Figure 5). not appear to be constant as the cross- the 0.00 – 0.38-year and 1.00 – 1.35-year the Differing wave (This is a short summary of methods used,, Time for areas ~ 3 km away from the shore extent of the feature remains largely intervals, the latter being slightly larger. climates are likely a for full text, please contact the author) nourishment to experience the following unchanged for the shorelines of 1.35, 2.06, contributing factor The Coastline Evolution Model (CEM) is used amounts of cross-shore extension due to and 2.41 years after the initial coast. A comparison of the evolution of shorelines to this difference. to explore change in cross-shore shoreline nourished sediment distribution (Figure 6). of the Follet’s Island mega- nourishment Below show the position(s) over large time scales and spatial De Vries et al. (2014) report a temporal simulation and the Sand Engine are visible wave offshore wave scales. It uses a cellular grid to represent the It is important to note that throughout correlation between significant longshore in Figure 12. The model coastlines tend to be climates of the two land, beach, and water. Each cell numerically the simulation, the left (northeast) side of transport volumes in the Sand Engine and very smooth while the Sand Engine coastlines regions (shoreline represents the fractional amount of surface the feature accretes more rapidly than the seasonal forcing conditions. They state that are rather jagged. The former is likely the indicated by a gray sediment (0 = water; 1 = land; other = beach). right (southwest) when examining an equal transport is the greatest during the stormy result of the model’s tendency to smooth out line). (Figure 1, first page) distance to the edge of the feature. This is months (Dec. 2013 through Feb. 2014) with coastlines, particularly with low highness in likely due to the buildup of sediment resulting relatively little transport during the calm wave climate (U < 0.5). The latter could be CEM is forced with offshore wave information. from the dominant rightward transport in the months (July 2013 through Aug. 2013). They due to signal noise in the transformation from Modeled wave fronts go through a linear model domain accompanied by changes in also state that the transport magnitudes topographic image to single-line coast, which wave transformation to obtain breaking alongshore sediment gradients resulting from during the stormy months are on the same is accentuated by the fact that a relatively wave information. Bathymetric contours are the center feature. order as those for a full year (Feb./Mar. 2012 low resolution is being used (1 shoreline point assumed to be straight and parallel to the through Feb./Mar. 2013). It is expected to find every 100 m alongshore). mean coastline (x-axis). Model Comparison with the Sand Engine a correlation between coastline changes and In order to compare the CEM results with stormy versus calm seasons with the data In terms of shoreline evolution, the both the The offshore wave climate (forcing) is those of a physical mega-nourishment, sets presented here. However, no correlation Follet’s Island model and Sand Engine exhibit represented using a Probability Distribution the Delftland Sand Engine, the between could be found considering that all feature diffusion, though this occurs much Function (PDF) that simulates the probability geomorphological change in the Sand of the time intervals between topographic more rapidly in the model. The model also of any wave approaching the coast with a Engine coastline is considered. Images of profiles contained both stormy and calm tends to spread sediment out more evenly, particular incident angle (phi). The amount of topographic profiles of the Sand Engine months (see Table 1). reliably having accretion on both sides of wave energy contributing to total sediment provided by TU Delft are examined for the feature and having no accretion at the flux approaching the coast (averaged over 24 the dates shown in Table 1. A coastline is An examination of the coastline change signal feature tip. The Sand Engine coastline does 198 years of data from NOAA-NDBC Buoy 42019 extracted from each image by re- projecting for the Sand Engine (Fig. 14b) confirms that not diffuse evenly, favoring accretion on 199 Figure 8. the right side of the feature. Furthermore, outgoing if wave breaking conditions and providing the Follet’s Island wave rose. I Mulder, J. P., & Tonnon, P. K. (2011). “Sand Follet’s Island Wave the Sand Engine, on occasion, does show shoreline angle are the same on either side of thank Timothy Dellapenna for reviewing the Engine”: Background and design of a mega- Climate (Courtesy of accretion at the tip, such as the 2.06 – 2.41- the domain. paper. I also send thanks to Jens Figlus for nourishment pilot in the Netherlands. Coastal Craig Harter) year time interval. The erosion/accretion - The offshore wave climate is simplified. his guidance throughout the project. This Engineering Proceedings, 1(32), 35. signals (Fig. 15) for CEM and the Sand Engine A higher-resolution wave climate can be research was supported by the National USACE [U.S. Army Corps of Engineers] show the same pattern overall with erosion at examined in future work. Science Foundation under Grant No. OISE- (2012). Freeport Harbor, Texas: Channel the feature tip and accretion on sides of the - A CEM simulation for the Sand Engine was 1545837. Improvement Project Feasibility Report. feature. This accretion is more prevalent on not run for comparison due to project time Volume 1. the right side in both the model and the Sand limitations. This is planned in future work. van Rijn, L.C.( 2007a). United view of Engine, though the disparity is more extreme The presence of inlets near the mega- References sediment transport by currents and waves (Shore) in the Sand Engine case. nourishment may inhibit feeding sediment to Carlin, J., Figlus, J., Dellapenna, T., & Harter, I: Initiation of motion, Bed roughness and nearby beaches. C. (2015). Investigating morphological and Bed load transport. Journal of Hydraulic Discussion stratigraphic changes to the submarine Engineering, ASCE, Vol. 133, No. 6, p.649-667. (This is a summary; for full discussion and Conclusions shoreface of a transgressive barrier island: van Rijn, L.C.( 2007b). United view of conclusions please contact the author) - The Follet’s Island model diffuses faster Follets Island, northern Gulf of Mexico. sediment transport by currents and waves In comparison with the Sand Engine, the than the Sand engine because it’s wave Coastal Sediments: The Proceedings of the II: Suspended transport. Journal of Hydraulic Follet’s Island model diffuses much faster and climate is less oblique (on average). Coastal Sediments. Engineering, ASCE, Vol. 133, No. 6, p. 668-689. more evenly than the observed Sand Engine - The Follet’s Island model diffuses more de Schipper, M. A., de Vries, S., Ruessink, G., van Rijn, L.C.( 2007c). United view of diffusion. Figure 7 (previous page) shows symmetrically than the Sand Engine de Zeeuw, R. C., Rutten, J., van Gelder- Maas, sediment transport by currents and waves the first few years of evolution for both the because it’s wave climate is more C., & Stive, M. J. F. (2016). Initial spreading of III: Graded Beds. Journal of Hydraulic Follet’s Island model and the Sand Engine symmetrical. a mega feeder nourishment: Observations Engineering, ASCE, Vol. 133, No. 7, p. 761- 775. (after Feb. 2013). Differing wave climates are - Model results show that shores ~3 km of the Sand Engine pilot project. Coastal van Slobbe, E., de Vriend, H. J., Aarninkhof, likely a contributing factor to this difference. away from the mega-nourishment Engineering, 111, 23–38. https://doi. S., Lulofs, K., de Vries, M., & Dircke, P. (2013). Below show the wave offshore wave climates experience accretive effects less than org/10.1016/j.coastaleng.2015.10.011. Building with Nature: in search of resilient of the two regions (shoreline indicated by a 2.5 years after the mega-nourishment’s de Vries, S., de Schipper, M. A., & Stive, M. storm surge protection strategies. Natural Figure 9. gray line). completion. (2014). Measured gradients in alongshore Hazards, 66(3), 1461–1480. https://doi. Sand Engine Wave - Model results show that the time order for sediment transport along the Dutch coast. org/10.1007/s11069-013- 0612-3. Climate (Courtesy The wave climate in the Sand Engine has total diffusion of the feature is about Coastal Engineering Proceedings, 1(34), 58. Wallace, D. J., Anderson, J. B., & Fernández, R. of de Schipper et al., much more wave energy approaching from 24 – 32 years. Harter, C., & Figlus, J. (2017). Numerical A. (2010). Transgressive Ravinement versus 2016) oblique angles than that in Texas (Figures - The model shows ~149 m of cross-shore modeling of the morphodynamic response of Depth of Closure: A Geological Perspective 8 and 9). Oblique wave angles can cause coastline extension resulting from the a low-lying barrier island beach and foredune from the Upper Texas Coast. Journal of shoreline instabilities that slow diffusion or mega-nourishment. system inundated during Hurricane Ike using Coastal Research, 26, 1057–1067. https://doi. can cause anti-diffusion (Ashton and Murray, - Modeled spreading (diffusion) rates for a XBeach and CSHORE. Coastal Engineering, org/10.2112/JCOASTRES-D-10-00034.1. 2006). The Follet’s Island wave climate hypothetical mega-nourishment on Follet’s 120, 64–74. https://doi.org/10.1016/j. Wilkinson, B. H., & Basse, R. A. (1978). Late has relatively few oblique angled waves, Island are conducive to supplying sediment coastaleng.2016.11.005. Holocene history of the central Texas coast increasing shoreline diffusivity. Follet’s Island to nearby beaches on annual time scales. Holthuijsen, L. H., Booij, N., & Ris, R. C. (1993, from Galveston Island to Pass Cavallo. (Shore) also has a more symmetric wave climate July). A spectral wave model for the coastal Geological Society of America Bulletin, leading to more even spreading. zone. In Ocean Wave Measurement and 89(10), 1592–1600. Acknowledgments Analysis: (pp. 630-641). ASCE. Wijnberg, K. M. (2002). Environmental Study Limitations I would like to thank Bruce Ebersole and Israel, A. M., Ethridge, F. G., & Estes, E. L. controls on decadal morphologic behaviour - The model assumes that bathymetric Wesley Highfield for their help with the (1987). A sedimentologic description of a of the Holland coast. Marine Geology, 189(3– contours are straight and parallel with the background theory and research approach. I microtidal, flood-tidal delta, San Luis Pass, 4), 227–247. https://doi.org/10.1016/S0025- mean coastline. would also like to thank Matthieu de Schipper, Texas. Journal of Sedimentary Research, 3227(02)00480-2. Alongshore variations in physical bathymetric Sierd de Vries, and Kathelijne Wijnberg for 57(2). contours are slight and may not be captured their helpful discussions through the course Lesser, G. R., Roelvink, J. A., van Kester, J. A. in the model’s resolution (100 m cell width). of this research. I send thanks to Samuel T. M., & Stelling, G. S. (2004). Development - The model assumes that longshore Brody, Baukje Kothuis, and Yoonjeong Lee and validation of a three-dimensional processes are only contributing factors to for their support in managing the NSF PIRE morphological model. Coastal Engineering, shoreline change. Sediment lost offshore from Coastal Flood Reduction Risk Program. I 51(8–9), 883–915. https://doi.org/10.1016/j. cross-shore processes during a hurricane would also like to thank Connie Do, Deidra coastaleng.2004.07.014. may recover on long time scales (Morton et Dittmar, and Bella Jezierski for working with Morton, R. A., Paine, J. G., & Gibeaut, J. C. al., 1994). me on the Coastal Engineering with Nature (1994). Stages and durations of post-storm - The model assumes that sediment is Team and for help with the introduction beach recovery, southeastern Texas coast, 200 conserved. Incoming sediment may replace to this paper. Thanks to Craig Harter for USA. Journal of Coastal Research, 884– 908. 201 Figure 1. Deirdra Dittmar Location difference. Made with ESRI ArcMap. Sources: MULTIFUNCTIONALITY OF AN ENGINEERED COASTAL ESRI, DeLorme, HERE, MapmyIndia. PROTECTION STRUCTURE

