DOCSLIB.ORG

A Case Study of the Holly Beach Breakwater System Andrew Keane Woodroof Louisiana State University and Agricultural and Mechanical College, [email protected]

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Case Study of the Holly Beach Breakwater System Andrew Keane Woodroof Louisiana State University and Agricultural and Mechanical College, Akwoodroof@Gmail.Com Louisiana State University LSU Digital Commons LSU Master's Theses Graduate School 2012 Determining the performance of breakwaters during high energy events: a case study of the Holly Beach breakwater system Andrew Keane Woodroof Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_theses Part of the Civil and Environmental Engineering Commons Recommended Citation Woodroof, Andrew Keane, "Determining the performance of breakwaters during high energy events: a case study of the Holly Beach breakwater system" (2012). LSU Master's Theses. 2184. https://digitalcommons.lsu.edu/gradschool_theses/2184 This Thesis is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Master's Theses by an authorized graduate school editor of LSU Digital Commons. For more information, please contact [email protected]. DETERMINING THE PERFORMANCE OF BREAKWATERS DURING HIGH ENERGY EVENTS: A CASE STUDY OF THE HOLLY BEACH BREAKWATER SYSTEM A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College In partial fulfillment of the Requirements for the degree of Master of Science in The Department of Civil and Environmental Engineering by Andrew K. Woodroof B.S., Louisiana State University, 2008 December 2012 ACKNOWLEDGEMENTS First and foremost, I would like to express my love and passion for the infinite beauty of south Louisiana. The vast expanse of wetlands, coastlines, and beaches in south Louisiana harbors people, industry, natural resources, recreation, and wildlife that is truly special. The intermingling of these components creates a multitude of unique cultures with such pride, passion, and zest for life that makes me thankful every day that I can enjoy the bounty of this region. The current need to restore and protect such vital and fragile resources is something very close to my heart and I am proud to devote my time, work, and hobbies towards that goal. I would also like to thank my graduate committee members. First, I would like to thank Dr. Kevin Xu for providing a fresh perspective on my work in coastal sciences and Dr. Heather Smith for her continued guidance and support. Dr. Clint Willson introduced me to the Coastal and Ecological Engineering program at LSU, and has been a mentor to me in both the academic and professional landscapes. Lastly, Dr. Jim Chen has been a tremendous mentor as I navigated the coastal engineering curriculum. I have gained a tremendous amount of technical knowledge while at LSU, but I believe that I have learned more about coastal engineering in my discussions with Dr. Chen than I have in any classroom. I would also like to acknowledge those entities which contributed to and encouraged the completion of my studies. The Louisiana Coastal Protection and Restoration Authority provided a wealth of information which made this project possible. I would also like to acknowledge my employer, Digital Engineering, for their support, understanding, and encouragement for completing my studies. Finally, I could not have realized my goals of completing this curriculum without the support of my friends and family, especially my parents, who have enabled and supported my every goal. I would not be where I am today without my wife, Mia, and her continuous support, motivation, patience and love, and for that I am thankful. ii TABLE OF CONTENTS ACKNOWLEDGEMENTS .................................................................................................................................................. ii LIST OF TABLES .............................................................................................................................................................. v LIST OF FIGURES ........................................................................................................................................................... vi ABSTRACT ................................................................................................................................................................... viii CHAPTER 1: INTRODUCTION .......................................................................................................................................... 1 1.1 Segmented Breakwaters .............................................................................................................................. 2 1.1.1 Emergent Breakwater Circulation Patterns ............................................................................................. 4 1.1.2 Overtopped Breakwater Circulation Patterns ......................................................................................... 5 1.1.3 Submerged Breakwater Circulation Patterns .......................................................................................... 7 CHAPTER 2: PURPOSE, HYPOTHESIS, AND STUDY OBJECTIVES ................................................................................... 11 2.1 Purpose ...................................................................................................................................................... 11 2.2 Hypothesis .................................................................................................................................................. 11 2.3 Study Objectives ......................................................................................................................................... 12 2.4 Tasks ........................................................................................................................................................... 