Shoreline Protection Research Articles

The relationship of spatial–temporal changes in fringe mangrove extent and adjacent land-use: Case study of Kien Giang coast, Vietnam

Fringe mangroves are recognised as a highly valuable resource due to their provision of multiple ecosystem services. However, accelerating human-pressures on mangrove forests are resulting in the loss of key mangrove ecosystem services. In this paper, we assessed spatial–temporal changes in the extent and width of fringe mangroves, and changes in adjacent land use. The study focused on the Kien Giang Province, Vietnam, for the period 1989–2009. The total mangrove extent was estimated at seven points in time using four Landsat TM images (1989, 1992, 2003, and 2006) and three SPOT images (1995, 2003 and 2009). Supervised classification was conducted for image classification and mapping changes using a Maximum Livelihood Classifier approach. Changes in mangrove width were calculated for 2003 and 2009 using the Digital Shoreline Analysis Application.An assessment of the four Landsat TM images showed a significant decrease in mangrove extent for the periods 1989–1992 (−2.7% yr−1) and 2003–2006 (−2.1% yr−1), while a significant increase in mangrove extent was observed during 1992–2003 (0.7% yr−1). SPOT images were used to classify shoreline land cover into four types, namely mangroves; shrimp farms; built-up areas; and bare and wet ground areas. The total loss of fringe mangrove extent was significantly correlated with the increase in extent of other land covers, especially shrimp farms and bare and wet ground, during the period of 2003–2009.The overall accuracy assessment of the classification using 2003 and 2009 SPOT 5 images was 90.1% and 90.5% respectively. The overall accuracy assessment of the 2003 Landsat image was 92.1%. This accuracy in classification of mangroves and non-mangroves showed that use of Landsat images was adequate for assessing spatial–temporal mangrove dynamics when higher spatial resolution satellite images were limited. The results highlight the dynamic nature of fringe mangrove communities in the region, and provide data useful for informing shoreline mangrove rehabilitation, conservation efforts, and national monitoring programs for estimating mangrove values of carbon sequestration and shoreline protection functions in Vietnam.

Predicting the Effects of Proposed Mississippi River Diversions on Oyster Habitat Quality; Application of an Oyster Habitat Suitability Index Model

ABSTRACT In an attempt to decelerate the rate of coastal erosion and wetland loss, and protect human communities, the state of Louisiana developed its Comprehensive Master Plan for a Sustainable Coast. The master plan proposes a combination of restoration efforts including shoreline protection, marsh creation, sediment diversions, and ridge, barrier island, and hydrological restoration. Coastal restoration projects, particularly the large-scale diversions of fresh water from the Mississippi River, needed to supply sediment to an eroding coast potentially impact oyster populations and oyster habitat. An oyster habitat suitability index model is presented that evaluates the effects of a proposed sediment and freshwater diversion into Lower Breton Sound. Voluminous freshwater, needed to suspend and broadly distribute river sediment, will push optimal salinities for oysters seaward and beyond many of the existing reefs. Implementation and operation of the Lower Breton Sound diversion structure as proposed wou...

The importance of structural complexity in coral reef ecosystems

The importance of structural complexity in coral reefs has come to the fore with the global degradation of reef condition; however, the limited scale and replication of many studies have restricted our understanding of the role of complexity in the ecosystem. We qualitatively and quantitatively (where sufficient standardised data were available) assess the literature regarding the role of structural complexity in coral reef ecosystems. A rapidly increasing number of publications have studied the role of complexity in reef ecosystems over the past four decades, with a concomitant increase in the diversity of methods used to quantify structure. Quantitative analyses of existing data indicate a strong negative relationship between structural complexity and algal cover, which may reflect the important role complexity plays in enhancing herbivory by reef fishes. The cover of total live coral and branching coral was positively correlated with structural complexity. These habitat attributes may be creating much of the structure, resulting in a collinear relationship; however, there is also evidence of enhanced coral recovery from disturbances where structural complexity is high. Urchin densities were negatively correlated with structural complexity; a relationship that may be driven by urchins eroding reef structure or by their gregarious behaviour when in open space. There was a strong positive relationship between structural complexity and fish density and biomass, likely mediated through density-dependent competition and refuge from predation. More variable responses were found when assessing individual fish families, with all families examined displaying a positive relationship to structural complexity, but only half of these relationships were significant. Although only corroborated with qualitative data, structural complexity also seems to have a positive effect on two ecosystem services: tourism and shoreline protection. Clearly, structural complexity is an integral component of coral reef ecosystems, and it should be incorporated into monitoring programs and management objectives.