CASE STUDY OF A COASTAL MEGA-NOURISHMENT: THE SAND ENGINE

Deidra is an undergraduate student studying project along its southern coast, which is coast is eroding, 33% is in equilibrium, and Offshore and Coastal Systems Engineering at host to many multi-functional components. 6% is experiencing accretion (USACE, 1993). Texas A&M University at Galveston. The goal of this study is to examine A major threat to the Texas coastline comes the multifunctional aspects of a mega- from intense coastal storms such as tropical nourishment and understand its potential if storms or hurricanes. The frequency and Coastal shorelines across the world are a similar engineered structure was placed intensity of these storms varies each year significantly more populated than other along the Texas Gulf Coast. It is expected that though, they typically occur between the inland areas. As of 2007, 40% of the the Netherlands and Texas will have many months of June and November. According to worldwide population lives within 100 km multifunctional aspects, with many positive the National Weather Service, every 50 miles from the coast (UN, 2007). In the United and negative outcomes. Both places may of Texas coastline is expected to be struck by States, counties located along the shoreline also share a commonality or difference due a hurricane every six year (Scranton, 2016). have population densities of around six to their large variance in location, as seen in times larger than the population of an inland Figure 1. Engineering with Nature county. In 2010, it was found that 39% of the Protection to coastal and flood prone areas United States population was living directly Netherlands Coast can be maintained by many engineering on coastal shorelines. The populations in The Netherlands is protected by a methods. Originally various “hard these regions are still rising and are expected highly modified sandy coastline that is engineering” structures were designed to increase by approximately 8% by the year approximately 120 km in length. The coast and built throughout the Netherlands. Figure 2. 2020 (NOAA, 2016). In similar comparison, is exposed to the North Sea, from which This included the introduction of dams, Sand Engine the country of the Netherlands is about 30% arise intense northwesterly storms, that storm surge barriers, dikes, and other (Made with ESRI under sea level (Sistermans and Nieuwenhuis, can produce storm surges up to 4 meters reinforcements. Similar hard structures, ArcMap. Sources: 2004). The Netherlands is the most densely above the mean sea level. Furthermore, the such as the Galveston Sea Wall, can be seen Esri, DigitalGlobe, populated European country, with 55% of Netherlands has experienced an overall sea along the Texas coast as well. While these GeoEye, i-cubed, the country located in flood prone areas level rise of around 20 cm within the last structures have presented some protection Earthstar (Giardino et al., 2011). Populations are rising century. Many areas are also being threatened to the area, they have more recently been Geographics, across the world and at even higher rates by subsidence, which in some places is a challenged for their effectiveness. Many CNES/Airbus near the coast. In order to protect coastal greater threat than the sea level rise (van engineered protection projects also come DS, USDA, USGS, infrastructure with increasing flood threats, Slobbe et al., 2013). With sea levels continuing with unforeseen effects on the surrounding AEX, Getmapping, new precautions must be taken. to rise and a third of the country under sea area. Recently it has been proposed that hard Aerogrid, IGN, IGP, level, flood protection is of highest priority to engineering structures may in the long run swisstopo, and the Coastal protection is extremely important the people of the Netherlands. increase the vulnerability to protect societies GIS User Community and is enforced among coastlines across (van Slobbe et al., 2013). the world including that of the Netherlands Texas Coast and Texas. Coastlines are a first line defense The Texas Gulf coastline is approximately A solution for a less invasive, and effective system against storm surge, flooding, and 590 km long and is mostly protected by coastal protection system comes from erosion. Recently due to increasing sea-level a formation of narrow barrier islands and the idea of “soft engineering”. The soft rise, magnitude and frequency of storms, peninsulas. The region between the barrier engineering technique was originally formed and the importance of protecting local islands and mainland is encompassed by with growing concerns for the environment. populations, there has been a profound intertwining shallow lagoons and bays, Known as “Engineering with Nature”, man- pressure to not only protect coastal areas, which are occasionally in contact with made designs are meant to integrate a but provide multi-functional opportunities inlets. The shore face of the Texas coast is natural appearance, while incorporating a (A.V. de Groot el al., 2012, de Schipper et commonly protected by natural or man- more resilient and multi-functional coastal al., 2016). Recently, the Netherlands has made structures such as dunes, sandbars, protection system (van Slobbe et al., 2013). 202 implemented a mega-nourishment pilot and seawalls. Overall, 60% of the Texas Gulf One method that presents engineering with 203 Figure 3. nature and that is practiced along both areas larger nourishments were necessary, page (de Schipper et al., 2016). A small lake Beach entrance to the Dutch and Texas coastline is beach which required between 400-600 m3/m of of about 0.08 km2 was placed at the base the Sand Engine nourishment. additional sand (de Schipper et al., 2016). of the peninsula, and a small lagoon was and bicycle & Nourishment projects are systems with a placed at the inner portion of the hook (de foot path through Beach Nourishment: finite life, which require re-nourishment Schipper et al., 2016., van Slobbe et al., 2013). adjacent dunes Beaches provide protection to the shore and to maintain design integrity (NRC, 1995). While many of the designs tested could have (Image courtesy hinterland from coastal storms. The amount The amount of time allotted before re- been suitable solutions to obtain the desired Rijkswaterstaat of protection provided by the beach depends nourishment is needed depends on the outcomes, the hook design was ultimately beeldbank) on the volume of sand, coastline shape and erosion and accretion rates for each location. chosen as it was expected to provide the orientation, location, and the properties In some locations, nourishment may be most useful multifunctional proponents (de of local wave impacts. Even without the needed every 3 to 10 years. Recently, a Schipper et al., 2016). presence of a major coastal storm, coastlines new nourishment paradigm has come into continue to naturally erode from wave and practice, which could be applied to coastlines The Sand Engine is expected to current action. Erosion not only negatively that experience high annual sand loss. morphologically change at a rate of a few affects coasts by making the region more This idea uses a large-scale nourishment hundred meters each year. The overall prone to damages from storms, but it also that naturally distributes through wave process for the mass to fully dissipate endangers the multi-functional components and current action to replenish both the along the shoreline is estimated to take of the area (NRC, 1995). Without the application site and areas further alongshore. approximately 20 years (van Slobbe et presence of a flourishing beach, many shore- This innovative concept was established in al., 2013). Since the Sand Engine has been side business endeavors, and beach-going 2011 as a pilot project in the Netherlands implemented its morphological changes recreation would not be possible. To protect known as the Sand Engine (de Schipper et al., have been occurring as expected. There have the coast, beach nourishment projects are 2016). been many multi-functional results due to the implemented as a technique to widen the Sand Engine design and morphology. Many beach (de Schipper et al., 2016). Recently, as The Sand Engine of these aspects have been positive, while increasing pressures on coastal protection The Sand Engine is a mega-nourishment there have also been some negative and has been recognized as a necessity, the originally implemented in the Netherlands as unforeseen repercussions. number of nourishment projects across the an experimental project to present a large- world has increased, specifically in Texas and scale solution to coastal beach replenishment. Mega-nourishment Multi-functionality the Netherlands. The intent was that by applying an extensive - Recreation volume of sand to one area, the cost of a Beaches are a highly valued area of Nourishments are a common practice single mega-nourishment project would be recreation for visitors, residents, and along United States as well, with over 200 less than multiple small nourishments. The commercial activities. A major multi- nourishment sites since 1920. The volume of project was also meant to produce many functional aspect when choosing the location sand used in these areas were in the range multi-functional outcomes, which would be of the mega-nourishment in the Netherlands of 150 m3/m to 600 m3/m initially. Along beneficial to the surrounding area. In all, the was based on the need for an attractive and the Texas coastline nourishments were at project was meant to gain knowledge over recreational beach (van Slobbe et al., 2013). first on a small scale; however, nourishments the impacts of a mega-nourishment along a The coast of the Netherlands experiences have recently grown in volume. Of 60 coastline, and give insight for future projects the highest erosion rates along its northern nourishment areas in Texas, about 65% of (van Slobbe et al., 2013). coastal region. However, the Sand Engine was these nourishments typically require around placed along the southern coast (Sistermans 200,000 m3 of sand. These projects intend to The Sand engine was constructed from 21 and Nieuwenhuis, 2004). The Sand Engine supply sand to beaches and dunes through million m3 of dredged sand material, which was placed in a popular urbanized area the use of dredged material (Campbell and when placed on the shore increased the known as The Hague, which is the third Benedet, 2004). More recently there has originally 150 m wide beach to 1500 m (de largest city in the Netherlands (Misachi, 2016). been thought as to how a mega-nourishment Schipper et al., 2016). There were multiple The aim of placing the nourishment in this would impact the Texas coast, especially locations and designs proposed for the Sand location was to increase living quality of the along the Galveston area. Engine. These ideas ranged from attached area, while not posing a threat to a coastline shore face sand bars, bells, peninsulas, that experiences dangerously high coastal Nourishment projects in the Netherlands hooks, and detached islands (Mulder, 2011). erosion, such as that seen in the northern implemented before the 1970’s were The final design selected was in the shape coast. distributed based on weak link locations of a large hook, with the tip of the hook along the shoreline. These nourishments extending toward the north. The design also The design chosen for the Sand Engine were placed on a small scale of about 100 included two very unique features, a lake incorporated both a lake and lagoon 204 m3 of sand per meter alongshore. For some and lagoon, as seen in Figure 2, prebious addition. The purpose of having these 205 Figure 4. two features was to provide unique - Environment Aspects and sand availability (Leatherman, 1989). Recreational use recreational opportunities that are not Environmental growth was a driving factor While sand is relatively cheap and heavily of Sand Engine usually found in a beach location. These in the design and planning process of the available in the Netherlands, the case in (Image courtesy locations allowed beach goers to enjoy an Sand Engine. The original expectation Texas is much different. In 2011 when the Rijkswaterstaat alternative swimming location that were for the lagoon feature was to create a Sand Engine was built, the regular cost of beeldbank) more limited and shallow compared to temporary habitat for wildlife, which may sand without any discount rate was priced the ocean (van Slobbe et al., 2013). One be uncommonly seen for a beach habitat at €6/m3 or $5.14/yr3 (van Slobbe et al., unplanned recreational surprise that erupted (van Slobbe et al., 2013). Soon after the 2013). In comparison, a beach nourishment with popularity after the Sand Engine was construction of the mega-nourishment was performed in 2015 along the Galveston coast completed was the number of kite surfers completed, there was a vast array of wildlife required 118,000 yr3 of sand at a cost of $38/ flocking to the area. The most popular area developing in the new territory. These forms yr3 (Rozier, 2017). This great variance in cost for the kite surfers was the lagoon site, since of ecology included an increased number makes a mega-nourishment less economically it was almost entirely blocked off from the of birds, fish, and pioneer vegetation (igure feasible along the Texas coast. Although sand beach and had perfect conditions for the 5 next page). There were also some very is more expensive in Texas, nourishments are sport (van Slobbe et al., 2013). Kite surfing is unusual species that made home to the area, still a necessity. While a mega-nourishment a popular sport along the Texas coast as well. which were occasional basking seals and a may cost significantly more initially, it could If a mega-nourishment were to be placed rare plant known as Atriplex laciniata (van save money in the long-run compared to that along the Texas coast, a similar effect could Slobbe et al., 2013). Many of these species of many smaller-scale nourishments over be seen with a rising interest of people in a may not have accompanied the area if the long periods of time. new kite surfing location. Sand Engine had not been placed. While the exact species of wildlife seen on the mega- - Safety Considerations The Sand Engine as a whole has created new nourishment in the Netherlands is not likely While the Sand Engine has the intent to recreational opportunities for swimming, to be seen in such a different climate as that provide extended coastal protection, there surfing, walking, or a leisure dog walk along in Texas, other types of ecology would likely have been some safety hazards involved. the Holland coast. These benefits could also occur. Since the Sand Engine was created, there be experienced along the Texas coast if a have been several occasions during which mega-nourishment were to be implemented. - Economics people have encountered dangerous The Texas coastlines are prominent Tourism and travel is a valuable industry situations. Unlike a typically straight recreational, fishing, and vacationing hotspot within the United States, and it is also a large and uniform beach, the unusual shape (USACE, 1993). Galveston, Texas, as one source of job opportunity. In the states it presented by the mega-nourishment caused example, is already a prominent area for was found that 40% of people find beaches interactions with tides and currents that local swimming, surfing, paddle boarding, and kite to be their most favorable destination for and visiting people were not accustomed surfing. An increased sand surface area would vacationing. From this it was found that 85% (Stive et al., 2013). expand coastal recreation opportunities for of the revenue that comes from tourism is this or other locations. A mega-nourishment spent in coastal states, such as Texas (NRC, The Sand Engine is a dynamic beach with a in the Galveston region could increase 1995). Tourism is also a major factor in the constantly changing lagoon feature. During beach attraction by permitting both a large Netherlands. The Holland coast is one of the the transition period between high and quantity of sand and increased parking most valued tourist destinations with 30% low tides, the lagoon rapidly fills or drains areas. Currently in Galveston, parking is only of the time allotted by holiday vacations water through its small cannel on the north permitted on a few beaches and along the filled with time at the beach (Sistermans and side. The velocity at which water enters sea wall. Providing a mega-nourishment Nieuwenhuis, 2004). Besides tourism, coasts the lagoon is similar to that of a powerful could yield higher volumes of people as are an extremely valuable source of income rip current (Stive et al., 2013). With water they come to enjoy the recreational benefits. from the surrounding ports. Over 65% of the velocities recorded to be over 1 m/s, many However, notice would have to be given to gross national product within the Netherlands beach goers, swimmers, and lifeguards were visitors about the location of their parked car comes from the coastal regions. With not expecting such drastic changes, and in and the potential changes between high and numerous ports in both the Netherlands and some cases people were taken out to sea low tides, as some areas of the hook of the Texas, it is a top priority to protect coastal with the currents (Schipper et al., 2016, Stive Sand Engine become secluded from the rest infrastructure (Stive et al., 2013). In order to et al., 2013). If a nourishment system in similar of the nourishment with the presence of high maintain these coastal opportunities and design to the Sand Engine was placed in tide (de Schipper et al., 2016). Depending on economic benefits, beaches must be properly Galveston or surrounding Texas coast, extra the location of parked cars or even people, nourished (NRC, 1995). safety precautions would have to be taken some could become stranded with high tides with beach goers to ensure their changing if a design similar to the Sand Engine was The cost of beach nourishments varies widely surroundings are known. 206 created. depending on the location, labor required, 207 Figure 5 (right). The exact effects of a decreased water flow org/10.2112/SI61-001.11 Case Study. DHV Group. Retrieved from Recreational use would depend on the area in which a mega- de Groot, A. V., de Vries, S., Keijsers, J. G. S., http://www.projects.eucc-d.de/files/000139_ of Sand Engine: nourishment is placed, the type of soil in the Riksen, M. J. P. M., van Ye, Q., Poortinga, A., … EUROSION_Holland_coast.pdf kite surfing (Image surrounding areas, the average rainfall, and van Thiel de Vries, J. S. M. (2012). Measuring van Slobbe, E., de Vriend, H. J., Aarninkhof, courtesy Leo severity of storm surges. and modeling coastal dune development S., Lulofs, K., de Vries, M., & Dircke, P. (2013). Linnartz). in the Netherlands. University of Twente, Building with Nature: in search of resilient Conclusions Department of Water Engineering & storm surge protection strategies. Natural Figure 6 (far right). Coastal flooding is constant concern across Management. https://doi.org/10.3990/2.178 Hazards, 66(3), 1461–1480. https://doi. Pioneer vegetation world, with the present threat of storms and Leatherman, S. P. (1989). National assessment org/10.1007/s11069-013-0612-3 at Sand Engine sea level rise (Stive et al., 2013). Protecting of beach nourishment requirements Stive, M. J. F., de Schipper, M. A., Luijendijk, (Image courtesy Leo both local people and infrastructure is a associated with accelerated sea level rise. A. P., Aarninkhof, S. G. J., van Gelder-Maas, Linnartz) necessity to maintain life and economic The Potential Effects of Global Climate C., van Thiel de Vries, J. S. M., … Ranasinghe, desires along coastal regions. While there Change on the United States: Appendix R. (2013). A New Alternative to Saving are many variations of engineering designs B—Sea Level Rise. Retrieved from http:// Our Beaches from Sea-Level Rise: The used along coasts, the importance of www.papers.risingsea.net/federal_reports/ Sand Engine. Journal of Coastal Research, well-nourished beaches is a technique rtc_leatherman_nourishment.pdf 290, 1001–1008. https://doi.org/10.2112/ commonly implemented across the world, Misachi, J. (2016). Biggest Cities In The JCOASTRES-D-13-00070.1 including in Netherlands and Texas. A recent Netherlands. Retrieved June 22, 2017, from Stive, M. J. F., de Schipper, M., Luijendijk, replenishment method through the use http://www.worldatlas.com/articles/biggest- A., Ranasinghe, R., Van Thiel de Vries, J., As the Sand Engine has continued to evolve, divert any changes to the water system was 2014). However, with the presence of a mega- of a mega-nourishment was found in the cities-in-the-netherlands.html Aarninkhof, S., … Marx, S. (2013). The Sand the hazards from the lagoon channel have to implement a lake feature into the design. nourishment such as the Sand Engine, the innovative Sand Engine pilot project in the Mulder, J. P., & Tonnon, P. K. (2011). “Sand Engine: A Solution for Vulnerable Deltas decreased. According to de Schipper (2017), The purpose of this feature was to maintain distance the water must travel to reach the Netherlands (Stive et al., 2013). This project Engine”: Background and design of a mega- in the 21st Century? Bordeaux University. it has been found that the channel that the current location of the freshwater lens. ocean has significantly increased, increasing has revealed how an engineered coastal nourishment pilot int he Netherlands. Coastal Retrieved from https://ewn.el.erdc.dren.mil/ leads to the lagoon has slowly been filling in If the lens were to move, then this could the time required for local flooding to protection structure can be both resilient and Engineering Proceedings, 1(32), 35. Retrieved workshops/2016March_NNBF/electronic%20 with sediment over the course of the Sand threaten water extraction by stakeholders subside. multifunctional (van Slobbe et al., 2013). Many from https://icce-ojs-tamu.tdl.org/icce/index. library/18%20Coastal%20Dynamics%20-%20 Engine’s morphology. This accretion has (de Schipper et al., 2016). The lake feature is of the multifunctional outcomes have been php/icce/article/view/1454 The%20Sand%20Engine.pdf caused inflow water velocities to decrease, currently performing their expected results The relationship between discharge velocity positive enhancements to the surrounding National Research Council. 1995. Beach UN [United Nations] (2007). Percentage of producing less of a threat to beach goers. (de Schipper et al., 2017). However, changes and saturated soil can be understood by area, while some other negative byproducts Nourishment and Protection. Washington, DC: Total Population Living in Coastal Areas. U.N. The ability for a mega-nourishment to could always occur as the morphological Darcy’s Law. Darcy’s Law of discharge have presented new challenges. Although The National Academies Press. doi:https://doi. Division for Sustainable Development. http:// create threatening rip currents is a potential processes continue. This aspect of controlling velocity (v), represented by equation some of the outcomes are dependent on org/10.17226/4984. www.un.org/esa/ problem that could be seen if placed along a water table within a dune could be a design the location, size, and design chosen for NOAA [National Oceanic and Atmospheric sustdev/natlinfo/indicators/methodology_ the Texas coastline. This would greatly consideration if a mega-nourishment were (1) v=k*i, a mega-nourishment, some similar results Administration] (2016). “What percentage sheets/oceans_seas_coasts/ depend on the location chosen for the implemented in Texas. This would depend on could be expected if placed along the Texas of the American population lives near the pop_coastal_areas.pdf. Retrieved May 23, mega-nourishment and the dynamics of the the location of the mega-nourishment and if is used to determine the velocity at which coastline. Overall, the Texas coastline could be coast?” http://oceanservice.noaa.gov/ 2017. environment. However, such a threat is still to maintaining the water table’s position was a water can travel through saturated soil. greatly benefited by the potential protection facts/population.html. Retrieved May 23, USACE [U.S. Army Corps of Engineers] be considered. necessity. Hydraulic conductivity (k) is dependent on and multi-functional opportunities provided 2017. (1993). Activities to Reduce Erosion Losses the type of soil present and is measured in through the presence of a mega-nourishment. Rozier, S. (n.d.). Projects. Retrieved August 27, Along the Texas Gulf Coast [Scholarly - Fresh Water Management - Flood Mitigation the units of length/time. Hydraulic gradient 2017, from http://www.galvestonparkboard. project]. U.S. Army Engineer District, The presence of a well-nourished coast With the immediate introduction of a large (i) can be found by the equation org/200/Projects Galveston (June 1993). Retrieved June 20, can also hold an important multi-functional volume of sand along the coast, other References de Schipper (2017). Personal Interview. 2017, from http://hdl.handle.net/1969.3/28661 value by providing drinking water (Mulder unforeseen results could occur. In a rainfall (2) i=∆h/L, Campbell, T. J., & Benedet, L. (2004). Beach Conducted June 8, 2017. Wong, T. E., Batjes, D. A. J., Jager, J. ., & and Tonnon, 2011). Water in the Netherlands event, water that accumulates on the ground nourishment magnitudes and trends in the de Schipper, M. A., de Vries, S., Ruessink, G., Koninklijke Nederlandse Akademie van holds a high economic significance. Due to must eventually drain to new location or else where ∆h is the head loss and L is the length US. Journal of Coastal Research, 39. Retrieved de Zeeuw, R. C., Rutten, J., van Gelder-Maas, Wetenschappen. (2007). Geology of the this it is important to protect sources of fresh flooding will occur due to water build up. This at which the water must travel from the point from http://siaiacad09.univali.br/ics2004/ C., & Stive, M. J. F. (2016). Initial spreading of Netherlands. Amsterdam, Netherlands: Royal water (Sistermans and Nieuwenhuis, 2004). water can be dispersed by flowing through of high energy to a point of low energy (Das arquivos/09_tom.pdf a mega feeder nourishment: Observations Netherlands Academy of Arts and Sciences. A concern with the construction of the Sand permeable soil or to localized drainage areas and Sobhan, 2014). Simply through Darcy’s Das, Braja M., and Khaled Sobhan (2004). of the Sand Engine pilot project. Coastal Engine was the effects to the quality of (Das and Sobhan, 2014). As prolonged rainfall Velocity equation it can be seen that as the Principles of geotechnical engineering. 8th ed. Engineering, 111, 23–38. https://doi. freshwater that is held in the dunes around events occur and groundwater builds up, length increases, the velocity decreases. If Australia: Cengage Learning. org/10.1016/j.coastaleng.2015.10.011 the mega-nourishment. The question was water moves to drain from a point of high applied to the case of a mega-nourishment Giardino, A., Mulder, J., de Ronde, J., Scranton, R. (2016). When the Next Hurricane how such a large volume of sand placed in gravitational potential energy to a point in which beach width has significantly & Stronkhorst, J. (2011). Sustainable Hits Texas. Retrieved June 20, 2017. https:// front of the dunes would affect such a valued of low gravitational potential energy. For increased, the length of travel between high Development of the Dutch Coast: Present and www.nytimes.com/2016/10/09/opinion/ water source (van Slobbe et al., 2013). While regions along the coast, the point of lowest and low points will also increase. This would Future. Journal of Coastal Research: Special sunday/when-the-hurricane-hits-texas.html the exact results of the mega-nourishment potential energy for groundwater is generally cause the discharge water flow velocity Issue 61 - Management of Recreational Sistermans, P., & Nieuwenhuis, O. (2004). 208 were not known at the time, one solution to considered to be the ocean (Das and Sobhan, to decrease, and cause potential flooding. Resources: pp. 166 – 172. https://doi. Holland Coast (The Netherlands). EUROSION 209 Figure 1. The location Connie Do of the Sand Engine along the Dutch Coast (de Schipper SEDIMENT VOLUME ESTIMATIONS FOR A MEGA-NOURISHMENT et al., 2016) ON FOLLET’S ISLAND SAND ENGINE