13 CHAPTER 3: CASE STUDY: THE HOLLY BEACH BREAKWATER SYSTEM ......................................................................... 17 3.1 Introduction to the Holly Beach Breakwater System ................................................................................. 17 3.2 Holly Beach Breakwater System Project History and Design ..................................................................... 17 3.3 Previous Studies ......................................................................................................................................... 19 CHAPTER 4: METHODOLOGY ....................................................................................................................................... 22 4.1 Methods for Survey Data and Creation of 3-D Topographic Surfaces ....................................................... 22 4.1.1 Acquisition of Survey Data ..................................................................................................................... 22 4.1.2 Development of Survey Data Inventory ................................................................................................ 22 4.1.3 Modify Survey Data for Import into AutoCAD Civil 3D .......................................................................... 23 4.1.4 Generate Three-Dimensional Topographic Surfaces ............................................................................. 24 4.1.5 Generate Sediment Transport Volume Surfaces ................................................................................... 26 4.1.6 Calculate Volumes using Average-End-Area Method ............................................................................ 27 4.2 Methods for Acquisition, Import, Conversion, and Overlay for Aerial Photography ................................. 32 4.2.1 Acquisition and Characteristics of Aerial Photography ......................................................................... 32 4.2.2 Import of Aerial Photography into Civil 3D Model ................................................................................ 33 4.3 Interpolation of Survey Data ...................................................................................................................... 36 4.3.1 Purpose of Survey Data Interpolation ................................................................................................... 36 4.3.2 Identification of Survey Transects for Interpolation .............................................................................. 37 4.3.3 Processing of Survey Data for Creating New Transects ......................................................................... 38 4.3.4 Generation of Interpolated Surfaces ..................................................................................................... 40 4.4 Hydrodynamic Information ........................................................................................................................ 42 4.5 Selection of Data for Analysis..................................................................................................................... 42 CHAPTER 5: ANALYSIS OF VOLUMETRIC TRANSPORT SURFACES ................................................................................ 46 5.1 Validation of Non-Interpolated Volumetric Transport Surfaces ................................................................ 46 5.2 Sediment Transport Results for Surge Events ............................................................................................ 48 5.2.1 Impact of Hurricane Rita: Analysis of 2005 to 2006 .............................................................................. 50 5.2.2 Impact of Hurricane Ike: Analysis of 2006 to 2009 ...............................................................................
Load more

Recommended publications
  • GEOTEXTILE TUBE and GABION ARMOURED SEAWALL for COASTAL PROTECTION an ALTERNATIVE by S Sherlin Prem Nishold1, Ranganathan Sundaravadivelu 2*, Nilanjan Saha3
    PIANC-World Congress Panama City, Panama 2018 GEOTEXTILE TUBE AND GABION ARMOURED SEAWALL FOR COASTAL PROTECTION AN ALTERNATIVE by S Sherlin Prem Nishold1, Ranganathan Sundaravadivelu 2*, Nilanjan Saha3 ABSTRACT The present study deals with a site-specific innovative solution executed in the northeast coastline of Odisha in India. The retarded embankment which had been maintained yearly by traditional means of ‘bullah piling’ and sandbags, proved ineffective and got washed away for a stretch of 350 meters in 2011. About the site condition, it is required to design an efficient coastal protection system prevailing to a low soil bearing capacity and continuously exposed to tides and waves. The erosion of existing embankment at Pentha ( Odisha ) has necessitated the construction of a retarded embankment. Conventional hard engineered materials for coastal protection are more expensive since they are not readily available near to the site. Moreover, they have not been found suitable for prevailing in in-situ marine environment and soil condition. Geosynthetics are innovative solutions for coastal erosion and protection are cheap, quickly installable when compared to other materials and methods. Therefore, a geotextile tube seawall was designed and built for a length of 505 m as soft coastal protection structure. A scaled model (1:10) study of geotextile tube configurations with and without gabion box structure is examined for the better understanding of hydrodynamic characteristics for such configurations. The scaled model in the mentioned configuration was constructed using woven geotextile fabric as geo tubes. The gabion box was made up of eco-friendly polypropylene tar-coated rope and consists of small rubble stones which increase the porosity when compared to the conventional monolithic rubble mound.