Degradation and resilience in Louisiana salt marshes after the BP–Deepwater Horizonoil spill

More than 2 y have passed since the BP-Deepwater Horizon oil spill in the Gulf of Mexico, yet we still have little understanding of its ecological impacts. Examining effects of this oil spill will generate much-needed insight into how shoreline habitats and the valuable ecological services they provide (e.g., shoreline protection) are affected by and recover from large-scale disturbance. Here we report on not only rapid salt-marsh recovery (high resilience) but also permanent marsh area loss after the BP-Deepwater Horizon oil spill. Field observations, experimental manipulations, and wave-propagation modeling reveal that (i) oil coverage was primarily concentrated on the seaward edge of marshes; (ii) there were thresholds of oil coverage that were associated with severity of salt-marsh damage, with heavy oiling leading to plant mortality; (iii) oil-driven plant death on the edges of these marshes more than doubled rates of shoreline erosion, further driving marsh platform loss that is likely to be permanent; and (iv) after 18 mo, marsh grasses have largely recovered into previously oiled, noneroded areas, and the elevated shoreline retreat rates observed at oiled sites have decreased to levels at reference marsh sites. This paper highlights that heavy oil coverage on the shorelines of Louisiana marshes, already experiencing elevated retreat because of intense human activities, induced a geomorphic feedback that amplified this erosion and thereby set limits to the recovery of otherwise resilient vegetation. It thus warns of the enhanced vulnerability of already degraded marshes to heavy oil coverage and provides a clear example of how multiple human-induced stressors can interact to hasten ecosystem decline.

Economic value of mangrove ecosystems in the Panama village, Ampara district:a case study

Sri Lanka encompasses a high diversity of coastal vegetation, specifically mangroves and these ecosystems have provided a wide array of goods and services, ranging from fishery, forest products and tourism to shoreline protection. The need to assess the economic value of mangroves became more eminent to assist policy-makers and funding agencies in integrating mangrove restoration activities in environmental conservation programs. The study was initiated to estimate the direct and indirect values of mangrove ecosystems and the protection role played at extreme disastrous events such as Tsunami to the coastal communities in Ampara District of Sri Lanka. Information on eco-physical and socioeconomic including various damage costs and dependency on mangrove ecosystems was collected using purposive sampling from 109 households from Panama village which was characterized with well managed and functioning coastal ecosystems where mangroves were relatively intact. The shoreline protection value was assessed by comparing the Panama village with 100 coastal households from villages in Potuvil town where mangrove ecosystem was comparatively degraded due to tsunami. The results revealed a higher mangrove dependence of the Panama villagers with a value of Rs.119, 438/household/year (US$1,171). It was also revealed that estimated incidence of damage costs in areas with degraded mangrove vegetation was significantly greater during the tsunami. The costs of damages to livelihood and property in Potuvil (US$ 13,509) were approximately twenty times the costs of damages in Panama (US$ 623). Field observation also revealed massive destruction to the coastal ecosystem (property and vegetation damages and sea erosion) in Potuvil compared to Panama. Results clearly indicated that areas with intact mangrove ecosystem generate greater economic benefits. The findings also indicate the economic rationale of including mangrove restoration efforts in the environmental conservation programs.

Mangrove Eco-system and their Multifunctionalities: An Analysis of the Provision of Economic and Environmental Livelihoods to the Fishermen Communities in the South-East Coast of India