Connie is graduating from Rice University single, mega- nourishment was introduced The Sand Engine this year with a B.Sc. in Chemical Engineering. which consists of placing a large volume - The Design She is entering the M.S. in Environmental of sand at a single location to feed a larger In 1990, the “Dynamic Preservation” policy Engineering program, also at Rice University. extent of coast over time (de Schipper et al., was implemented by the Dutch government 2016). Mega-nourishments are anticipated to maintain the current coast line position, to be more efficient, economical, and coined the Basal Coast Line (BCL), to Beaches are highly valuable features of environmentally friendly in the long term than enhance flood protection and preserve the coastlines as they provide opportunities traditional beach nourishment (Stive et al., quality and functions of the coast. The annual for recreation, aesthetic value, storm surge 2013). average nourishment volume was then protection, and more. Anthropogenic raised from 6 Mm3 to 12 Mm3. This increase pressures such as increasing urban In 2011, a mega-nourishment project called in nourishment volumes spearheaded a development and damming are disrupting the Sand Engine was implemented in the discussion to implement the Sand Engine, the sediment budget (Nordstrom, 2000). Netherlands. The feature consisted of a locally concentrated mega-nourishment For example, large man-made structures about 21 million m3 of sand in the shape project of approximately 20 Mm3 along such as jetties can interfere with the natural of a large hook. A combination of wind, the “Westland” Coastal Cell, 17 km of coast hydrodynamic system of waves and waves and tides was expected to mould between the Hoek van Holland and the currents, thus affecting sand transport rates the Sand Engine and feed adjacent coasts harbor entrance at Scheveningen (Figure 1) that control beach morphology (Wijnberg, over time. Frequent surveys and analyses (de Schipper et al., 2016). 2002). of the morphological development of the Sand Engine show predominant alongshore Assistant Professor of Coastal Engineering at Over 70% of the world’s beaches are in redistribution of sediment, which is consistent Delft University of Technology, Dr. Matthieu recession (Bird, 1996). A variety of hard with expectations (de Schipper et al., 2016). de Schipper, states that the Sand Engine and soft engineering measures have been The potential long term success of the Sand pilot project emerged from a desire to implemented to help combat the effects of Engine sparks conversation as to whether increase safety against flooding, increase the beach erosion. Hard engineering consists a mega-nourishment can be experimentally living quality of the coastal community, and Figure 2. Sand of constructing hard structures such as implemented elsewhere. explore innovative ways of nourishing larger Engine designs seawalls and groynes to protect valuable volumes of sand (M. de Schipper, personal as a shoreface properties and encourage beach accretion. Follet’s Island is a barrier island on the upper communication, June 8, 2017). Several nourishment (left), a Soft engineering consists of less ecologically Texas Coast experiencing rapid shoreline designs for the Sand Engine were studied in bell shape (middle) invasive measures such as artificial erosion rates. This transgressive property order to evaluate the morphological effects and a hook shape nourishment to replenish sediment and makes the island a potentially viable on a decadal time scale. A Delft3D model (right) of 20 Mm3 (J. extend the beach seaward. location for a mega-nourishment project. (Lesser, Roelvink, van Kester, & Stelling, 2004) P. Mulder & Tonnon, The objective of this study is to report an coupled with SWAN (Holthusien et al., 1993) 2011) Sand nourishments potentially promote estimate for the volume of sand necessary for and TRANSPOR2004 (van Rijn, 2007a,b,c) as two positive effects: wave attenuation and a mega- nourishment on Follet’s Island based well as a dune model developed by De Vriend cross-shore feeding (J. P. M. Mulder, Kreeke, on its transport potential. The calculations and Roelvink in 1989 (J. P. Mulder & Tonnon, & Vessem, 1994). Shoreface nourishments performed in this analysis utilize the design 2011) showed that the morphological effects are carried out approximately every 3 to 10 strategies of the Dutch Sand Engine. It is of different sand engine design alternatives years depending on the extent of the regions’ hypothesized that a mega- nourishment on (Figure 2) , were similar on a long term (20- annual sand deficit (Cooke, Jones, Goodwin, Follet’s Island will be of greater magnitude 50 yrs) scale. Ultimately a hook formation & Bishop, 2012). The potentially negative than the Sand Engine due to a lack of was chosen. ecological effect of frequent re-nourishment stringent shoreline preservation initiatives as Assistant Professor of Coastal Engineering has led to discussions of improved methods observed in the Netherlands. at Delft University of Technology, Dr. 210 of sand replenishment. The concept of a Sierd de Vries, states that the process 211 Figure 3. Sand behind determining the volume of the equal to the rate of shoreline retreat (Wallace, study, the most recently available dataset 1953 to 2006 (Paine, Mathew, & Caudle, 2012). Engine surveys from sediment for the Sand Engine began with Anderson, & Fernández, 2010). Wallace et. al. from the previously released report in 2007 The mega-nourishment on Follet’s Island is 2011 (top) and 2015 understanding the transport potential of also concluded that Follet’s Island is sediment was used for this study’s calculations. The assumed a lifetime of 20 years like the Sand (bottom). Image the Westland Coastal Cell (S. de Vries, starved because the upper and lower 2012 report showed that the net rate of Engine. provided by TU Delft. personal communication, June 9, 2017). shoreface contain only ~2 m and ~1 m of sand, change in Brazoria County, where Follet’s The yearly-averaged transport rates near respectively. Follet’s Island experiences high Island is located, only increased by 2% from According to the 2013 IPCC report, the the middle of the cell are about 7.6 105 m3 rates of background erosion due to cross- -0.42 m/yr in 2007 to -0.43 m/yr in 2012. rate of global sea level rise is expected to northward and 3.8 105 m3 southward (van shore and longshore sediment transport. Hurricane Ike significantly impacted this increase throughout the 21st century due to Rijn, 1995). In order to maintain the coastal region when it struck the upper Texas coast increased ocean warming and increased loss foundation of the region for approximately Brazos River Diversion in September 2008. The erosion, deposition, of mass from glaciers and ice sheets (IPCC, 20 years, ~21 Mm3 of sediment dredge In the early 1920s, the Freeport Harbor was and recovery periods post-Hurricane Ike 2013). It is difficult to predict how much the was acquired 5-10 km offshore to form the experiencing high maintenance costs due are likely a large influence on the shoreline rate will increase in the next few decades, Sand Engine. This volume calculation took to siltation from frequent flooding (Fox, change rates from 2007 to 2012. Since the but modeling a range of greenhouse gas into consideration the current average sea 1931). With funding through the Rivers and average change rate for the entire region in concentration trajectories showed that level rise rate of 2 mm/yr (J. P. Mulder & Harbors Act of March 1925, the construction 2012 is nearly identical to the average change global mean sea level can increase anywhere Tonnon, 2011). The average grain size of the of a diversion dam and the dredging of a rate from the 2007 report (-1.24 m/yr), the between 0.26 m to 0.82 m by the year sediment (D50) used for nourishment was diversion channel was approved in order data set from 1930-2007 was deemed an 2100. In this study, the volume of a mega- 281 microns. The hook shape that was chosen to convert the current channel leading to acceptable estimation of average shoreline nourishment is also estimated for increased contained a peninsula curved northward the mouth of the Brazos River into a tidally retreat rates on Follet’s Island on a long-term sea level rise rate scenarios. and a small lake at the base to prevent the controlled harbor (Morton & Pieper, 1975). scale. This paper’s study used a subset of freshwater lens in the dunes from migrating By September 1929, the mouth of the river the BEG data consisting of end point rates, The relationship between sea level rise and seaward (de Schipper et al., 2016). The was relocated 6.5 miles westward. In order rates of change from around 1930 to 2007 profile response of a barrier island can be most seaward position of the Sand Engine to assess the evolution of the region from determined from the earliest and most recent approximately described using an equation was approximately 1 km from the original San Luis Pass to Brown Cedar Cut prior to shoreline position averaged over the elapsed (Eqn. 2) introduced by Dean and Maurmeyer shoreline. The construction of the Sand the construction of the diversion channel, time (Figure 6). The shoreline change rates (1983). This equation expands on the Bruun Engine lasted from March 2011 to July 2011. topographic charts dating from 1850, in 2007 were calculated by importing aerial rule which is based on the assumptions that available through the National Oceanic and imagery and locating shoreline proxies that the equilibrium profile shape of a shoreline - The Evolution Atmospheric Administration (NOAA) were were established from previous years. Rates does not change with respect to the water Since its implementation, the Sand Engine mapped by the U. S. Coast Survey using of change were then determined at transect line and that the sand volume in the profile has exhibited a reworking of its original plane table procedures (Morton & Pieper, locations cast at 50 m intervals along the is conserved. The Dean and Maurmeyer asymmetrical shape to a nearly symmetrical 1975). Morton and Pieper calculated shoreline shoreline (Paine, Mathew, & Caudle, 2011). equation assumes that the entire barrier shape (Figure 3). As of 2015, the Sand Engine rates of change between 1852-56 and 1974 island will migrate landward with an increase has experienced a net loss of almost 1 Mm3 at 44 arbitrary points spaced 5,000 ft apart Methodology in vertical elevation (Figure 7) (Dean & of sediment. Both adjacent coasts of the (Figure 5). Points 1 through 15 make up the In the Netherlands, the volume calculation for Dalrymple, 2004). peninsula exhibit accretion with the northern entirety of Follet’s Island before the old a beach nourishment is as follows: adjacent coast experiencing a larger volume Brazos River delta. The Dean and Maurmeyer equation to solve

addition than the southern coast. This reflects VN = Qm * T (1) for landward displacement R in m/yr is as the net northward transport of sediment Immediately after the Brazos River diversion, follows

observed in van Rijn’s 1995 study. Since the Follet’s Island experienced an increase in where Qm represents the loss of sand per (2) intention of the Sand Engine design was shoreline erosion rates from 1930 to 1956 coastal section in m3/yr and T represents to promote feeding of adjacent coasts, the (Table 1). Before the diversion, Follet’s Island the desired lifetime of the nourishment where S is the rate of sea level rise in m/yr,

nourishment’s morphodynamic behavior has experienced an average erosion rate of (Verhagen, 1993). This method assumes the LO and LL represent the width in meters of exhibited success in this respect. ~1 m/yr. This value increased to ~5m/yr post- erosion rate before nourishment equals the the active profile on the ocean and lagoon