    [Show full text]
  • Responses to Coastal Erosio in Alaska in a Changing Climate
    Responses to Coastal Erosio in Alaska in a Changing Climate A Guide for Coastal Residents, Business and Resource Managers, Engineers, and Builders Orson P. Smith Mikal K. Hendee Responses to Coastal Erosio in Alaska in a Changing Climate A Guide for Coastal Residents, Business and Resource Managers, Engineers, and Builders Orson P. Smith Mikal K. Hendee Alaska Sea Grant College Program University of Alaska Fairbanks SG-ED-75 Elmer E. Rasmuson Library Cataloging in Publication Data: Smith, Orson P. Responses to coastal erosion in Alaska in a changing climate : a guide for coastal residents, business and resource managers, engineers, and builders / Orson P. Smith ; Mikal K. Hendee. – Fairbanks, Alaska : Alaska Sea Grant College Program, University of Alaska Fairbanks, 2011. p.: ill., maps ; cm. - (Alaska Sea Grant College Program, University of Alaska Fairbanks ; SG-ED-75) Includes bibliographical references and index. 1. Coast changes—Alaska—Guidebooks. 2. Shore protection—Alaska—Guidebooks. 3. Beach erosion—Alaska—Guidebooks. 4. Coastal engineering—Alaska—Guidebooks. I. Title. II. Hendee, Mikal K. III. Series: Alaska Sea Grant College Program, University of Alaska Fairbanks; SG-ED-75. TC330.S65 2011 ISBN 978-1-56612-165-1 doi:10.4027/rceacc.2011 © Alaska Sea Grant College Program, University of Alaska Fairbanks. All rights reserved. Credits This book, SG-ED-75, is published by the Alaska Sea Grant College Program, supported by the U.S. Department of Commerce, NOAA National Sea Grant Office, grant NA10OAR4170097, projects A/75-02 and A/161-02; and by the University of Alaska Fairbanks with state funds. Sea Grant is a unique partnership with public and private sectors combining research, education, and technology transfer for the public.
    [Show full text]
  • Shore Protection by Offshore Breakwaters
    l§lHydraulics Research Wallingford SHORE PROTECTION BY OFFSHORE BREAKWATERS A H Brampton Ph .D J V Smallman Ph.D Report No SR 8 July 1985 Registered Office: Hydraulics Research Limited, Wallingford, Oxfordshire OX 10 8BA. Telephone: 0491 35381. Telex: 848552 Thi s report describes work carri ed out wi thin the research programme Commission B for the Ministry of Agriculture, Fisheri es and Food . The study was carri ed ou t in the Coas tal Processes Sect ion of the Mari time Engineering Department of Hydraulics Research . The departmental nominated officer is Mr A Alli son . The Company's nominated project officer is Dr S W Huntington. The report is publi s hed on behalf of MAFF but any op inions expressed are not necessarily those of the Ministry . C Crown copyri ght 19 85 ABSTRACT This report reviews the information available for the design and use of offshore breakwaters in shore protection. As an introduction to the subject the physical processes occurring in the lee of an offshore breakwater are described with reference to natural examples. This is followed by a survey of case histories, and mathematical and physical modelling techniques for offshore breakwaters. Some of the methods which are available for the design of a breakwater system are reviewed. Possible future developments in the design process are described, and the areas in which further research on the effects of offshore breakwaters is required are highlighted. CONTENTS Page EXECUTIVE SUMMARY 1 INTRODUCTION 1 2 OFFSHORE BREAKWATERS - THE PHYSICAL PROCESSES 2 2.1 Natural Examples 2 2.2 Physical processes 4 3 LITERATURE STUDY 6 3.1 Review of case histories 6 3.2 Physical model studies 10 3 .3 Ma thematical model studies 16 4 DESIGN METHODS FOR AN OFFSHORE BREAKWATER SYSTEM 19 4.1 Developing the initial design 19 4.2 Methods for improving the breakwa ter design 22 5 FUTURE DEVELOPMENT 26 6 CONCLUS IONS AND RECOMMENDATIONS 28 7 ACKNOWLEDGE MENTS 29 8 REFERENCES 30 FIGURES PLATES EXECUTIVE SUMMARY 1.