A study was conducted to analyze the direct and indirect benefits of Pitchavaram Mangrove Forests (PMF)in the south east coast region of Tamil Nadu, India, where the concentration of mangrove biosphere is substantial. For the study,30 numbers each of i. Fishermen and ii. Tourists were personally contacted. About 75% of the respondents depended mangrove area for fishing while coastal area was the source of fish catch for only 25% of sample respondents. Among the tourists respondents, only 3.3% were foreigners, 10% were from other states and the rest were domestic visitors. Most of tourists were young and middle aged and about 43% had a monthly income of Rs.15001 to 30000. It is understood that high income and educated people showed more interest in visiting places of natural origin. People who travelled by own vehicles had higher visitation rate of 50% than those travelling by hired vehicles owing to the high cost of hired vehicles. The principal products collected by local stakeholders were firewood, fodder and timber. The Individual Travel Cost Method (ITCM) was used to estimate the recreational value and the determinants of visitation rate. The marital status had a negative influence on visitation rate. It was found out that bachelors had made more frequent trips to PMF than the families. The monthly income was also significant and had the expected relationship. Travel cost had a significant influence on frequency of visits. The price elasticity of demand for recreational visit was estimated to be -0.1566. It indicated that the visitation rate was inelastic with respect to the travel cost i.e. one per cent increase in travel cost would result in only 0.1566% reduction in visitation rate. The option value of conserving the PMF was estimated using contingent valuation method using the bidding game technique. The fishermen were willingness to pay an amount of Rs.1763 towards internalizing externalities. The catchment area, monthly income and duration of fishing were positively related to Willingness To Pay (WTP) and were significant. It is implicit from the analysis that duration of fishing and fishing area (near mangrove) influenced the WTP significantly. Household expenditure of a fisherman had been positively related to the duration of fishing. The major findings of the regression results regarding the overall impact of PMF was that the people who entered into fishing and other mangrove dependent occupations had extensively improved their standard of living. The additional money generated from tourism by tourist dependents encouraged the households to incur more on luxurious goods. Positive externalities like shoreline protection, increased fish catch and enhanced income, utilization of non â-“timber forest products, control of soil erosion, water retention and purification of water by mangrove forests were the other environmental benefits. The study came out with the policy that the optimal exploitation of mangrove biosphere by the end users should be ensured by the enforcement authorities. Both the state and central institutions should protect the mangrove ecology and sea-shore through stringent adoption of regulatory mechanisms. The local institutions should also be empowered adequately to deal with the free-riders; so that the mangroves will be promoted on large scale since off-shore fishing has been the lifeline of the poor and marginalized fisher folk in coastal regions.

Economic Analysis of Impacts of Sea Level Rise and Adaptation Strategies in Transportation

Although the causes of the sea level rise (SLR) are hotly debated, almost no disagreement exists that sea levels will continue to rise. The SLR is likely to have significant impacts on coastal transportation infrastructure. Adaptations in response to the SLR are in urgent need. Facing various adaptation strategies, decision makers need information on the impacts of different SLR scenarios as well as the economic trade-offs of various adaptation strategies. This research attempts to quantify the economic impacts of the SLR as well as the costs and benefits of adaptation strategies by using cost–benefit analysis at the local level. Hillsborough County, Florida, is used as a case study, and two projected scenarios for the SLR are applied to it. Light detection and ranging data, parcel land use data, and transportation network data for the county are employed to estimate the impacts of the two scenarios. Three adaptation strategies are suggested to the proposed SLR scenarios. Then cost–benefit analysis is conducted for each strategy under the two scenarios that consider the impacts of both direct inundation costs and indirect travel time costs. On the basis of the present values of the net benefits in the proposed strategies, managed retreat with critical infrastructure protection is the best adaptation strategy for the SLR in the long run and the length of shoreline protection is the most sensitive to the net benefits.

Monte Carlo simulation model for economic evaluation of rubble mound breakwater protection in Harbors

The US Army Corps of Engineers has a mission to conduct a wide array of programs in the arenas of water resources, including coastal protection. Coastal projects must be evaluated according to sound economic principles, and considerations of risk assessment and sea level change must be included in the analysis. Breakwaters are typically nearshore structures designed to reduce wave action in the lee of the structure, resulting in calmer waters within the protected area, with attendant benefits in terms of usability by navigation interests, shoreline protection, reduction of wave runup and onshore flooding, and protection of navigation channels from sedimentation and wave action. A common method of breakwater construction is the rubble mound breakwater, constructed in a trapezoidal cross section with gradually increasing stone sizes from the core out. Rubble mound breakwaters are subject to degradation from storms, particularly for antiquated designs with under-sized stones insufficient to protect against intense wave energy. Storm waves dislodge the stones, resulting in lowering of crest height and associated protective capability for wave reduction. This behavior happens over a long period of time, so a lifecycle model (that can analyze the damage progression over a period of years) is appropriate. Because storms are highly variable, a model that can support risk analysis is also needed. Economic impacts are determined by the nature of the wave climate in the protected area, and by the nature of the protected assets. Monte Carlo simulation (MCS) modeling that incorporates engineering and economic impacts is a worthwhile method for handling the many complexities involved in real world problems. The Corps has developed and utilized a number of MCS models to compare project alternatives in terms of their costs and benefits. This paper describes one such model, Coastal Structure simulation (CSsim) that has been developed specifically for planning level analysis of breakwaters.