diversion. erosion rate after nourishment. According to side, respectively, hOand hL represent the Follet’s Island Dr. de Vries, this was the method used during initial water level in meters of the ocean and Follet’s Island is a barrier island located on Data Acquisition the volume calculation for the Sand Engine. lagoon, respectively, and W represents the the Upper Texas Coast (Figure 4) that is Shoreline change data on Follet’s Island was The average erosion rate from Figure 6 was width of the barrier island in meters. A bay sediment starved as a result of rerouting of obtained through the Bureau of Economic multiplied by the alongshore distance of 25 depth of approximately 1 m and an ocean the Brazos River in the 1920s (Harter and Geology (BEG). The BEG recently released km and an average island thickness of 3 m depth of approximately 5 m were taken for Figlus, 2017). The island is approximately their updated Gulf Coast shoreline evolution to obtain a volume loss in m3/yr (Morton, a distance of 800 m offshore on both sides 25 km long and less than 500 m wide with an report titled Shoreline Movement along the 1994). The current relative sea level rise rate of the island (Frost, 2015). Equation 2 was elevation of about 2 m (NAVD 88). The island Texas Gulf Coast, 1930’s to 2012. However, at Follet’s Island was taken to be ~4.4 mm/ solved for projected erosion rates using is said to be in its “rollover phase” because because the updated 2012 data set was not yr. This value was obtained from sea level rise increased relative sea level rise rates of 5 212 the landward bayline movement is almost yet made publicly available at the time of this data acquired at the Freeport tide gage from mm/yr and 8 mm/yr. An erosion rate was also 213 Figure 4. Follet’s calculated using the current rate of sea level the increase in relative sea level rise scales calculated value, but further studies should References island area map rise for comparison with the BEG data. Mega- approximately linearly with erosion rate be conducted to evaluate the actual accuracy Bird, E.C.F., 1996. Beach Management. Wiley, showing important nourishment volumes were then calculated (Equation 2), the potential increase in mega- of either method in calculating the size of a Chichester, UK, 292 pp economic assets for all sea level rise scenarios. nourishment volume in the long term should mega- nourishment. Relative sea level rise Coastal Studies, Bureau of Economic such as the port be addressed and factored into designs. should be taken into consideration during Geology. (n.d.). Retrieved July 14, 2017, from of freeport, the Results and Discussion the design of a mega- nourishment because http://www.beg.utexas.edu/coastal/ Gulf Intracoastal The mega-nourishment volumes calculated It is interesting to note that for a higher an increase in relative sea level rise leads to download.php Waterway (GIWW), for each sea level rise scenario are presented relative sea level rise rate and larger an increase in the required volume. This can Cooke, B. C., Jones, A. R., Goodwin, I. D., & and the CR-257 in Table 2 below.. alongshore extent than the Westland potentially put a strain on the availability of Bishop, M. J. (2012). Nourishment practices on highway as well as Coastal Cell, Follet’s Island requires a mega- suitable sediment for a mega-nourishment. Australian sandy beaches: A review. Journal ecological assets like Table 2. Mega-nourishment volume calculations. nourishment volume about 15% of the Sand of Environmental Management, 113, 319–327. Christmas Bay and Engine. There are a number of factors that There is a possibility that the volume https://doi.org/10.1016/j.jenvman.2012.09.025 the Brazoria National Sea Level Rise Scenario Volume Estimation (Mm3) could contribute to this observation including calculated by the Dutch design method Cooper, J. A. G., & Pilkey, O. H. (2004). Wildlife Refuge (C. Current (using BEG data) 2.7 differences in geological characteristics, might not accurately represent the necessary Sea-level rise and shoreline retreat: time Harter & Figlus, 2017) Current (using Dean and Maurmeyer Eqn.) 3.4 wave climate, meteorological forcings, etc. size of a mega-nourishment on Follet’s Island. to abandon the Bruun Rule. Global and Projected (5 mm/yr) 3.9 between the Texas and Dutch coastlines Studies evaluating the coastal processes and Planetary Change, 43(3–4), 157–171. Projected (8 mm/yr) 6.3 that impact the annual alongshore transport other factors on Follet’s Island that might https://doi.org/10.1016/j. potential. Additionally, since the calculations impact the evolution of a mega-nourishment gloplacha.2004.07.001 The volume of a 20-year mega-nourishment in this study were based on the Dutch differently than the Sand Engine are crucial de Schipper, M. A., de Vries, S., Ruessink, G., on Follet’s Island using average shoreline nourishment design strategy (Equation 1), for providing the most accurate volume de Zeeuw, R. C., Rutten, J., van Gelder-Maas, retreat data is 2.7 Mm3 (see Appendix A further studies comparing characteristics estimate. These studies will help determine if C., & Stive, M.J. F. (2016). Initial spreading of for calculations). This volume assumes the across both coastlines would provide a Follet’s Island is indeed a strong candidate for a mega feeder nourishment: Observations current relative sea level rise rate of 4.4 mm/ better understanding of whether or not the next mega-nourishment experiment and of the Sand Engine pilot project. Coastal yr will remain constant during the lifetime modifications to Equation 1 should be if the island’s vulnerable shoreline will benefit Engineering, 111, 23–38. https://doi. of the mega-nourishment. The volume made in order to accurately represent the from the project in the long-run. org/10.1016/j.coastaleng.2015.10.011 Dean, calculated from the BEG shoreline retreat morphological behavior observed on Follet’s R. G., & Dalrymple, R. A. (2004). Coastal rates differ from the volume calculated Island. processes with engineering applications. by the Dean and Maurmeyer equation by Cambridge University Press. Retrieved from about 700,000 m3. It is highly likely that An example characteristic to further consider http://books.google.com/books?hl=en&lr=& Figure 5. Map the assumptions made by the Dean and would be the frequent occurrence of id=XlDmIdpqMFYC&oi=fnd&pg=PP13&dq=% displaying points Maurmeyer equation over-simplify and/or hurricanes in the Gulf Coast and the impacts 22ONE. +INTRODUCTION+TO+COASTAL% of measurement misrepresent the morphological behavior on the geomorphology of Follet’s Island. 22+%22Development+of+Equilibrium+Beac (Morton & Pieper, of Follet’s Island. The Bruun Rule ignores Extreme storms such as Hurricane Ike have h+Pro%EF%AC%81l e%22+%22book,+which 1975) important geological principles and should historically resulted in significant cross-shore +deals+primarily+with+sandy+coastlines,+is only be used to give an order-of- magnitude transport of sediment on Follet’s Island (C. +divided+into+four%22+%22 Tides+and+Sto estimate of shoreline retreat (Cooper & F. Harter, 2015). The impacts of extreme rm%22+%22coastal+engineering,+nearshore Pilkey, 2004). Thus, the Dean and Maurmeyer storms on the magnitude and direction of +oceanography,+and+marine+geolo gy.+Alt equation helps to confirm the order of the sediment flux on Follet’s Island should hough%22+&ots=FRrqzX4dNc&sig=lyoh8rJ magnitude of the volume calculation using be considered carefully as they could highly id_MxFimtpeKUY6JncyM the BEG data, but further studies should influence the ideal size, shape, and feasibility Fox, M., 1931, Improving the Brazos River: Civil be performed to determine the accuracy of a mega-nourishment. Eng., v. 1., p. 287-292. of either method in determining a mega- Frost, K. E. (2015). Hyrdrodynamic and nourishment volume on Follet’s Island. Conclusion Sedimentary Response to Tropical Storm The Dutch Sand Engine is a model for future Bill in the Gulf of Mexico and Christmas Mega-nourishment volume estimates in mega-nourishments, and it is important Bay. Retrieved from http://oaktrust.library. the event of increased relative sea level to assess the adaptability of its design tamu.edu/handle/1969.1/156523 Harter, C. F. rise rates are shown in the bottom rows of strategies in other vulnerable locations (2015). The impact of Hurricane Ike on the Table 2. These calculations assume that the around the world. The sediment volume geomorphology of Follet’s Island, Texas - physical characteristics of the island are estimate of ~2.7 Mm3 using the BEG shoreline Short and Long Term Effects (M.Sc. Thesis). the same as those used for the current sea retreat data may serve as a ballpark value Texas A&M University, College Station. level rise scenario. Since these volumes were during preliminary design considerations Harter, C., & Figlus, J. (2017). Numerical calculated using the Dean and Maurmeyer for a mega-nourishment on Follet’s Island. modeling of the morphodynamic response of equation, they can only provide rough order- The Dean and Maurmeyer equation aids in a low-lying barrier 214 of-magnitude approximations. However, since justifying the order-of-magnitude of the island beach and foredune system 215 Table 1. Shoreline inundated during Hurricane Ike using Texas Gulf Coast: rates, contributing causes, Appendix A. retreat rates XBeach and CSHORE. Coastal Engineering, and Holocene context. Gulf Coast Association acquired for Follet’s 120, 64–74. https://doi.org/10.1016/j. of Geological Societies Journal, 1, 13–26. Current_BEG Island pre- and coastaleng.2016.11.005 Stive, M. J. F., de Schipper, M. A., Luijendijk, R_BEG (m/yr) 1.8 post- Brazos River Holthuijsen, L.H., Booij, N., and Ris, R.C. (1993). A. P., Aarninkhof, S. G. J., van Gelder-Maas, Length (m) 25000 Diversion. The red A spectral wave model for the coastal zone. C., van Thiel de Vries, J. S. M., ... Ranasinghe, Thickness (m) 3 box indicates the Proc. of the 2nd Int. Symposium on Ocean R. (2013). A New Alternative to Saving Volume Loss ,3/yr) 135000 period immediately Wave Measurement and Analysis, New Our Beaches from Sea-Level Rise: The Lifetime (yr) 20 following the Orleans, 630-641. Sand Engine. Journal of Coastal Research, Total Volume (m3) 2700000 diversion. (Wallace et IPCC, 2013: Summary for Policymakers. In: 290, 1001–1008. https://doi.org/10.2112/ al., 2010) Climate Change 2013: The Physical Science JCOASTRES-D-13-00070.1 Current _DandM Basis. Contribution of Working Group I Van Rijn, L. C. (1995). Sand budget and L_O (m) 800 to the Fifth Assessment Report of the coastline changes of the central coast of L_L (m) 800 Intergovernmental Panel on Climate Change Holland between Den Helder and Hoek van h*o (m) 5 [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, Holland, period 1964-2040. H2129. Retrieved h*l (m) 1 S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. from https://repository.tudelft.nl/islandora/ W (m) 500 Bex and P.M. Midgley (eds.)]. Cambridge object/uuid:6837af90-6f12-4f14-ac73- 4d697 S (m/yr) 0.00435 University Press, Cambridge, United Kingdom 8f72f47?collection=research R (M/yr)= 2.28375 and New York, NY, USA. Van Rijn, L.C. (2007a). United view of Length (m) 25000 Lesser, G. R., Roelvink, J. A., van Kester, J. A. sediment transport by currents and waves Thickness (m) 3 Figure 6. Average T. M., & Stelling, G. S. (2004). Development I: Initiation of motion, Bed roughness and Volume Loss (m3/yr) 171281.3 shoreline retreat and validation of a three-dimensional Bed load transport. Journal of Hydraulic Lifetime (yr) 20 rates or end point morphological model. Coastal Engineering, Engineering, ASCE, Vol. 133, No. 6, p.649-667. Total Volume 3425625 rates on Follet’s 51(8–9), 883–915. https://doi.org/10.1016/j. Van Rijn, L.C. (2007b). United view of Island from 1930- coastaleng.2004.07.014 sediment transport by currents and waves Projected_DandM 2007. The average Morton, R. A., & Pieper, M. J. (1975). Shoreline II: Suspended transport Journal of Hydraulic L_O (m) 800 rate of erosion changes in the vicinity of the Brazos river Engineering, ASCE, Vol. 133, No. 6, p. 668-689. L_L (m) 800 across the entire 25 delta (San Luis Pass to Brown Cedar Cut) - Van Rijn, L.C. (2007c). United view of h*o (m) 5 km coast was ~1.8 m/ An analysis of historical changes of the Texas sediment transport by currents and waves h*l (m) 1 yr. (“Coastal Studies, Gulf shoreline (Geological Circular No. 75–4) III: Graded Beds. Journal of Hydraulic W (m) 500 Bureau of Economic (p. 50). Austin, TX: Texas Bureau of Economic Engineering, ASCE, Vol. 133, No. 7, p. 761-775. S (m/yr) 0.005 Geology,” n.d.) Geology. Verhagen, H. J. (1993). Method for R (M/yr)= 2.625 Mulder, J. P. M., Kreeke, J. van de, & Vessem, artificial beach nourishment. In Coastal Length (m) 25000 P. van. (1994). EXPERIMENTAL SHOREFACE Engineering 1992 (pp. 2474– 2485). Thickness (m) 3 NOURISHMENT, TERSCHELLING (NL). Retrieved from http://ascelibrary.org/doi/ Volume Loss (m3/yr) 196875 Coastal Engineering Proceedings, 1(24). abs/10.1061/9780872629332.189 Lifetime (yr) 20 Retrieved from https://icce-ojs-tamu.tdl.org/ Wallace, D. J., Anderson, J. B., & Fernández, R. Total Volume 3937500 icce/index.php/icce/article/view/5152 A. (2010). Transgressive Ravinement versus Mulder, J. P., & Tonnon, P. K. (2011). “Sand Depth of Closure: A Geological Perspective Projected_DandM Engine”: Background and design of a mega- from the Upper Texas Coast. Journal of L_O (m) 800 nourishment pilot int he Netherlands. Coastal Coastal Research, 26, 1057–1067. https://doi. L_L (m) 800 Engineering Proceedings, 1(32), 35. org/10.2112/JCOASTRES-D-10-00034.1 h*o (m) 5 Nordstrom, K.F., 2000. Beaches and Dunes Wijnberg, K. M. (2002). Environmental h*l (m) 1 of Developed Coasts. Cambridge University controls on decadal morphologic behaviour W (m) 500 Figure 7. Barrier Press, Cambridge, U.K of the Holland coast. Marine Geology, 189(3), S (m/yr) 0.008 island equilibrium Paine, J. G., Mathew, S., & Caudle, T. (2011). 227–247. R (M/yr)= 4.2 response (from Dean Texas gulf shoreline change rates through Length (m) 25000 and Maurmeyer 2007. Bureau of Economic Geology. Thickness (m) 3 1983) (Dean & Retrieved from https://repositories.tdl.org/ Volume Loss (m3/yr) 315000 Dalrymple, 2004) tamug- ir/bitstream/handle/1969.3/29271/ Lifetime (yr) 20 begTexasGulfShorelineReport2011_highRes. Total Volume 6300000 pdf?sequence= 1 Paine, J. G., Mathew, S., & Caudle, T. (2012). 216 Historical shoreline change through 2007, 217 Figure 1: Bella Jezierski Relationship of vegetation to sediment, THE SYNERGETIC EFFECT OF PROPAGATING CONGENER SPE- hydrodynamics and dune changes CIES OF AMMOPHILIA ON EROSION REDUCTION OF DUNES (Sigren, 2017 SAND ENGINE