    [Show full text]
  • The Impact of Submerged Breakwaters on Sediment Distribution Along Marsh Boundaries
    water Article The Impact of Submerged Breakwaters on Sediment Distribution along Marsh Boundaries Iacopo Vona *, Matthew W. Gray and William Nardin Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USA; [email protected] (M.W.G.); [email protected] (W.N.) * Correspondence: [email protected] Received: 7 February 2020; Accepted: 31 March 2020; Published: 2 April 2020 Abstract: Human encroachment and development on coastlines have led to greater amounts of armoring of shorelines. Breakwaters are a common feature along coastlines, which are used to dampen wave energy and protect shorelines from flash floods or overwash events. Although common, their effects on sediment transport and marsh geomorphology are poorly understood. To address this gap, our study quantifies the effects of breakwaters on sediment transport and marsh evolution under different wave regimes using Delft3D-SWAN, a dynamic geomorphodynamic numerical model. Model configurations used the same numerical domain, but scenarios had different sediments, waves, tides, basin slopes and breakwater distances from the shoreline to explore how waves and tidal currents shape coastal margins. Model results suggested breakwaters were responsible for an average wave damping between 10–50%, proportional to the significant wave height across all modeled scenarios. Shear stress at the beginning of the marsh and the volume of sediment deposited at the end of the simulation (into the marsh behind the breakwater) increased on average between 20–40%, proportional to the slope and distance of the breakwater from the shoreline. Sediment trapping, defined as the ratio between the volume of sediment housed into the salt marsh behind and away from the breakwater, was found to be less than 1 from most model runs.
    [Show full text]
  • Harbor Protection Through Construction of Artificial Submerged Reefs
    Harbor Protection through Construction of Artificial Submerged Reefs Amarjit Singh, Vallam Sundar, Enrique Alvarez, Roberto Porro, Michael Foley (www.hawaii.gov) 2 Outline • Background of Artificial Reefs • Multi-Purpose Artificial Submerged Reefs (MPASRs) ▫ Coastline Protection ▫ Harbor Protection • MPASR Concept for Kahului Harbor, Maui ▫ Situation ▫ Proposed Solution • Summary 3 Background First documented First specifically Artificial reefs in First artificial reef Artificial reefs in artificial reefs in designed artificial Hawaii– concrete/tire in Hawaii Hawaii – concrete Z- U.S. reefs in U.S. modules modules 1830’s 1961 1970’s 1985-1991 1991- Present • Uses • Materials ▫ Create Marine Habitat ▫ Rocks; Shells ▫ Enhance Fishing ▫ Trees ▫ Recreational Diving Sites ▫ Concrete Debris ▫ Surfing Enhancement ▫ Ships; Car bodies ▫ Coastal Protection ▫ Designed concrete modules ▫ Geosynthetic Materials 4 Multi-Purpose Artificial Submerged Reefs (MPASRs) Specifically designed artificial reef which can provide: • Coastline Protection or Harbor Protection ▫ Can help restore natural beach dynamics by preventing erosion ▫ Can reduce wave energy transmitted to harbor entrances • Marine Habitat Enhancement ▫ Can provide environment for coral growth and habitat fish and other marine species. ▫ Coral can be transplanted to initiate/accelerate coral growth • Recreational Uses ▫ Surfing enhancement: can provide surfable breaking waves where none exist ▫ Diving/Snorkeling: can provide site for recreational diving and snorkeling 5 MPASRs as Coastal Protection Wave Transmission: MPASRs can reduce wave energy transmitted to shoreline. Kt = Ht/Hi K = H /H t t i Breakwater K = wave transmission t Seabed coefficient, (Pilarczyk 2003) Ht= transmitted wave height shoreward of structure Hi = incident wave height seaward of structure. 6 MPASRs as Coastal Protection • Wave Refraction: MPASR causes wave refraction around the reef, focusing wave energy in a different direction.