Impacts of Riprap on Wetland Shorelines, Upper Winnebago Pool Lakes, Wisconsin

Isolation of causative factors has proved challenging in characterizing the physical, chemical, and biological effects of shoreline hardening on the nearshore environment because of logistical challenges in identifying comparable sites. Extensive shoreline hardening and interspersion with unaltered shores in the large, shallow lakes in central Wisconsin provide an opportunity to surmount this. We compared the effects of shoreline protection on wave climate, bottom topography and substrate, water quality, and plant and animal assemblages at five adjacent pairs of natural and armored (riprapped) shorelines. Armored shorelines were characterized by coarser, more compacted substrates with lower organic content; cooler temperatures with higher dissolved oxygen; and greater water clarity. Differences in physical and chemical properties likely influenced plant growth forms and fish feeding guild differences between riprapped and natural sites. For example, floating-leaved plants were more abundant and fish were nearly twice as abundant and were represented by larger individuals at natural versus armored shorelines. Substrate characteristics may account for the differences in water quality and plant and animal associations observed in this study. As shoreline property owners continue to install riprap as protection against erosion, we expect the nearshore environment and associated biological communities to increasingly reflect this practice.

Shoreline retreat and sediment release in response to accelerating sea level rise: Measuring and modelling cliffline dynamics on the Suffolk Coast, UK

Contemporary and historic data for shoreline retreat are used to evaluate and test a range of models that predict shoreline response to accelerating sea level rise. Models are tested against the known record of sea level rise acceleration over the twentieth century on the cliffline position of a series of soft rock cliffs located along the Suffolk Coast, UK. These cliffs have experienced high retreat rates throughout the twentieth century (between 2 and 4.5 m a − 1 ). The shoreline response model most suited to such an assessment is the SCAPE model, with a close fit between actual and modelled shoreline positions. Retreating shorelines also have associated changes in alongshore elevation, an aspect of shoreline retreat that has attracted little attention. Recently acquired IfSar data now permit detailed and accurate assessment of ground elevation from which the elevation of future clifflines can be derived. Combining elevation data with future shoreline retreat, also predicted using the SCAPE model, enables future sediment release from the cliffs to be evaluated. The methodology has the ability to take into account alongshore variability in retreat rates, where previously most studies focus upon a single rate for a given shoreline. This paper thereby identifies behaviour based around “switching on”, “no change” and “switching off” in cliff systems. Volumes of sediment released in the twenty first century in response to accelerating sea level rise are likely to be considerable (up to 300 000 m 3 a − 1 ) for the Suffolk study area, and around an order of magnitude above the sediment release estimates for the early twentieth century under lower rates of sea level rise. The implications for shoreline protection offered from additional sediment in the nearshore zone are discussed.

Oyster Reefs as Natural Breakwaters Mitigate Shoreline Loss and Facilitate Fisheries