Bella is a Marine Resource Management stress due to sediment dynamics. Higher root adapted to dry sand. Leaves roll and tighten graduate student at Texas A& M University densities in a soil would therefore increase when the moisture levels are low (Gadgil, in Galveston. She is also currently a teaching dune erosion resistance through the physical 2006). assistant in Chemistry at TAMUG. mechanism of shear stress reinforcement. AMBR appear virtually identical to AMAR, but Since vegetation plays a fundamental role it produces more lateral rhizomes with larger Vegetation reconstructions of historical open in building and stabilizing dune systems tillers compared to the tussock-like growth dune habitats and enhancing vegetation (Frosini, 2012), this study aims to focus form of AMAR (Hacker, 2012). Nevertheless, density are very difficult (Provoost et al., 2011) on identifying if there is any synergistic both species have not been historically because coastal dune plants are subjected effect between Ammophila arenaria (plant recognized as separate species in the field. to natural multiple stresses and vulnerable code: AMAR) and its congener, Ammophila Both grasses can be propagated using three to global change (Frosini, 2012). Coastal breviligulata (plant code: AMBR) when different methods: planting bundles of culms dune landscapes have been drastically propagated in similar dune system. AMAR, (traditional method), sowing seeds, and altered through centuries of anthropogenic also known as marram grass, a native disc-harrowing rhizomes. A.arenaria and exploitation and, more recently, the urban species that dominates the foredunes of A.breviligulata are highly adaptive in sand, development of the coast (Provoost et al., northwestern Europe has natural ability to can stand burial for more than one year and 2011). Historical land use has generally pushed colonize and stabilize sand dunes and is often elongate its leaves when buried by sand Figure 2: vegetation back into a semi-natural state. used for erosion control (Rodriguez et al., (Ranwell, 1960). Its inflorescences are always A sample 2008). It is a perennial, rhizomatous grass produced from May to August and mature photograph of small- The role of dune vegetation in potentially that needs regular burial by wind-blown in September. Sowing seeds at 200, 400 scale wave flume reducing the amount of energy eroding sand to grow vigorously and thrives where and 600 meters showed increased numbers set up with planted landward sediments by increasing the sand accretion is intense (Rodriguez et al., of seedlings and primary shoot (Rodriguez vegetation (Figlus, et. dissipation of wave energy, reducing of wave 2008). The grass forms stiff, hardy clumps of et al., 2008). Once the seeds are buried, it al.,2014) reflection, swash/backwash velocities and erect stems up to 1.2 meters in height. One germinates in the next spring. Even though turbulence were established in experimental clump can produce 100 new shoots annually the plant is strong in live, it has low viability studies (Sigren, 2017). The pattern of erosion and it can grow series of thick rhizomes for seeds because of desiccation, burial and and accretion is strongly controlled by the that can grow laterally by 2 meters in six erosion (Russo, 1988). vegetation cover (Arens, 1995). Plants can months (Apteker, 2008). Growing rhizomes reduce dune erosion in two ways: substrate gives the grass sturdy anchor in its sandy This study will provide unique opportunities modification belowground and hydrodynamic substrate. This species is generally considered to understand the mechanisms that will modification aboveground (Figure 1, Sigren, to be the most important sand-fixing plant impact invasion morphology of Ammophila 2017). species along the northwestern European congeners. Typically, non-native congeneric and Mediterranean coast, and it is planted species are compared to native ones to Plant roots could influence wave collision in worldwide for sand dune stabilization explore how morphological and physiological two ways. The first involves below-ground (Rodriguez et al., 2008). similarities may allow non-native species to aggregation/binding through bacterial and invade or colonize the new habitat (Hacker fungal decomposition that secretes adhesive Marram grass et.al., 2012). Differences in traits such as compounds aiding entanglement of sediment Marram grass is a native on coastal sand growth form, reproductive mode, or survival particles by roots hairs (Sigren, 2017). This dunes of Europe and South Africa. It suits affects the invasion rates. This will ultimately means, higher amounts of mycorrhizal pH soil range of 4.5-9. 0, temperature determine how congeners establish activity and roots present in soil could ranges from 10-40 degrees 0 C and salt themselves and spread (colonize), interact increase the binding of sediment and erosion concentrations of no more than 1-1.5 % with one another that eventually affect the resistance. Second, plant roots increase the (Ranwell, 1960). Adult plants tolerate a community structure. It was noted that 218 shear strength of sediment that resists shear large range of chemical issues and are well several unique differences among congeners 219 Figure 4. Example produced strong and divergent patterns of identical as possible to keep the numbers of congener vegetation on erosion. The plants of eroded volume invasion. confounding variables minimal. As previous for all experiments will be grown in a over time and profile studies suggested, more mature plants greenhouse to the same level of maturity dune changes using One of the reasons why the congeners of usually have more developed root systems prior to testing to standardize the age of the 3 groups of live Ammophila was selected for the study is and a larger overall biomass that produces plants. These grasses typically grows about vegetation. VO is that both grasses show more similarities positive effect on dune erosion (Figlus, J., 7 cm in 10 days (USDA, 2017) but in a potted initial wave exposure than differences as listed above. Another et.al., 2014). For this reason, all plants that will environment, it maybe less. without any plants. motivation for this study was derived from be used in the experiments will be grown to V1 represents the the concept that when congeners share maturity in the greenhouse before subjection In a wave flume (dimensions: L x W x H = 15m congener group characteristics that produce similar impacts, to wave flume episodes. x 60 cm x 1.3m) with a plunger wave-maker, of Ammophila , their joint invasion will be cumulative (Hacker a test dune made of fine sand material and V2 and V3 for the et.al., 2012). Since both species are grown Both grass species are monocots that have sand volume recorded will be constructed by homogeneous AMAR in their native habitat as efficient dune fibrous root system characterized by a mass hand and subjected to regular wave attack and AMBR groups stabilizer, they belong to similar functional of roots of about equal diameter (Britannica, (Sigren, 2017). Three plant test groups of respectively ( Figlus group. A functional group comprises species 2017). Ammophila has fine fibrous root plants will be exposed to 60 minutes of et.al, 2014). with common response to environmental system indicating typically higher tensile root waves (H= 5 cm. T=0.8 s) at a constant water pressures and similar effects on ecosystem strength ( Sigren, 2017), one of the reasons depth of 18 cm near the wave maker. processes, in this case, to prevent coastal why the congeners were selected for the erosion (Mahdavi, P., et al , 2016). experiment. While AMAR’s root growth Each plant test group will consists of the pattern involves longer vertical rhizomes with following: AMAR and AMBR plants grown in AMAR (Europe native) and AMBR, a native multiple tillers resulting in clumped tussocks pots (dimensions: 10 x 10 x 10 cm) in 1:1 ratio of eastern north US, were found to be closely that capture more sand in the vertical plane, with 6 tillers per pot, pure AMAR, and AMBR related and superficially similar grass species AMBR’s growth pattern involves more lateral plants (both with 6 visible tillers per pot) are that differ substantially in their invading rhizome production with shorter internodes the 3 identified test groups respectively. Plant success but both are effectively utilized in resulting in evenly distributed tillers that density, age, and root stability will be kept as their native habitats for dune stabilization. capture more sand in the horizontal plane identical as possible prior to wave inundation Both grasses can highly modify their habitat (Hacker, S., et.al., 2012). exposure. Figure 3. Laser by creating foredunes, tall ridges of sand scanner cart set on parallel to the shoreline, which intercept If both grasses will be grown together March will be the most preferable month top of wave flume wind-driven sand delivery to the backdune. successfully, predicted increase in sand (Taisce, 2017) to start the greenhouse (Sigren,2017). capture coverage and amounts of fine root propagation, anytime between the months Scope of the study will result to homogeneous root distribution of September- April as deemed most This study investigates the synergistic throughout the substrate and above- appropriate by the researcher or until the impact of live vegetation using congeners ground plant surface area that will enhance entire vegetation test groups are established of Ammophila in a short-term dune erosion the cumulative effects, improve sediment in pots. Clear pots are suggested if available, process induced in a wave flume experiment. cohesiveness ultimately resulting to reduced for ease in root establishment visibility. Then, In the real world, vegetated dune dynamics erosion (Figlus, J., et.al., 2014). In relation each test group will be transplanted into happen on various time scales with multiple to the goals of this study, dune stability if the model dune with 12-18 inches spacing processes involved, hence, the study is limited improved, will minimize coastal erosion. It is (see example Figure 2, previous page) to the hydrodynamic forcing conditions in the therefore appropriate for the sediment to between each potted plant. Transplanted wave flume tests to be conducted. Further be sampled from Galveston, Texas in order grass will be given 10 additional days in the investigations are highly encouraged in a to mimic the actual sandy conditions where dune to allow the plants to acclimate to larger setting that can closely depict the the species are designed to be grown in the the new environment while maintaining the dynamic interactions in both the biotic and future. temperature, water and light conditions for abiotic sandy environment where the two growth prior to the vegetation’s exposure dune stabilizer species thrive if applicable. Methodological Design to wave inundation. The same steps will be This investigation will test the hypothesis that repeated for the remaining plant test groups. The hypothesis to be tested aims to explore propagated congeners of Ammophila will the possibility of propagating two related produce synergistic effect on reducing soil Volume of sediment will be profiled, species of Ammophila in the same dune erosion via a series of laboratory experiments recorded and measured prior to the initial environment and its synergistic effect on involving wave flume and erosion volume wave exposure of each test group. A laser erosion reduction. Aside from maintaining measurement. Preliminary flume tests in a scanner cart in the middle of the flume will the regular wave exposure in the wave flume, small-scale wave flume will be conducted to be mounted (see Figure 4, pevious page) to 220 plant maturity and type of sediment will be get a first impression effect of Ammophila a movable cart to measure dune and beach 221 Figure 5. Growth morphological profile changes (Sigren, Implications of the Study (David, P., et.al, 2017). With increasing of Texas: Processes, Characteristics, and pattern of AMAR and 2017). Profiles extracted every 0.8 sec will be Results of this study will provide new evidence that species introduction that alters Factors in Use. Bureau of Economic Geology. AMBR (Hacker,2012) plotted to represent the eroded volume of insights for coastal managers, engineers, new kind of interactions jointly influencing Geological Circular 77-3. The University of sand that retreated and dune morphological environmental scientists, and biologists the success of introduced population Texas at Austin. changes throughout the experiment (see involved in restoration projects to consider (Mitchell, C., 2006), the two related species Mitchell, C. E., Agrawal, A. A., Bever, J. D., Figure 3 example). propagating dune stabilizer congener species grown might produce cumulative effects. Gilbert, G. S., Hufbauer, R. A.,Klironomos, J. N., in reducing dune erosion. Galveston Bay is Since AMAR and AMBR both function to Maron, J. L., Morris, W. F., Parker, I. M., Power, Limitations of the Study enlarging due to shoreline erosion and net stabilize dunes, this research study may A.G., Seabloom, E. W., Torchin, M. E. and Due to limited time for this study, a wave coastal submergence coastlines are prone provide new insights for further exploration Vázquez, D. P. (2006), Biotic interactions and flume was suggested, however, a movable- to dune erosion (Philip, J., 2015). Another on new growing techniques utilizing plant invasions. Ecology Letters, 9: 726–740. bed wave flume will be highly encouraged to implication of this investigation will be congeners to enhance dune strengths and doi:10.1111/j.1461-0248.2006.00908.x further investigate the free surface elevation beneficial to coastlines that are constantly maintain the defensive role played coastal Philips, Jonathan. (2015). A Sediment Budget for every wave burst, examine shoaling nourished because of its preventive flooding dune systems against erosion. for Galveston Bay. University of Kentucky. characteristics, estimate wave spectra and potential to future coastal community, https://www.researchgate.net/ calculate wave reflection coefficients of the additional habitats for other marine publication/266214082 irregular wave and more intense waves that organisms and aesthetic value of dune References Provoost, Sam, M., Jones, Laurence M., and may simulate actual coastal storm events. vegetation. Moreover, this research supports An Taisce’s Clean Coasts Programme – A Edmondson, Sally E.(2011) “Changes in the soft engineering goals and building with Practical Guide to Marram Grass Planting landscape and vegetation of coastal dunes Another interesting avenue that could nature approaches that incorporate natural Arens, S. M. (1995). Patterns of sand transport in northwest Europe: a review.” Journal of be explored that is highly relevant to this solutions to reduce flood risks in coastal on vegetated foredunes. Geomorphology 17 Coastal Conservation 15.1 (2011): 207-226. experiment is the substrate shear testing communities. (1996) 339-350. Ranwell, D. (1960). Plant associes and among the three plant test groups to Ammophila arenaria. Global Invasive Species sucession cycles of the sand dune and dune determine how the synergistic effect of two From biological standpoint, the basis of this Database. Retrieved May 4,2015. slack vegetation. The Journal of Ecology. congener plant roots contributes to more research was synthesized from Darwin’s Apteker, Rachel. (2008). Invasive Plants of Newborough Warren, Anglesey. cohesive dune sediment. Shear testing of concept that the kind of new interaction, in California Wildland: Ammophila arenaria. Rodriguez-Echeverría,S., Freitas, H., and van vegetated and non-vegetated substrate this case might possibly be a synergistic one, California Invasive Plants Council. Retrieved der Putten, W.H. (2008) Genetic Diversity and samples carried out in the laboratory in gained by an introduced population (AMAR) 2008-09-18. Differentiation of Ammophila arenaria (L.) previous studies indicates that dune plant will depend on its degree of relatedness David, P., Thebault, E., Anneville,O., Duyck,O. Link as Revealed by ISSR Markers. Journal of roots contribute to the mechanical strength to native populations (AMBR). This idea F., Chapuis, E., Loeuille, N. (2017) Impacts of Coastal Research. Volume 24, Issue 1: pp. 122 – of non-cohesive dune sediment (Figlus, et.al., was emphasized in Darwin’s naturalization Invasive Species on Food Webs: A Review 126.doi: http://dx.doi.org/10.2112/06-0668.1 2014). Prior tests conducted revealed that hypothesis which explains that greater of Empirical Data Advances in Ecological Russo, M., Pickart,A., Morse, L., & Young, the substrate was subjected to shear in the invader success for species more closely Research, vol. 56 http://dx.doi.org/10.1016/ R.(1988). Element Stewardship for direction of root growth corresponding to a related to residents, would be expected if bs.aecr.2016.10. Ammophila arenaria. vertical plane (i.e. dune scarp) in a real dune. more closely related species require more Gadgil, R. (2006). Marram Grass-Friend or Sigren, Jacob. (2017). Coastal Dunes and In the same vein, substrate with Ammophila similar abiotic environmental conditions, in Foe?. A Review of the Use of Ammophila Dune Vegetation:Interdisciplinary Research congeners roots with similar levels of this scenario, the sand dune environment arenaria on New Zealand Sand Dunes. on Storm Protection, Erosion and Ecosystem maturity and root densities can be compared (Mitchell, 2006). Invasion success of Coastal Dune Vegetation Network Technical Restoration. Ph.D. Dissertation. Texas A&M to substrates of AMAR and AMBR roots to these congeners that are functionally Bulletin No. 5. University, College Station, TX. determine the impact of root accumulation and genetically related is very promising, Hacker, S., Zarnetske,P.,Seabloom,E., on sediment shear strength. considering all relevant evidences from Ruggiero, P., Mull,J., Gerrity, S., and Jones, C. www.britannica.com/science/fibrous-root- previous studies presented. (2012). Subtle differences in two non-native system A variety of Gulf shoreline features exist congeneric beach grasses significantly affect http://npdc.usda.gov along the Texas coast (McGowen, 1977). Following this line of thought, propagating their colonization, spread and impact. The www.nrcs.usda.gov retrieved May 2017. Variability results from such factors as the two species of Ammophila Nordic Society Oikos. www.gov.mb.ca retrieved May 2017. Pleistocene depositional and erosional simultaneously might produce additive Figlus, J., Sigren, J. M., Armitage, A. R., & Tyler, history, sand availability, climactic conditions, effects in trapping and holding the sediments R. C. (2014). Erosion of vegetated coastal density of other vegetation, direction of that will result to reduced coastal erosion. dunes. Coastal Engineering Proceedings, wave approach, and direction of longshore Decreased rate of erosion overtime will lead 1(34), 20. sediment transport ( McGowen, 1977), to increased dune growth in size, woody Frosini, S., Lardicci, C., & Balestri, E. (2012). which are beyond the scope of this study. In vegetation colonization in the rear dune Global change and response of coastal addition, anthropogenic activities that tend that will later initiate soil formation. Studies dune plants to the combined effects of to tip the balance towards disequilibrium suggested that in order to avoid or limit the increased sand accretion (burial) and nutrient can become agents of destruction that can impacts of invasions, functional diversity availability. PloS one, 7(10), e47561. 222 expedite coastal erosion. might matter more than species diversity McGowen, J. H. (1977). The Gulf Shoreline 223 Image left: Image below: Photo courtesy NSF-PIRE 2017 Case #4 Case study location. Room for the River Rijkswaterstaat Waal at Nijmegen, Beeldbank - Johan The Netherlands. Roerink Aerophoto ROOM FOR THE RIVER #3 Dyke relocation (beeldbank.rws.nl) and river widening O by means of an ancillary channel. NIJMEGEN & WAAL RIVER

This case study examines the Room for the River project in Nijmegen Here are some examples of Research Questions (RQ) that could (but from various perspectives. The goal of the Dutch Room for the not must) serve as a guide to further development. River Program is to increase the storage capacity of the river and its floodplain in order to manage high river flows and decrease water RQ 1: How have the Room for the River program affected the vicinity levels in urban areas. At more than thirty locations in the Netherlands, environmentally? a new approach has been implemented: instead of continuing to RQ 2: What kinds of stakeholders have been involved and what were increase the height and size of the levees, measures are taken to give their roles? the river space to flood safely. Moreover, these measures are designed RQ 3: What should be considered to adopt the Room for the River in such a way that they improve the environmental quality of the initiative in Houston? immediate surroundings. RQ 4: What would be engineering challenges to apply the Room for the River initiative in Houston? Between the cities of Nijmegen and Lent, the Waal River makes a RQ 5: How does the Room for the River program affect ecological sharp bend. The river is very narrow at this point and during extreme resilience? high water levels, this location acts as a bottleneck inhibiting flows and increasing flood vulnerability. The Room for the River project has solved this problem by moving the levee at Lent 350 meters landward. An ancillary channel was dredged in the floodplain to help drain the river during extremely high water. This intervention creates more effective flood protection for the area behind the levee. Relocating the levee and dredging an ancillary channel has created a long island in the river. A unique river park was formed by the combination of the island and the channel. A 1.6 km long slanted quayside forms the new flood control, together with the green banks on the east side.

