Chapter 5.1 Coastal Hazards
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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. -
Coastal Hazards Primers
Coastal Hazards Primers Table of Contents Introduction ............................................................................................................................................................................. 2 Flooding .................................................................................................................................................................................... 2 Background ......................................................................................................................................................................... 2 Flood Mapping .................................................................................................................................................................... 2 Flood Management ........................................................................................................................................................... 2 Flood Mitigation .................................................................................................................................................................. 2 Flood Response and Recovery ............................................................................................................................................ 3 Wind ........................................................................................................................................................................................... 3 Background ........................................................................................................................................................................ -
Linktm Gabions and Mattresses Design Booklet
LinkTM Gabions and Mattresses Design Booklet www.globalsynthetics.com.au Australian Company - Global Expertise Contents 1. Introduction to Link Gabions and Mattresses ................................................... 1 1.1 Brief history ...............................................................................................................................1 1.2 Applications ..............................................................................................................................1 1.3 Features of woven mesh Link Gabion and Mattress structures ...............................................2 1.4 Product characteristics of Link Gabions and Mattresses .........................................................2 2. Link Gabions and Mattresses .............................................................................. 4 2.1 Types of Link Gabions and Mattresses .....................................................................................4 2.2 General specification for Link Gabions, Link Mattresses and Link netting...............................4 2.3 Standard sizes of Link Gabions, Mattresses and Netting ........................................................6 2.4 Durability of Link Gabions, Link Mattresses and Link Netting ..................................................7 2.5 Geotextile filter specification ....................................................................................................7 2.6 Rock infill specification .............................................................................................................8 -
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. -
Chapter 213 the Impacts of Shoreline Protection
CHAPTER 213 THE IMPACTS OF SHORELINE PROTECTION STRUCTURES ON BEACHES ALONG MONTEREY BAY, CALB^ORNIA GaryB. Griggs* James F. Tait* Katherine Scott* Abstract As a result of severe coastal storm damage in recent years along the California coast and the continuation of development and redevelopment in hazard prone oceanfront areas, large numbers of coastal protection structures have been built. This same trend has been observed on the Atlantic and Gulf coasts as well. At present, fully 12%, or 130 miles of California's 1100 miles of shoreline have been armored. As the number of structures and their coastal frontage has increased, concern along the California coast and elsewhere has arisen in regard to the impacts of these protective structures on the adjacent beaches. Three Atlantic coast states (Maine, New Jersey, and North Carolina) have responded to this concern by establishing state-level policy which prohibits construction of any new "hard" protective structures. Although considerable laboratory scale research has been carried out on this problem, field work has been extremely limited. A study along the central California coast was initiated in order to resolve some of the most critical questions regarding the impacts of protection structures on beaches. Based on 4 years of precise, biweekly, shore- based surveys in the vicinity of different types of seawalls along the shoreline of northern Monterey Bay along the central California coast, some consistent beach changes have been documented. All of the changes observed to date have been seasonal and are best developed in the fall and winter months during the transition from summer swell to winter storm conditions. -
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. -
Chapter 18, Lesson 3 World War One Trench Warfare
Name:______________________________________ Chapter 18, Lesson 3 World War One Trench Warfare Below are illustrations of a typical World War One trench system. Use the proceeding illustrations to answer the questions. Key 1. Were the artillery batteries (cannons, mortars, and large guns) located in front or behind the infantry soldiers in the trenches? Why might it be set up this way? _____________________________________________________________________________ _____________________________________________________________________________ 2. Based on the location of the listening posts, what was their purpose? _____________________________________________________________________________ ______________________________________________________________________________ 3. The communication trenches connected the first support line trench to what three areas? _____________________________________________________________________________ _____________________________________________________________________________ 4. What would be the reason for having wire breaks in the barbed wire entanglements? _____________________________________________________________________________ ______________________________________________________________________________ 5. After answering questions 14 and 15, tell what two parts of the trench were used to minimize the devastation from explosions. ______________________________________________________________________________ 6. This allowed soldiers to see over the trench when shooting the enemy. ________________ -
Example Language for Identifying Sea Level Rise and Coastal Hazards Information Necessary for a Complete CDP Application
STATE OF CALIFORNIA—NATURAL RESOURCES AGENCY EDMUND G. BROWN, JR., GOVERNOR CALIFORNIA COASTAL COMMISSION 45 FREMONT STREET, SUITE 2000 SAN FRANCISCO, CA 94105- 2219 VOICE (415) 904- 5200 FAX ( 415) 904- 5400 TDD (415) 597-5885 To: Coastal Commission District Staff, Coastal Planning Departments From: Kelsey Ducklow, Coastal Commission, Statewide Planning Unit Date: January 3, 2019 Re: Example language for identifying sea level rise and coastal hazards information necessary for a complete CDP application Purpose This memo is intended to provide coastal analysts with information and example language that can be used in a non-filing/incomplete letter (or to gather information prior to submittal of a CDP application) when asking for an analysis of coastal hazards and sea level rise from an applicant. This language is generally similar to the information coastal analysts have requested in the past to be included in technical studies that analyze potential impacts from coastal hazards, but includes additional detail on how to incorporate sea level rise into those analyses. Please note that the information and example language below pertains only to the coastal hazards-related portion of a CDP application. It is not meant to address other common issues such as the need for a more detailed project description or project plans, or additional information on impacts to public access and recreation, ESHA, visual resources, and so on, except insomuch as there is overlap with those issues and coastal hazards. Additionally, note that in most cases, the example language below will need to be modified, expanded, or deleted to address site or project-specific concerns. -
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. -
Geotechnical Aspects of Seawall Stability with Climate Change
GEOTECHNICAL ASPECTS OF SEAWALL STABILITY WITH CLIMATE CHANGE Lex Nielsen WorleyParsons [email protected] Agustria Salim Pells Sullivan Meynink Doug Lord Coastal Environment Geoff Withycombe Sydney Coastal Councils Group Ian Armstrong Sydney Coastal Councils Group Introduction Existing seawalls and protection structures exist at many locations around the Australian coast where construction details are unknown and the capacity of the structures to withstand storms has not been verified. Seawall asset owners and managers (usually Local Councils) are faced with determining development applications in areas protected by such structures. Often, the responsibility, ownership and liability arising from these structures are not clear, with many structures constructed entirely or in part on Public Land. Frequently, there is conflict between the coastal managers and the community who have varying impressions of their effectiveness in providing protection and their impact on the public beach. This project has developed methods whereby the efficacy of existing seawalls may be determined. The project was undertaken by the Sydney Coastal Councils Group (SCCG) with funding provided by the Commonwealth Department of Climate Change and Energy Efficiency (DCCEE) through a Climate Adaptation Pathways (CAP) grant. The project was overseen by a National Reference Group comprising expertise from local government, state government, universities with coastal management expertise and industry specialists. Key elements of the project were as follows: Literature review of existing seawall types, remote sensing techniques, options for upgrading, certification requirements - Water Research Laboratory (WRL), University of NSW (UNSW). Geotechnical assessment of structure types and common failure modes - WorleyParsons. Economic aspects of the decision making process - Bond University under the direction of the Centre for Coastal Management (CCM) at Griffith University (GU). -
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. -
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 .........................................................................................