Shorelines at the interface of marine, estuarine and terrestrial biomes are among the most degraded and threatened habitats in the coastal zone because of their sensitivity to sea level rise, storms and increased human utilization. Previous efforts to protect shorelines have largely involved constructing bulkheads and seawalls which can detrimentally affect nearshore habitats. Recently, efforts have shifted towards “living shoreline” approaches that include biogenic breakwater reefs. Our study experimentally tested the efficacy of breakwater reefs constructed of oyster shell for protecting eroding coastal shorelines and their effect on nearshore fish and shellfish communities. Along two different stretches of eroding shoreline, we created replicated pairs of subtidal breakwater reefs and established unaltered reference areas as controls. At both sites we measured shoreline and bathymetric change and quantified oyster recruitment, fish and mobile macro-invertebrate abundances. Breakwater reef treatments mitigated shoreline retreat by more than 40% at one site, but overall vegetation retreat and erosion rates were high across all treatments and at both sites. Oyster settlement and subsequent survival were observed at both sites, with mean adult densities reaching more than eighty oysters m−2 at one site. We found the corridor between intertidal marsh and oyster reef breakwaters supported higher abundances and different communities of fishes than control plots without oyster reef habitat. Among the fishes and mobile invertebrates that appeared to be strongly enhanced were several economically-important species. Blue crabs (Callinectes sapidus) were the most clearly enhanced (+297%) by the presence of breakwater reefs, while red drum (Sciaenops ocellatus) (+108%), spotted seatrout (Cynoscion nebulosus) (+88%) and flounder (Paralichthys sp.) (+79%) also benefited. Although the vertical relief of the breakwater reefs was reduced over the course of our study and this compromised the shoreline protection capacity, the observed habitat value demonstrates ecological justification for future, more robust shoreline protection projects.

Geotextile tubes as submerged dykes for shoreline management in Malaysia

The shoreline in Malaysia has experienced severe erosion due to the impact of high energy waves, both on the predominantly mud coasts and the predominantly sandy coasts. This perennial process has resulted in the deterioration of the quality of the beach on the sandy coasts and loss of valuable land. Several measures had, in the past, been implemented to mitigate these adverse effects but these had mostly been hard solutions. The application of geosynthetic tubes for shoreline management was introduced in the State of Terengganu on the east coast of Peninsular Malaysia which experiences severe erosion during the North-East Monsoon period. A pilot project, utilising geotextile tubes installed as submerged dykes, was undertaken in 2006 to address the erosion problems and arrest the further erosion of the shoreline at Teluk Kalong, Kemaman, Terengganu. The geotextile tubes comprise of high strength woven geotextile in-filled with sand slurry. Subsequently in 2008, the state implemented a similar shoreline protection project at Pantai Batu Buruk, protecting a 5 km stretch of beach. These works comprise of the installation of 3.5 m diameter geotextile tubes, as submerged dykes, approximately 150 m offshore. The geotextile fabric allows consolidation of the sand to create a long sausage-like gravity structure. Post-installation surveys carried out indicated that the shoreline has improved with much wider foreshore area. Significant sand deposition was also recorded on the foreshore area, which contributes to the long term shoreline management and promoting sustainable protection of the shoreline. This article discusses the concept of shoreline management using geotextile tubes as submerged dykes. The details of these two projects and the outcome of the projects are presented.

How much are the Bolinao-Anda coral reefs worth?

The Total Economic Value of the estimated 200 km 2 of coral reef area straddling the municipalities of Alaminos, Anda, Bani and Bolinao in Pangasinan, Philippines is estimated to reach US$38 million per year consisting mainly of indirect benefits from shoreline protection. Direct use from fisheries, aquaculture, and tourism was valued at US$6 million based on the coral reef interaction index. Non-use values for coral reef conservation were based on estimates of willingness to pay across the three economic sectors plus the general public as a fourth sector. Results varied across sectors and municipalities although the ranges were not wide, especially for fishers. Fishers’ willingness to pay averaged at US$0.25 per individual per year. Except for aquaculture operators in Bolinao, which yielded willingness to pay values reaching US$3 per individual per year, the range of conservation funding was narrow for the three other municipalities for all sectors. Using binary logistic regression (logit model), differences in willingness to pay among fishers are explained by the age, number of children, and employment status.

Design for flooding: architecture, landscape, and urban design for resilience to flooding and climate change