Although the Room for the River is one successful example of flood management, its widespread use has been challenging due to the different engineering, social, environmental, and governmental issues.

224 225 Figure 1. http://www. Siyu Yu Neighborhoods ruimtevoordewaal. in Nijmegen and nl/en/room-for-the- the location of river-waal; https:// ASSESSING FLOOD VULNERABILITY AND THE NETWORK OF Room for the Waal open-data.nijmegen. Program in the City nl/ ) PLANS IN NIJMEGEN of Nijmegen. (Source: PLAN INTEGRATION FOR THE RESILIENCE SCORECARD

Siyu Yu is a third-year PhD student in the The research questions that are examined regards to the influence of local government Urban and Regional Sciences program are: decisions and the potential to achieve plan in Texas A&M University’s Department of 1. Specifically focusing on the “Room for the implementation (Hollander et al. 1988; Kent Landscape Architecture and Urban Planning. River” initiative, how well-integrated are its 1990). Berke and French (1994) specified that policies throughout the Nijmegen network high quality plans consist of three general of plans? characteristics: The Netherlands is one of the most flood- 2 How does this integration affect hazard - a fact basis that can completely define prone countries on earth. For centuries, the vulnerability at the neighborhood scale? local demands; Dutch addressed this threat by building - clear goals to address the local needs; and - higher and higher dikes to keep waters at Understanding Dutch Planning detailed and executable policies that can bay in a country where 55 percent of housing Growth management and spatial planning fulfill the plan’s goals. is located in areas prone to flooding. While are the dominant planning traditions in Moreover, Baer (1997) distinguished the massive coastal engineering projects have the Netherlands (Van Der Valk 2002). five evaluation stages of the planning largely eliminated the threat of flooding The Dutch system of spatial planning and process: plan assessment, testing, plan from the sea, significant dangers remain with comprehensive environmental planning critique, comparative study and professional respect to riverine flooding. The Netherlands are built upon the consensus of political plan evaluation, and post-implementation was once again confronted with near-floods institutions and advisory sectors consisting evaluation. These studies make up the in 1993 and 1995, due to the increased river of experts and stakeholders (Horst 1996). foundation of the field of individual-type plan discharges caused by large volumes of melt Moreover, spatial planning is rooted in all quality evaluation, but there are still some and rainwater from upstream regions. In three tiers of administrative systems: central gaps in evaluating the consistency between order to prevent flooding in the near- and government, provincial government, and multiple local plans. long-term, the Dutch government decided municipal government. Research gains a deep that a new approach was needed: instead of understanding of the drivers of spatial and The development of an “information system continuing to increase the height and size environmental planning in the Netherlands of plans” (ISoP) of the dikes, the Netherlands is now making by taking account of physical, social, culture, Planners should work consistently with more room for water. and economic factors (Horst 1996; Van Der multiple plans and different interest groups Valk 2002). Van Der Valk (2002) pointed out (Branch 1971; Hopkins, 2001a, b; Hopkins The main objectives of this program are that multiple land use had been adopted as et al. 2005). To achieve this goal, Finn et al. to give the river more room to be able to the strategy to fight against urban sprawl, (2007) created an information system of manage higher water levels and to improve improve land use efficiency and prevent plans (ISoP) to facilitate land use planners the overall environmental quality in the river the national ecological network from accessing and using multiple plans to make region. These measures taken along the rivers fragmenting. In terms of dealing with flooding reliable decisions. The ISoP tool includes IJssel, Lek, Maas and Waal are known as issues, especially with respect to integrating transportation plans, strategic plans for water “Room for the River”. The City of Nijmegen is water management and spatial planning, resource management, comprehensive plans, vulnerable to flooding in a changing climate, Dutch strategies are moving from regulation green infrastructure visions, county zoning and the project in Nijmegen is the biggest to strategy planning and planning for a larger ordinances, historic preservation ordinances, and most awe-inspiring of the national social-cultural scale (Woltjer & Al 2007). solid waste management, regional framework “Room for the River” program. It remains plans, etc. This method was hugely innovative unclear that how and to what degree “Room Enhancing Plan Quality for two reasons: for the River” programs influence ecological Plan evaluation is an efficient and feasible - it gives users a clear picture of the hotspots impacts and flood vulnerability in the city of way to define plan quality and address where overlapping plans conflict and Nijmegen. This study explores the influence planning as a legitimate policy-making cooperate; of plan integration on ecological resilience to process. Several scholars have defined the - it allows users to address the gaps and 226 flooding. characteristics of high quality plans with conflicts in the entire planning system of 227 Table 1. FACTOR DOMINANT VARIABLE documents. This information is useful for impact of land policies on land development perspective of community recovery capacity Dimensions of all interest groups to have a better idea in the 100- year floodplains of North Carolina. perspective, since local communities can Social Vulnerability. Personal Wealth Per capita income of their communities. The development of Various Florida studies also applied building sometimes survive extreme natural events (Source: Cutter et Age Median age ISoP allows planners to evaluate multiple tax values to determine the impact of land with minimal population or property loss, al. 2003) Density of the built environment No. commercial establishments/mi2 plans in the whole regional planning policies in the coastal hazard zones of the build more diverse populations, and foster Single-sector economic dependence % employed in extractive industries system, however it cannot identify the south Florida area (NOAA, 2015; Southeast economic revitalization (Mileti 1999; Berke positive or negative effects plans have on Florida Regional Compact, 2012). Similarly, Shi and Campanella 2006). Some scholars Housing stock and tenancy % housing units that are mobile homes hazard vulnerability. & Yu (2014) employed land value to assess interpret resilience in terms of social systems, Race—African American % African American the value of various resources and services in defining it as the propensity of certain social Ethnicity— Hispanic % Hispanic Plan integration for resilience scorecard the urban environment of Shenzhen, China. units to move toward mitigation, resistance Ethnicity—Native American % Native American Most communities have a comprehensive Prior studies have thus established precedent of natural hazards, and recovery from Race—Asian % Asian plan, local mitigation plan, open space plan, for building tax values to be used as a such impacts, as well as reducing future and transportation plan. Unfortunately, measure for physical vulnerability. vulnerability through adaptive strategies Occupation % employed in service occupations these plans do not integrate and coordinate (Peacock et. al. 2008; Maguire & Hagan 2007; Infrastructure dependence % employed in transportation, communication, and public utilities well. The local mitigation plan should be - Social vulnerability Bruneau et al 2003). integrated with other local plans. In addition, Cutter et al. (2003) applied 1990 county- how well multiple and independent planning level socioeconomic and demographic data - Resilience from the Field of Ecology efforts are integrated can significantly to build up an index of social vulnerability to There are various approaches to impact future community vulnerability to hazards, which is called Social Vulnerability understanding resilience in the field of Table 2. DOMAIN SOCIAL VULNERABILITY INDICATORS hazards. Berke et al. (2012) proposed that Index (SoVI). They used 11 composite factors ecology. Holling (1973) identified it as an Indicators that the federal Disaster Mitigation Act (DMA) to quantify social vulnerability at county level, ecosystem’s ability to deal with change. Comprise Social Household composition % persons 65 years of age or older mandate the integration of mitigation including personal wealth, age, density of the Pimm (1984) viewed ecological resilience Vulnerability % persons 14 years of age or younger plans with land use planning and climate built environment, single-sector economic as the speed at which a system returns to (Source: Data from Socioeconomic status % households under or around minimum incomei2 change adaptation. Berke et al. (2015) dependence, housing stock and tenancy, its original state after a disturbance. Several Centraal Bureau General assistance benefits (per 1000 households) designed a resilience scorecard that consists race (African American, Asian), ethnicity, scholars understand it as an ecosystem’s voor de Statistiek of geospatial indicators to evaluate the occupation and infrastructure dependence. capacity to absorb perturbation (Holling (http://www. Average per capita income networks of plans (e.g. land use plans, The dominant variable will be explained in et al. 1995; Lebel et al. 2006; Walker & Salt weetmeer.nl/buurt/ % non-Western immigrants mitigation plans, infrastructure plans, etc.) Table 1. The unit of analysis of their study is 2006). In particular, Folke et al. (2002) Nijmegen/0268) Minority status % multi-family structures and hazard vulnerability in response to calls counties. interpreted resilience from the perspective and indicator names Housing/transportation % homes built before 2000 for better integration of planning. They of socioecological systems, manifested adapted from ACS Number of vehicles per household tested the applicability of the indicators Recognizing Resilience by three elements: absorption capacity, 2006–2010 (5 year on a demonstration community that was The Economics of Ecosystems and self-organization capacity, and adaptation estimates) from the % rentals vulnerable to coastal flooding and sea level Biodiversity (TEEB) reports state that capacity. C.S. Holling introduced resilience to U.S. Census Bureau % housing units occupied rise. This study aimed to address the crucial ecosystems and biodiversity affect our the ecological world in 1973 to shed light on (2015). issue of plan integration, and to explain how well-being, the economy, and the survival the complexity and non-linear dynamics in planning can be improved to respond to from natural hazards. Resilience to flood ecosystems. In ecological systems, resilience the growing losses posed by hazard events, disturbances depends on a healthy is rooted in essential functional groups and inform the public and decision makers, and ecosystem. Increasing amounts of evidence the accumulation of resources for recovery. Table 3. TIERS OF ADMINISTRATIVE SYSTEMS PLANS highlight needed changes in planning and suggest that natural habitats - such as Network of Plans policy instruments (Berke et al. 2015). wetlands, dunes, sea grasses, coral reefs, and Methods in the City of National Delta plan Room for the River (1) barrier islands- can reduce the chronic risk Case selection: The city of Nijmegen is Nijmegen Provincial Structure vision (2) Assessing Vulnerability of coastal flooding due to rises in sea level selected for several reasons, including its (Source: Plan Nature policy (3) - Physical vulnerability (Shepard et al. 2011). location situated on the Waal River, which documents). Water policy (province, water authority) (4) Physical characteristics consist of structures, makes it naturally exposed to riverine infrastructure, and natural environments - Resilience from the Field of Disasters and flooding. Also the project in Nijmegen is Local Comprehensive plan | Structure vision (5) (Masterson et al. 2014). Berke et al. (2015) Hazards the biggest and most awe-inspiring of the Master plan (6) utilized land parcel data from the city of Diverse interpretations of resilience can be national “Room for the River” program. Land use plan of Lent (7) Washington’s 2010 building tax values found in the field of disasters and hazards. Nijmegen is a municipality and a city in the Land use plan of Oosterhout (8) (U.S. dollars per square foot) to determine Various studies define resilience as the Dutch province of Gelderland with a 2011 Land use plan of Haven- and industrieterrein (9) physical vulnerability. This is consistent with measure of a system’s capacity to obtain, population of 164,223 (Figure 1). The city of the methodology of other studies that have withstand, and recover from a hazard event Nijmegen’s “Room for the River” plan has Land use plan of Biezen (10) focused on the impact of land use policies on (Timmerman 1981; Wildavsky 1991; Li & received the “Excellence on the Waterfront Land use plan of Benedenstad (11) land development. Patterson & Doyle (2009) Buckle 1999; Klein et al. 2003). Moreover, Honor Award 2011” from the Washington, 228 Land use plan of Ooyse Schependom (12) used building tax values to measure the several studies identify resilience from the D.C.-based Waterfront Center for combining 229 income and vulnerability. Higher per capita incomes correlated with lower vulnerability.

After ranking these factors, they then calculated a percentile rank for each block group among the indicators, employing a “flag” score to identify high vulnerability populations (Flanagan et al. 2011). Berke et al. (2015) applied 86% or higher rank per block group as the flag counts to identify areas that had vulnerable populations in 7 census blocks groups in the city of Washington. Census block groups served as the unit of analysis for their study.

3. Create resilience scorecards for hazard and ecological impact A specified hazard and ecological resilience scorecard should be generated for each of the 12 plan documents in Nijmegen’s network of plans at national, provincial and local level created between 2007 and 2016 (Table 3 see previous page). Every land policy district should be assigned a score of ‘+1’, ‘-1’, or ‘0’ for every land use policy. ‘+1’ indicates that the policy is expected to positively affect hazard and ecological vulnerability, while ‘-1’ indicates a negative effect. ‘0’ indicates that the land use policy does not affect hazard and ecological vulnerability in the land policy district.