    [Show full text]
  • Coastal Erosion
    Guidance for Flood Risk Analysis and Mapping Coastal Erosion February 2018 Requirements for the Federal Emergency Management Agency (FEMA) Risk Mapping, Assessment, and Planning (Risk MAP) Program are specified separately by statute, regulation, or FEMA policy (primarily the Standards for Flood Risk Analysis and Mapping). This document provides guidance to support the requirements and recommends approaches for effective and efficient implementation. Alternate approaches that comply with all requirements are acceptable. For more information, please visit the FEMA Guidelines and Standards for Flood Risk Analysis and Mapping webpage (www.fema.gov/guidelines-and-standards-flood-risk-analysis-and- mapping). Copies of the Standards for Flood Risk Analysis and Mapping policy, related guidance, technical references, and other information about the guidelines and standards development process are all available here. You can also search directly by document title at www.fema.gov/library. Coastal Erosion February 2018 Guidance Document 40 Page i Document History Affected Section or Date Description Subsection Sections 2.1.1.1 and February Replaced Figures 2.1.1-1, 2.1.1-2, and 2.1.1-3 to contain 2.1.1.2 2018 correct reference to water level above which Primary Frontal Dune reservoir volume is determined. Coastal Erosion February 2018 Guidance Document 40 Page ii Table of Contents 1.0 Overview ............................................................................................................................ 1 1.1 Beach and Shoreline Settings ........................................................................................ 2 1.1.1 Sandy Beach Backed by High Sand Dune: ............................................................. 3 1.1.2 Sandy Beach Backed by Low Sand Dune Berm: .................................................... 4 1.1.3 Sandy Beach Backed by Shore Protection Structure: ............................................. 4 1.1.4 Mixed Grain Size Beach .........................................................................................
    [Show full text]
  • Shoreline Stabilisation
    Section 5 SHORELINE STABILISATION 5.1 Overview of Options Options for handling beach erosion along the western segment of Shelley Beach include: • Do Nothing – which implies letting nature take its course; • Beach Nourishment – place or pump sand on the beach to restore a beach; • Wave Dissipating Seawall – construct a wave dissipating seawall in front of or in lieu of the vertical wall so that wave energy is absorbed and complete protection is provided to the boatsheds and bathing boxes behind the wall for a 50 year planning period; • Groyne – construct a groyne, somewhere to the east of Campbells Road to prevent sand from the western part of Shelley Beach being lost to the eastern part of Shelley Beach; • Offshore Breakwater – construct a breakwater parallel to the shoreline and seaward of the existing jetties to dissipate wave energy before it reaches the beach; and • Combinations of the above. 5.2 Do Nothing There is no reason to believe that the erosion process that has occurred over at least the last 50 years, at the western end of Shelley Beach, will diminish. If the water depth over the nearshore bank has deepened, as it appears visually from aerial photographs, the wave heights and erosive forces may in fact increase. Therefore “Do Nothing” implies that erosion will continue, more structures will be threatened and ultimately damaged, and the timber vertical wall become undermined and fail, exposing the structures behind the wall to wave forces. The cliffs behind the wall will be subjected to wave forces and will be undermined if they are not founded on solid rock.
    [Show full text]
  • Functional Design of Coastal Structures
    FUNCTIONALFUNCTIONAL DESIGNDESIGN OFOF David R. Basco, Ph.D, P.E. Director, The Coastal Engineering Center Old Dominion University,Norfolk, Virginia USA 23529 [email protected] DESIGNDESIGN OFOF COASTALCOASTAL STRUCTURESSTRUCTURES •• FunctionFunction ofof structurestructure •• StructuralStructural integrityintegrity •• PhysicalPhysical environmentenvironment •• ConstructionConstruction methodsmethods •• OperationOperation andand maintenancemaintenance OUTLINEOUTLINE •• PlanPlan formform layoutlayout - headland breakwaters - nearshore breakwaters - groin fields • WaveWave runuprunup andand overtopping*overtopping* - breakwaters and revetments (seawalls, beaches not covered here) •• WaveWave reflectionsreflections (materials(materials includedincluded inin notes)notes) * materials from ASCE, Coastal Engineering Short Course, CEM Preview, April 2001 SHORESHORE PARALLELPARALLEL BREAKWATERS:BREAKWATERS: HEADLANDHEADLAND TYPETYPE Design Rules, Hardaway et al. 1991 • Use sand fill to create tombolo for constriction from land • Set berm elevation so tombolo always present at high tide • Set Yg/Lg =• 1.65 for stable shaped beach • Set Ls/Lg = 1 • Always combine with new beach fill • See CEM 2001 V-3 for details KEYKEY VARIABLESVARIABLES FORFOR NEARSHORENEARSHORE BREAKWATERBREAKWATER DESIGNDESIGN Dally and Pope, 1986 Definitions: Y = breakwater distance from nourished shoreline Ls = length of breakwater Lg = gap distance d = water depth at breakwater (MWL) ds = water depth• at breakwater (MWL) •Tombolo formation: Ls/Y = 1.5 to 2 single = 1.5 system •Salient formation: Ls/ = 0.5 to 0.67 = 0.125 long systems (a) (b) Process Parameter Description 1. Bypassing Dg/Hb Depth at groin tip/breaking wave height 2. Permeability • Over-passing Zg (y) Groin elevation across profile, tidal range • Through-passing P(y) Grain permeability across shore • Shore-passing Zb/R Berm elevation/runup elevation 3. Longshore transport Qn/Qg Net rate/gross rate Property Comment 1. Wave angle and wave height Accepted.