Results - Vulnerability assessment According to the vulnerability assessment, there exist greater variation in the embanked flood safety with construction of a riverside Methodology are 44 planning districts (neighborhoods) district located within hazard zones. This vulnerability: household composition, neighborhoods than in the unembanked park with the close involvement of the local Evaluating plan integration and hazard in the city of Nijmegen. The hazard zones study measures social vulnerability using 11 socioeconomic status, minority status, neighborhoods within the City of Nijmegen. community. The twin goal of “the room for vulnerability in Nijmegen is a three-phase in the city of Nijmegen include both the out of the 15 indicators from the CDC Social and housing and transportation. There the Waal” program is process. embanked and unembanked areas.. And Vulnerability Index. Indicators comprise are 15 variables representing the four - Physical Vulnerability 1. To protect the City of Nijmegen from future the unit of analysis of this study is the four domains of social vulnerability: domains selected based on the hazards Results show that there is variation in floods; and 1. Delineate planning districts and hazard hazard zones within the 44 planning household composition, socioeconomic vulnerability literature. The index uses data physical vulnerability in the City of Nijmegen, 2. To enhance the urban spatial quality. zones districts (Neighborhoods). status, minority status, and housing & from the 2010 U.S. Census at the census with mean housing value (WOZ) ranging In order to spatially analyze both the transportation (Table 2, see previous page). tract and block group levels (Flanagan from €131,000 to € 480,000 (Figure 3a, Specifically, first, Nijmegen is not simply vulnerability measures and the applicable 2. Determine vulnerability It applies 75% or higher rank per district, as et al. 2011). Berke et al. (2015) measured next page). Hunnerberg, Kwakkenberg, and raising or strengthening its dikes. Instead, it plan policies, the city of Nijmegen can be Physical and social vulnerability scores are the flag counts to identify high vulnerability social vulnerability using 12 out of the 15 Ressen are the most physically vulnerable is moving some dikes back from the river, divided into sub-jurisdictional areas known determined using mean property tax values populations in 44 planning districts indicators from the CDC Social Vulnerability planning districts (neighborhoods). The essentially creating a much wider floodplain, as ‘Land Policy Districts (Neighborhoods)’. (Woningwaarde) and variables from a (neighborhoods) in the city of Nijmegen. Index. From there, they also ranked each least vulnerable neighborhoods include which giving future floodwaters more room Each applicable policy affects the social vulnerability index computed using a indicator from highest to lowest across all Aldenhof, Hatert, Lankforst, Malvert, Meijhorst, to flow without threatening the city. Second, vulnerability of the population (or the ‘flag count’ indexing procedure developed The U.S. Center for Disease Control (CDC) census block groups in the case study area, Neerbosch-Oost, Tolhuis, and Zwanenveid. all engineering work is creating more than infrastructure, or the ecology, etc.) in each by the U.S. Centers for Disease Control developed its own Social Vulnerability with the exception of per capita income Most of the six unembanked neighborhoods flood control; they also provide space for district differently, depending on the land (Flanagan et al. 2011). Vulnerability scores Index for Disaster Management (SVI). The which was ranked from lowest to highest are in the moderate vulnerability range. 230 parks and nature areas. use characteristics in that district. There are derived for the area of each planning SVI uses four domains to assess social due to the negative relationship between Biezen is the least physically vulnerable 231 Figure 3. neighborhood within the unembanked area, Multiple land use policies propose to fight References (Left) 3a. Physical while Haven-en industrieterrein has the against urban sprawl, improve land use Baer, W. C. (1997). General plan evaluation vulnerability highest physical vulnerability among the efficiency and prevent the national ecological criteria: An approach to making better WOZ index by unembanked neighborhoods (Figure 4). network from fragmenting in the network of plans. Journal of the American Planning planning district plans of Nijmegen, which corresponds to the Association, 63(3), 329–45. Doi: (neighborhood) - Social Vulnerability observations of Van Der Valk (2002). Results 10.1080/01944369708975926 hazard zone in As for social vulnerability, flag scores show show that policies aimed at increasing Berke, P. R., & Campanella, T. J. (2006). Nijmegen that Meijhorst (9 out of 11 flags) and Aldenhof density and improving land use efficiency Planning for postdisaster resiliency. The (8 out of 11) are the most socially vulnerable in hazard areas increases the physical Annals of the American Academy of Political (Right) 3b. Social neighborhoods. Malvert, Hatert, Neerbosch- vulnerability of the densified neighborhoods. and Social Science, 604(1), 192-207. vulnerability ‘flag Oost, Nije Veld, and Wolfskuil receive 5-7 According to social vulnerability, even though Berke, Philip and Steven French. 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(1996). The Low Sky: Planning, 125290-297. Understanding the Dutch. Scriptum Books, Southeast Florida Regional Compact. Schiedam. Kent, T. J. (1990). The Urban (2012). Analysis of southeast Florida sea General Plan. Chicago: American Planning level rise. Retrieved from www.southeastfl Association. oridaclimatecompact.org//wp-content/ 234 Klein, R. J., Nicholls, R. J., & Thomalla, F. uploads/2014/09/vulnerability- assessment. 235 Figure 1 (top). Figure 2 (bottom). in Lent, Nijmegen. Madison Bennett Room for the River Looking up The far right was Nijmegen, Lent, #roomfortheriver on one of the few artist Impression. social media, these negative posts; this A SOCIAL PERSPECTIVE ON THE SUCCESS OF (Image courtesy of are some of the inspired my research Ruimte voor de rivier tweets commenting question. ROOM FOR THE RIVER projectbureau) on the R4R project THE STORY OF LENT, NIJMEGEN, THE NETHERLANDS

Madison is a fourth year architecture student dike running along this bottom curve of land The question I sought to answer this summer at Texas A&M College Station. with some room for flood plains. The project is this: From a social perspective, was the included pushing this dike inland 300 meters Room for the River Project in Nijmegen and dredging a channel for the river to divert successful and why? In order to answer As a large portion of the Netherlands is to, creating a small island and more floodplain this question I have defined success in this below sea level, flooding has the potential area. The goal is to allow the river more room specific context. For this particular research, to be serious issue and must be addressed to flood and provide safety to the inhabitants I am defining success as fulfilling the wishes and prevented in all areas of the country. of Nijmegen and Lent. Spatial Quality was and taking into consideration the concerns of This summer I had the chance to visit the also a main goal of this project and was the residents involved in this project. Netherlands and travel all over, witnessing achieved by creating area for recreation and these flood prevention methods firsthand. outdoor activity along the river and new The importance of this research is how One of the biggest flood prevention island space. Through this redevelopment of it is applied to other projects in other programs in the country currently is the the area, many families had to be relocated locations. Our team goal was to build a set Room for the River Project. The Project is a out of the existing area to make room for of knowledge and lessons from the Room for nation-wide initiative with 40 riverside sites the new dike, channel, and floodplain. This the Waal River Project that other cities, such all across the country. At each site various area is a small town with years of tradition as Houston Texas, may refer to. Our research methods are being used to control and and culture and families that have lived there explores different aspects of the project in prevent flooding, including dike relocation for generations. A change like this would be Nijmegen and could be used in application and reinforcement, flood plain evacuation, expected to be a huge shock for the area to a larger-scale urban flood mitigation and river widening to name a few. In all the causing controversy and varying opinions. project. My personal goal with my research sites, the two main goals are flooding safety was to learn what resistance from the public and spatial quality. As I first began looking into this project I we could expect to encounter if a similar noticed there was a lot of positive marketing project was attempted Houston. By looking This summer I worked with a team of two and “propaganda” like advertising. The at what was successful or unsuccessful about other researchers looking at the impact of plan for the area appeared smart and this project from the beginning planning, to the Room for the River Project. My team’s like it would bring about positive change. construction and execution, and final use, a specific site within the project is in the Looking up #roomfortheriver on social broader understanding of public values and eastern town of Nijmegen with the small media yielded even more positive reports, reactions could be used to apply to projects nearby community of Lent. The methods with people shown enjoying the area and in the future and make them stronger from used in this particular area were true to the praising the government for taking a more their very inception. name of the entire project and worked to environmentally conscious approach to flood give the river more room through widening, control. However, one post on Instagram In order to conduct this research I relied dike relocation and reinforcement, and caught my eye for its negative perspective on multiple methods and resources of redevelopment in the area. In the particular on the project. It showed a Mr. Hank Jacobs in information. While in the Netherlands I area of Nijmegen, the Waal River forms a his bar and claimed that the project isolated sought out expert opinion, local opinion, large curve with Lent nestled in the concave him from his customers. This post sparked personal investigation, and observation of side. The width of the river decreases a curiosity in me to see how the changes the area. I planned to find out what planners significantly as it curves around Lent, from had affected the residents of the area. It and leaders of the project see as its most roughly 1000 to 1500 meters wide on led me to wonder if all the expert opinions successful attributes as well as how the either side to about 400 meter wide at its and information I was finding on the project process, planning, design, and construction narrowest point in the middle. This narrowing were glossing over some of the negative provided and added benefit to the area. My of the river creates a severe bottleneck and consequences the people of the area were hope was to speak with locals and people is the main reason for flooding under heavy facing in the wake of the changes. This directly affected by the relocating and 236 rain and storms. The area previously had a inspired my question to drive my research. disruption and hear what was positive and 237 Figures 3 & 4 (top). Figures 5 & 6, negative throughout the entire timeline of out to the residents and she was available to following year gave more insight on the Cafe De Zon at Lent, (bottom). the project. By walking the area myself I them throughout the entire process, which situation and stated that when the plan was exterior and interior. Cafe Biljart Waalzicht planned to assess the design of the area and she says they utilized. When I asked about first announced, there was definitely protest at Lent, exterior and observe how people were using it. I planned the people’s main concerns and ideas during from the public. The people did not trust interior. to compare my personal experience in the the inception of the project, Andrea stated the statistics and what the government was area with what the online propaganda and that the people respected and cherished the telling them and did not believe there were planners were deeming its most attractive water due to its importance to the town’s real, immediate danger of flooding. They attributes. heritage, however, their main concern was were concerned that the plan did not address safety and their property value. At the seepage water along with the relocation of My first encounter with the area was on the residents’ request a seepage screen was the dike, and feeling that their voice was not day our group traveled to Nijmegen and added to the design of the new dike. Because being heard, the community formed a group had the opportunity to hear a presentation the area has been quaint and calm for years, entitled GeWa to represent themselves. on the project by Andrea Voskens, the the new bridges were designed to only allow GeWa formed an alternate plan to be director and resource for the residents of cars onto the island from one direction. implemented in the area to address flooding the area to contact throughout the entirety With no connection from the south the issues in the future if it became needed. This of the project. Andrea presented us with a amount of cars and noise on the island can plan was called the “Lentse Warande” and timeline of the design and planning stages remain minimum. Even with this restrained involved moving the dike in 50 years if it was all the way through the construction and access the new development has brought needed at that time. Members also donated finished product. Andrea gave us statistics more activity and people to the area. The thousands of dollars to show they had the and many of the “numbers” of the project environment is more lively now with visitors potential to go to court, and should be taken and recounted some of the concerns and and recreation in the water. Many older seriously. The plan was well thought out and interactions of the local residents. Coming people (over 65) on the island aren’t as fond passed the environmental impact report, but within budget and taking only three years of the noise and people coming, though, and it was voted down in 2006. Although the plan and three months to complete (under the Andrea predicts they might not stay in the would not come to fruition, the people finally estimated four years) were two of the things area for very long. The one negative aspect felt that they were being listened to. They she names as the projects strengths. With of the design Andrea mentioned was the little gained awareness and the project gained the careful bridge design, traffic flow was to no accessibility. The new pathways are not quality by taking into account the people’s not halted during construction and provided easily navigable for wheelchairs and could ideas. The new walkway along the river is minimum disruption to the community also contribute to the older generation of now named the “Lentse Warande” and shows which she saw as another success of its inhabitants moving away. how the people in the area now have a sense execution. The end result add three new of pride and ownership over the project. bridges to the area and lowered the river by As I sought to find more information on 34 centimeters. 40 trees were replaced, two the resident’s perspective throughout the While in the Netherlands I was able to visit of the 50 demolished houses were rebuilt on project, the best resource I found was a the site two times, once with our entire the island, and one historical building was record of the community’s meeting minutes group and the second on my own. The first completely relocated in order to preserve it. from December 2014 and a relevant article experience was during very cold, windy In the archeological excavation of the area, dating December 2015. In the meeting, a weather that made it unpleasant to be many WWII and historical artifacts were local elderman (community representative) outside. Since there were very few people found in the riverbed and are now on display came to speak with the residents about what out in this weather I took this time to pay along the riverside’s walkway. While it took was happening with the Room for the River close attention to the design of the area and people a while to come together and get Project and how it would affect them. At this the experience of walking it. Our group was on board with the project, Andrea views the point in time it seemed that the residents dropped off on one side of the new bridge end result as being very successful because felt very left in the dark about what was and walked across it to the “island” that was the relocated families were generously happening with the project. The government created from the newly dredged channel. The compensated and were able to move away made promises to preserve the sense of area was wide and open and offered views of with a fresh start that they never would have identity and history in Lent, but it was unclear the water, greenery, and nearby homes from received otherwise. No one sued or halted at that time if they would honor and carry every vantage point. The design of the bridge construction and everyone cooperated when out these promises. The community felt was spacious and allowed bikes, cars, and it was finally time to vacate the area (which their questions about local businesses, the walkers to cross simultaneously and safely was not the case for the project in other rowing team, etc were not being answered. with three different sectioned pathways. sites), even swapping houses and working This information led me to believe that the Our group spent the walk crossing back and together to move in waves, and reusing negative aspects of this project were being forth with the lower connected pathways to pieces and parts of the demolished homes. skimmed over and that some resistance see each side of the river that was lined with 238 Andrea’s personal phone number was given might have occurred. The article from the clean, new paving giving space for seating 239 Figure 7. Figure 8. Figure 9. (All photos in however, the route of the walk was changed school itself is a positive addition to the area, Sources Bike path along the The same location on The bridge over the Figures 3-9 courtesy and no longer runs along the road between it was built on a very narrow set of roads Waal river bypass a sunny day during river bypass, with of the author and the two cafes. According to these men, that has caused bad traffic. The locals are Interviews at Lent, at the my second visit, an under pass for with consent of the this is one of the main reasons business now being asked to attend programs on * Professional experts Room for the River looking the other pedestrians, so they people portrayed.) has declined and is Mr. Jacobs’s biggest safer driving, even though this problem was Mrs. Andrea Voskens, senior adviseur project location. way along the trees; can walk and bike on complaint over the Room for the River caused in the beginning by poor site choice. economische zaken – citymarketing, Threathening cold river bypass at right. both sides. Project. In their opinion, the relocation of The woman expressed that it was frustrating personal conversation, June 6, 2017 weather view during families and houses was very unfortunate, but to be inconvenienced by a problem made my first visit. the river project was necessary for the safety from poor planning and something meant * Local experts of the area. They echoed a few points that to “improve” the area. While the project in Mr. Jacobs (owner of Café de Zon) , Andrea had made during our presentation, Nijmegen also had accessibility faults, it personal communication, June 13, 2017 saying many people used the relocation seems to have much more pride and support Owner and locals at Café Biljart, as a fresh start and were compensated from the people now using it. personal communication, June 13, 2017 generously from the government. When I Local lady on the train, personal asked if the area was really being used by After the presentation with Andrea, my communication, June 13, 2017 the local people as the planners intended, own trips to the area, and conversations they all agreed that on sunny days the place with people experiencing the Room for the Other resources was full of people swimming, tanning, and River Project firsthand, I have concluded - Community Meeting Minutes of Dec. 2014 participating in recreation on the water and that the project executed in Nijmegen was and Article from Dec. 2015 (provided and the shore. Although the redeveloped land and is successful. The logistical merits of translated from Dutch by Bee) is now somewhat expensive (due to the budget, time, and minimal disruption to the - Website Ruimte Voor De Rivier, hefty compensation the original residents neighborhood during construction show www.ruimtevoorderivier.nl/english received), the area has seen a lot of growth that the design was well thought out and - Website Vierdaagse Home, and young families with children have been executed according to plan. Oftentimes www.4daagse.nl/en/ moving to the area. the public’s largest complaint with a new - Social media - Twitter development is how it inconveniences them @cementley, March 23, 2016, The last local I was able to talk to was a personally, and Room for the River sought https://www.instagram.com/p/BDTuwSniB woman on the train ride from Nijmegen back to minimize that. While it seems that the O2/?hl=en&tagged=roomfortheriver to Rotterdam. I struck up a conversation planners, directors, and marketers of the with her about what she was knitting project may have glossed over some of the and eventually we began discussing the negative aspects along the way, in the end Room for the River Project. She lived near the people felt like they were heard and had another site of the project, between Dieren an influence in the design of the project and Brumman, and was able to give me a that was to become their new surroundings. perspective unlimited to just the Nijmegen Evident in the added seepage screen, site. From her description, I believe the site the planners truly took into account the and different activity along the channel. sitting with a book, a mother walking her told me the café had been there since 1860, she was referring to was the dike relocation in resident’s concerns and ideas, took action, Once on the other side, the island had one baby in a carriage, and a few dog walkers and that the river expansion had taken away Cortenoever. In her area, the dike was pushed and incorporated them into the design. Trees, main road leading through it. There was open out for the evening. The area was very calm his customers. In my twenty to thirty minutes back away from the Issel River and the old history, artifacts, and the sense of community grassy space, a mix of old and new houses, and it made for a peaceful, quiet atmosphere. there with my cappuccino and weak attempts dike was turned into a bike path with holes was preserved and maintained and works to and two cafes that have been located there I approached a few people along the path at Dutch, one other customer came in for a to allow water through. The affected people blend the old heritage of the place with the for many years. Café Biljart, the spot of our to ask their opinion of the project and the beer. He seemed to be a regular and chatted at this site were farmers, and while some new design and added features. The goals of presentation with Andrea Voskens, changes that had been made, but wasn’t with Mr. Jacobs for a while before leaving. relocated to land behind the new dike, others safety and spatial quality were seen through able to find anyone who spoke English left completely. Her biggest complaint about until the end and realized in the final product. On the day I visited the area again on my unfortunately. I made my way across the Across the street at Café Biljart, I was able the redevelopment was that the hilly paths Ruimte voor de rivier was een success! own, the weather was much more enjoyable. bridge, through the town, and stopped in to chat with the owner and three local men were not taken into consideration. She has A Tuesday evening around 4 pm, the sky was each of the café’s to see if the owners would for about an hour. They told me about the a very difficult time pushing her grandson cloudy and the air cool, but my walk from the offer up any experiences or opinions on the “Vierdaagse,” a large local event in July. in a baby carriage up them and cannot train station to the bridge was pleasant and Room for the River Project. Vierdaagse includes a four day walk through imagine how it would be pushing an adult I passed charming historic architecture and In Café de Zon, I met the owner Mr. Jacobs, the area and draws crowds of thousands in a wheelchair. This complaint corresponds too many bikers to count. As I approached who lives right above his establishment. of people (2017 had 47,000 registered with Andrea’s point about inaccessibility for the area this time I noticed people swimming As he spoke no English and I no Dutch, we participants.) This event used to bring the elderly in the Nijmegen site. One other in the channel and spending time by the communicated with a few words I was able in many customers to both Café de Zon negative affect she shared with me was 240 water. There were friend chatting, a woman to convey through an app on my phone. He and Café Biljart. After the river expansion the construction of a new school. While the 241 Figure 1. George Barrow 1953 Flood disaster in The Netherlands at Goeree Overflakkee ROOM FOR THE RIVER WAAL: COMPARING HOUSTONIAN (Image courtesy of Rijkswaterstaat AND DUTCH LAND USE PLANNING Beeldbank)