    [Show full text]
  • The Study of the Coastal Management Criteria Based on Risk Assessmeant: a Case Study on Yunlin Coast, Taiwan
    water Article The Study of the Coastal Management Criteria Based on Risk Assessmeant: A Case Study on Yunlin Coast, Taiwan Wei-Po Huang 1,2,* ID , Jui-Chan Hsu 1, Chun-Shen Chen 3 and Chun-Jhen Ye 1 1 Department of Harbor and River Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan; [email protected] (J.-C.H.); [email protected] (C.-J.Y.) 2 Center of Excellence for Ocean Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan 3 Water Resources Planning Institute, Water Resources Agency, Ministry of Economic Affairs, Taichung 41350, Taiwan; [email protected] * Correspondence: [email protected]; Tel.: +886-2-2462-2192 (ext. 6154) Received: 18 June 2018; Accepted: 25 July 2018; Published: 26 July 2018 Abstract: In this study, we used the natural and anthropogenic characteristics of a coastal region to generate risk maps showing vulnerability and potential hazards, and proposed design criteria for coastal defense and land use for the various kinds of risks faced. The Yunlin coast, a first-level protection area in mid-west Taiwan, was then used as an example to illustrate the proposed design criteria. The safety of the present coastal defenses and land use of the Yunlin coastal area was assessed, and coastal protection measures for hazard prevention were proposed based on the generated risk map. The results can be informative for future coastal management and the promotion of sustainable development of coastal zones. Keywords: coastal defense; risk maps; non-engineering measure; coastal vulnerability 1. Introduction Like most developing countries, Taiwan’s coast has been alternatively used for settlement, agriculture, trade, industry, and recreation without careful and thorough planning in the development stage since 70s.
    [Show full text]
  • San Andrés, Old Providence and Santa Catalina (Caribbean Sea, Colombia)
    REEF ENVIRONMENTS AND GEOLOGY OF AN OCEANIC ARCHIPELAGO: SAN ANDRÉS, OLD PROVIDENCE AND SANTA CATALINA (CARIBBEAN SEA, COLOMBIA) with Field Guide JÓRN GEISTER Y JUAN MANUEL DÍAZ República de Colombia MINISTERIO DE MINAS Y ENERGÍA INSTITUTO COLOMBIANO DE GEOLOGÍA Y MINERÍA INGEOMINAS REEF ENVIRONMENTS AND GEOLOGY OF AN OCEANIC ARCHIPELAGO: SAN ANDRÉS, OLD PROVIDENCE AND SANTA. CATALINA (CARIBBEAN SEA, COLOMBIA with FIELD GUIDE) INGEOMINAS 2007 DIAGONAL 53 N°34-53 www.ingeominas.gov.co DIRECTOR GENERAL MARIO BALLESTEROS MEJÍA SECRETARIO GENERAL EDWIN GONZÁLEZ MORENO DIRECTOR SERVICIO GEOLÓGICO CÉSAR DAVID LÓPEZ ARENAS DIRECTOR SERVICIO MINERO (e) EDWARD ADAN FRANCO GAMBOA SUBDIRECTOR DE GEOLOGÍA BÁSICA ORLANDO NAVAS CAMACHO COORDINADORA GRUPO PARTICIPACIÓN CIUDADANA, ATENCIÓN AL CLIENTE Y COMUNICACIONES SANDRA ORTIZ ÁNGEL AUTORES: 315RN GEISTER Y JUAN MANUEL DÍAZ REVISIÓN EDITORIAL HUMBERTO GONZÁLEZ CARMEN ROSA CASTIBLANCO DISEÑO Y DIAGRAMACIÓN GUSTAVO VEJARANO MATIZ J SILVIA GUTIÉRREZ PORTADA: Foto: Estación en el mar Cl. San Andrés: Pared vertical de Bocatora Hole a -30 m. El coral Montastraea sp. adoptó una forma plana. Agosto de 1998. IMPRESIÓN IMPRENTA NACIONAL DE COLOMBIA CONTENT PREFACE 7 1. GENERAL BACKGROUND 8 2. STRUCTURAL SETTING AND REGIONAL GEOLOGY OF THE ARCHIPÉLAGO 9 2.1 Caribbean Piafe 9 2.2 Upper and Lower Nicaraguan Rises 9 2.3 Hess Escarpment and Colombia Basin 11 2.4 Islands and atolls of the Archipelago 12 3. CLIMATE AND OCEANOGRAPHY 14 4. GENERAL CHARACTERS OF WESTERN CARIBBEAN OCEANIC REEF COMPLEXE (fig. 7)
    [Show full text]
  • NH Volunteer Beach Profiling Report 2020 North Hampton State Beach, NH
    NH Volunteer Beach Profiling Report 2020 North Hampton State Beach, NH North Hampton State Beach is strongly affected by two NHB01 landmasses, Little Boar’s Head to the north and Godfreys Ledge to the south (see map). Overall, the beach at profiling station NHB01 is narrow, steep, and can change very quickly. The beach is often covered with a thin layer of sand during accretional conditions, but during erosional periods the sand veneer is easily eroded, revealing cobbles and boulders. During major storms, these cobbles and boulders are pushed up forming a ramp against the concrete seawall. Max and min average elevation The figure above shows beach elevation profiles that extend from the seawall to the low tide line at profiling station NHB01. The February 2018 (red) profile depicts pre-storm beach conditions. The March 2018 profiles (black and blue) show the impact of the 2018 nor’easters. Note the erosion of the lower beach contrasted by the increase in elevation at the seawall in the post-storm profiles. This increase in elevation at the seawall in March is due to the formation of the gravel ramp mentioned above from sediment being pushed landward by the waves. Once formed, the ramp allows pebbles and cobbles to overtop the seawall causing additional damage to the infrastructure. Changes in sand A B C volume at NB01 Each blue line represents the estimated volume of sediment measured along a 1-meter- wide swath of the beach for each given date at NHB01. A series NHB01 Storm effects and recovery of storms in Mar 2018 caused major erosion.
    [Show full text]
  • Machair3.Pdf
    • • a a • • • • tr77- (2.12-2,) ' qAPt 511-h (2-5-2.). Frontispiece Photo. Machair Group Meeting, Outer Hebrides, July 1978(Photo: D.S. Ranwell). á Natural Environment Research Council Institute of Terrestrial Ecology Sand Dune Machair 3 Report on meeting in the Outer Hebrides 14-16th July 1978 Edited by D.S. Ranwell (1980) Institute of Terrestrial Ecology, University of East Anglia, Norwich Printed ir England by NERC Reprogriphic Section Swindon © 1981 Published in 1981 by Institute of Terrestrial Ecology 68 Hills Road Cambridge CB2 ILA Dr. D S Ranwell, School of Biological Scien6es, University of East Anglia, Norwich, NR4 7TJ 0603 (Norwich) 56161 Cover Drawing by Sid Lewis ,The Institute of Terrestrial Ecology (ITE) was established in 1973, from the former Nature Conservancy's research stations and staff, joined later by the Institute of Tree Biology and the Culture Centre of Algae and Protozoa. ITE contributes to and draws upon the collective knowledge of the fourteen sister institutes which Make up the Natural Environment Research Council, spanning all the environmental sciences. The Institute studies the factors determining the structure, composition and processes of land and fresh- water systems, and of individual plant and animal species. It is developing a sounder scientific basis for predicting and modelling environmental trends arising from natUral or man-made change. The results of this research are available to those responsible for the protection, management and wise use of our natural resources. Nearly half of ITE's work is research commissioned by customers, such as the Nature Conservancy Council who require information for wildlife conservation, the Department of Energy, the Department of the EnvironMent and the EEC.
    [Show full text]