George is an undergraduate studying Civil illustrate important differences between the standard. The Delta Initiative had a number and Environmental Engineering at Rice two of them, which can have wide-ranging of components, such as a revamping of the University. effects on urban form and flood resilience. country’s dikes, damming and diverting rivers, and the construction of the Maeslant Barrier, Background a massive gate that would protect the Port of Abstract Nijmegen is a city in the southeast of The Rotterdam from storm surge. Land-use planning, generally, is the practice Netherlands, built along the banks of the of a governing body deciding what can or Waal River. The Waal is one of the branches The Delta Initiative also included the Room cannot be built in an area. Every country, of the Rhine, one of the major rivers of central for the River program, which was the national and to a lesser extent, city, takes a unique Europe. Nijmegen is the oldest city in The initiative that includes the specific project approach to this process. The Netherlands Netherlands, founded in 5 A.D. For centuries covered by this paper. While the Rotterdam is well-known for its land-use planning it made its name first as a military stronghold barrier and the coastal dikes were meant methods, which have led to world-famous along the river, and then as a trading outpost, to defend The Netherlands from coastal results in bikeability and flood resilience, charging tolls on ships traveling up the river flooding, Room for the River was meant to amongst other achievements. These south into Germany, the border of which is address the increased river flows coming methods are also well known for being only a few kilometers away. from the European continent, which led to very regimented and highly restrictive. In riverine flooding. These river flows have been the United States, on the other hand, the The city’s relationship with the river has increasing due to large storms in Germany, governing bodies tend to hold much less always been somewhat tumultuous. Due attributed to climate change. Room for the power in mandating specific uses, although to occasional high water from heavy rains River (RFTR) planned to address this new this varies from municipality to municipality. in Germany, crossing the river remained riverine flooding threat by widening the Houston, Texas, specifically, stands out as treacherous, leading to strong geographic country’s rivers in strategic locations to a particularly loosely regulating example. separation between the two banks. The city reduce flood risk in the rivers’ choke points. Houston, famous for its lack of a zoning of Nijmegen grew entirely on the southern This widening of the riverbed would allow ordinance, has developed its own approach bank, while the northern bank remained rural, for a wider flow cross section, and therefore to planning. This approach accomplishes known as the village of Lent. As Nijmegen lower peak water levels in flood events. many of the same ends that a typical grew, it began to look northward as a region American city achieves, but through a totally of possible expansion (Lenis, 2017). One such choke point where the RFTR different legal framework, and to a lesser program called for river widening was in extent, with a somewhat lighter regulatory In 1953 The Netherlands was hit by Nijmegen, where the River Waal takes a sharp touch. devastating flooding when a large storm bend and narrows somewhat. In flood events, arrived from the North Sea. The storm the river would tend to cut the corner and To illustrate the Dutch planning method brought a large surge, which raised coastal flood Lent on the northern banks, and in 1993 and contrast it with the American methods, water levels to 4.55 meters above normal. and 1995 it overtopped its southern bank this paper selects Houston as a particularly These high oceanic water levels led to the and flooded Nijmegen proper, leading to the contrasting method. As a particular case failure of 89 dikes, which cause the flooding evacuation of around 250,000 people. The study useful for illustrating Dutch planning of much of The Netherlands, and the deaths national government offered funding for the practices, this paper will be examining the of almost two thousand people. After this implementation of this project; however, the Room for the River Waal project in Nijmegen, pivotal event, the Dutch government moved national government left the implementation The Netherlands. This project was a local quickly to implement the Delta Works, a plan of this project up to the local municipal implementation of a national-level initiative first hatched in 1936, but slow to launch due government of Nijmegen (Voskes, 2017). This to reduce flood risk in riverside settlements in to World War 2 and a lack of urgency — at approach to project planning allowed the The Netherlands. Comparing Dutch practice the time. The Delta Works had the goal of municipal government to consider its own 242 with Houston planning approaches will minimizing flood risk to a drastically higher goals, which could be implemented into the 243 Figure 2. solution while still receiving national project The final design (visible in Figure 2 and now A comparison of land use planning The final design of funding. The details of this arrangement are built) consists of an auxiliary river channel approaches Room for the River, explained below. dredged through the southern tip of Lent Houston has a well-known reputation when Nijmegen. (Image by (the village on the northern shore), which it comes to urban planning. It is popularly H+N+S Landschaps Methodology created a new island out of what used to known as the only major city in the United architecten). To achieve the goals set out in the abstract, be this tip. A few buildings were left on the States without zoning. Legally, this is true multiple site visits and interviews were carried island, but it is mostly pasture, meant to be — there is even a letter, re-signed by the out, in addition to more traditional research a river park. The dike on the northern shore mayor each year, on the Houston planning methods. On June 6, 2017, the author, along of the river was moved back to incorporate website saying so. But effectively, Houston with other NSF PIRE participants, attended a this second river channel into the riverbed has a planning system that looks a lot like lecture summarizing the RFTR project given area. Three new bridges were constructed, traditional zoning, just without the name. by Andrea Voskes, who was in charge of as well as a new quay, inspired by the quay This begs the question: to what extent is public engagement for the RFTR project in in Orléans, France, meant to better connect Houston’s planning framework truly unique? Nijmegen. In addition to the lecture recieved residents with the water and be a space for on this date, this was also the first in-person gathering and festivities. Zoning ordinances spiked in popularity visit to the project site. The PIRE research across America after New York passed its group received an informative tour of the The municipality’s primary goal for the version in 1916. Within ten years, more than remaining part of Lent on the new island of RFTR project was to turn the primarily flood half of the U.S. population was governed Veur-Lent, the island park, as well as the new control-oriented project into a project that by zoning ordinances. Originally, zoning bridges. would help better connect the two sides of served to establish different areas (zones) the river. This was achieved through a few designated for different purposes within the The smaller research team studying the different aspects of the final design. The three context of the city: an area for residences, Nijmegen site in particular also carried out bridges better connect the transportation an area for commercial properties, an area a second visit to Nijmegen, during which infrastructure of the two sides, helping shift for manufacturing, etc. This is the core of time, accompanied by Dr. Nikki Brand of the effective center of the city northward. The zoning, and for the remainder of this paper TU Delft, the team interviewed Matthijs new quay was built on the northern shore of I will refer to it as the land-use map. This is Lenis. Mr. Lenis was one of the key land-use the new river channel, which can help bring meant to reduce confusion, as zoning quickly planners involved with the RFTR project’s residents of the southern shore there when grew to become something much more than implementation in Nijmegen, and is also events are programmed for this new space. just the land-use map. “Modern zoning codes in continuing involvement with some of can span hundreds of pages and dictate the planned developments surrounding The new channel itself also functions as an everything from whether you can own a the project site. Through this key contact, attraction for southern shore residents. Before chicken to whether you can hang laundry testimony about the project planning process the project, the river featured dangerous out to dry” (Gardner, 2017). American zoning and mindset was received, as well as land-use currents and high boat traffic due to its status codes are now comprehensive documents maps from before and after the RFTR project. as a shipping corridor, while the new channel that feature heaps of regulations on how is free of both of these obstacles. This allows things can be built in a city. Houston is unique The author also pursued further the new channel to serve recreationally, and it amongst major American cities for not having conversations with Dr. Nikki Brand of TU Delft is already being used for rowing practices by ever passed a zoning ordinance (despite a to gain more information about the general a local school (Voskes, 2017). few attempts); however, aside from a land- process of Dutch development and planning. use map, Houston has its own form of the Also included in the greater implementation other aspects of the typical American zoning Case Study ‘Room for the River’ plan for the RFTR project in Nijmegen ordinance. The Room for the River Waal project had twin are various new developments and primary goals: reducing flood risk in Nijmegen redevelopments along the river. One such While it is true that Houston does not have a and the surrounding area, and improving the development, the first to be built, is the land-use map, the other aspects of a zoning urban spatial quality of the area. These goals Waalsprong (Figure 3). This is a development ordinance do exist. Builders must follow a arose because of the twin authority behind to be built on the northern shore of the complex set of regulations that amount to a the project itself: the national government Waal as part of the Vinex program for city code not telling where or what you can build, provided funding and oversight, while the expansion. After the completion of the but specifying in great detail how you must implementation of the project was left up Waalsprong, there is planned residential and build it. In Houston, rather than these rules to the municipality. This allowed the city mixed-use development for the new island being rolled into the zoning code, they exist of Nijmegen to incorporate its own goals created by the RFTR project (Lenis, 2017). in the general municipal code. For example, into the project vision, which smoothed the the city’s mandatory parking minimums 244 project’s local popular reception. (Chapter 26) and setback requirements 245 NIJMEGEN DISTRICT Ressen BOUNDARY Oosterhout Figure 3 (far right). Lent (Chapter 42), typically in a city’s zoning famous for its lack of zoning, does regulate Sources Nijmegen district ordinance, instead exist in Houston’s the form and nature of development in its Waal River boundary and areas municipal code. The code specifies different building code, it makes little to no attempt in Blackburn, Jim (2017). “HURRICANE/ currently being City Center rules for different uses, so although a regulating the location of said development. TROPICAL STORM HARVEY: POLICY developed (in color). developer can choose which use they would PERSPECTIVES”. Baker Institute for Public Oost like to construct, there are still regulations Houston’s lack of regulation on sprawl Policy. https://www.bakerinstitute.org/media/ Figure 4. governing each individual use case. This may has become the center of a lot of heated files/research_document/03d3e4fe/BI-pub- Map of urban De nieuweOld kaart City restrict the nature of what’s developed, but conversation after the devastating flooding Blackburn_Harvey-090617.pdf. development zoning van de Waalsprong critically contrasting with The Netherlands, caused by Hurricane Harvey. As Jim along Waal River there are little to no regulations on where a Blackburn states in his paper for the Baker Brand, Nikki (2017). Personal interview. June within the Nijmegen developer can build. Institute for Public Policy (2017): 12, 2017. municipality “Our pattern of development has been (Map courtesty of The Netherlands has strong anti-sprawl outward from the center of Houston and “The Delta Works”. Deltawerken. http://www. Gemeente Nijmegen - regulations, in that there are very restrictive up the watersheds of the various bayous deltawerken.com/Deltaworks/23.html Waalsprong Boek). rules on building outside of a city’s and creeks. As such, new development designated boundaries. Building a large-scale has dumped increased runoff onto older Gardner, Spencer (2017). “A History of Zoning development outside of a city’s designated downstream subdivisions and commercial in Three Acts — Part 1”. Strong Towns. June 44 | 45 nieuwe kaart boundaries is done primarily through one structures. Inadvertently, we have dumped 28, 2017. Web. https://www.strongtowns.org/ program: the Vinex program. Through runoff on older neighborhoods while journal/2017/6/28/a-history-of-zoning-in- cooperation with the national government, attempting to keep flood control costs three-acts-part-i the municipality is occasionally granted lower in new developments, effectively permission to purchase a parcel of land from subsidizing new development on the backs H+N+S Landscape Architecture. River its original owners. It then creates a general of the downstream residents” (Blackburn, Expansion + City Park. http://www.hnsland.nl/ plan for the use of this parcel, and auctions 2017). en/projects/room-river-nijmegen. it off to developers, whom are required to follow this use plan established by the Viewing the Dutch restrictions on urban “History of Nijmegen”. Radboud University. municipality. This allows the municipality to expansion from this perspective, it is http://www.ru.nl/english/@676086/history/ expand its borders, and also make money apparent that Houston’s policies should LEGEND (interview Brand, 2017). change in the interest of flood resilience. Kapur, Teddy. Land Use Regulation in Houston Contradicts the City’s Free Market water Currently very few Vinex developments are Reputation. January, 2004. Web. http:// being constructed, leading to more focus on www.pszjlaw.com/media/publication/427_ nature urban redevelopment. This is very different Kapur%20-%20ELR%20land%20use%20 from Houston and much of the United States, regulation.pdf woodland where there are few to no disincentives to building outside the city proper, leading to Lenis, Matthijs (2017). Personal interview. sports amenities sprawling metropolitan regions (interview June 12, 2017. Lenis, 2017). urban development Voskes, Andrea (2017). “Partnering the River: Conclusions Changing a Threat into a Chance”. Nijmegen, residential area Dutch authorities hold a tighter control over The Netherlands. June 6, 2017. Presentation to land-use planning, and critically, over city the NSF PIRE program participants. fringe development expansion. Through the Dutch Vinex program, the national government oversees the rate ‘green living’ of expansion of cities, and the government keeps this rate slow in order to incentivize ribbon development urban redevelopment and densification. This system is exemplified by the RFTR project diverse amenities in Nijmegen, which contains both a plan for city expansion on the north shore as well as existing businesses greater investment in the southern shore. This sharply contrasts with Houston, where new business area there are few incentives in favor of urban 246 redevelopment and infill. Houston, although 247 COLOPHON

NSF-PIRE COASTAL FLOOD RISK REDUCTION PROGRAM

AUTHENTIC LEARNING AND TRANSFORMATIVE EDUCATION: VOLUME I - 2015-2017

Editors Baukje Bee Kothuis Yoonjeong Lee Samuel Brody

Production Sherry Parker

Publication of this book has been funded by

National Science Foundation Center for Texas Beaches and Shores Partnerships for International (CTBS) at Texas A&M Galveston Research and Education (PIRE) (grant no. 1545837)

First edition, March 2018

Copyright © 2018 by the authors and editors, unless otherwise stated. All rights reserved. No part of this publication may be reproduced or stored by any electronic or mechanical means (including copying, photocopying, recording, data storage, and retrieval) or in any other form or language without the written permission of the editors or publisher.

The sources used preparing this book have been identified to the best of our ability and permission has been granted to use the materials. If a source has been incorrectly identified or appears without the 248 appropriate permission, please contact the publisher and/or editors.