Preface and Acknowledgments. Foreword (Carol Franklin, RLA, FASLA) Foreword (Daniel E. Williams, FAIA). Introduction. PART I: NATURE OF WATER. Chapter 1: Weather. 1.1 Sun and Earth. 1.2 The Atmosphere. 1.3 Weather. Chapter 2: Land and Water. 2.1 Water and Carbon Cycles. 2.2 Biodiversity and the Landscape. 2.3 Follow the Water: The Opportunity for Watershed Planning. Chapter 3: Flooding. 3.1 Flooding from Increased Precipitation. 3.2 Flooding from Severe Storms. 3.3 Economic and Social Costs of Water-Related Natural Disasters. PART II: DESIGN WITH WATER. Chapter 4: The Natural Landscape. 4.1 Understanding the Natural Water Balance. 4.2 When the Water Balance Is Altered. 4.3 Soils and Vegetation. 4.4 Subsurface Water Movement. 4.5 Stream Systems, Wetlands, Riparian Zones, and Floodplains. Chapter 5: The Altered Landscape. 5.1 When the Landscape Is Altered. 5.2 Altered Stream Systems and Increased Flood Damage. 5.3 Why Detention Does Not Solve Flooding. 5.4 Summary: The Natural Landscape as a Model for Resilient Design. Chapter 6: Design for Inland Flooding. 6.1 Resilient Design for Inland Flooding. 6.2 Tools for Watershed Protection. 6.3 Communities and Buildings in Floodplains. PART III: FLOOD-RESISTANT DESIGN. Chapter 7: Flood Design Analysis. 7.1 Definition of Terms. 7.2 Flood Elevation: Base Flood and Design Flood. Chapter 8: The Coast. 8.1 Coastal Processes. 8.2 Shoreline Protection. 8.3 Flood Barriers and Floodgates. 8.4 Summary of Coastal Protection Measures. Chapter 9: Flood Design Practices for Buildings. 9.1 Overview of Flood Design. 9.2 Flood Design at the Building Scale. PART IV: DESIGN FOR RESILIENCE. Chapter 10: Flood-Resistant Design for Sites and Communities. 10.1 Coastal Communities. 10.2 Comprehensive Planning for Resilient Communities. 10.3 Local Actions to Build Community Resilience. Chapter 11: Sea Level Rise. 11.1 Sea Level Rise: The Issues. 11.2 Sea Level Rise: Design Responses. Chapter 12: Design for Resilience. 12.1 The Wave of the Future. 12.2 Models for National and International Action. 12.3 Design Resolution. Epilogue. Glossary. Index.

Distribution of common eiders Somateria mollissima during the brood‐rearing and moulting periods in the St. Lawrence Estuary, Canada

AbstractCommon eiders Somateria mollissima nest in colonies on islands of the St. Lawrence Estuary in Quebec, Canada. After hatching, attending females must reach suitable brood‐rearing habitats while non‐attending females and adult males must find appropriate moulting sites. The aim of our study was to determine the biotic and abiotic factors that influence the distribution of common eiders during the brood‐rearing and moulting periods. We conducted biweekly surveys and recorded the number of ducks by age and sex in 2003 and 2004 at 68 sites along a 200‐km stretch of the south shore of the St. Lawrence River. We further classified adult females according to the presence or absence of young. We evaluated human disturbance during the surveys and developed a sinuosity index describing shoreline protection. We determined the nature of the substrate and an estimate of food abundance for a subsample of sites (N = 38). At the scale of the estuary, common eiders did not distribute randomly but used the same sites in both years. Broods preferred mainland sites near nesting islands. Non‐maternal females and males were located further east along the estuary, but their numbers were lower than expected based on the size of the breeding population, indicating that some birds undertake a moult migration outside of the area. In the eastern portion of our study area, densities of non‐maternal females increased significantly as summer progressed. The distribution of common eiders was influenced by food abundance and type but was not related to our indices of human disturbance and shoreline protection. Males were associated with mussels, non‐maternal females with both mussels and gammarids, while maternal females with ducklings were associated with periwinkles. Few of the sites used by common eiders along the south shore of the St. Lawrence Estuary are currently protected and measures should thus be taken to insure their conservation.

Geotextile sand container shoreline protection systems: Design and application

The use geotextile sand containers (GSCs) as shoreline protection systems, has grown moderately since the first applications in the 1970s. This slow growth can be attributed to two factors; firstly, the lack of understanding of coastal processes and design fundamentals by the larger geosyntheticcommunity in order to provide coastal engineers with suitable solutions, and secondly; there has been very little rigorous scientific wave flume testing with which to analyse the wave stability of geotextile sand containers. The application of geotextile containers in coastal protection works can be traced back to early works carried out in 1970s. The application of these types of structures was somewhat haphazard as very little was understood about the wave stability and durability of the structures. Early wave stability work was carried out Ray (1977) and Jacobs (1983) with small containers, however, the testing programs were limited and did not provide sufficient confidence in the product to carry out exhaustive engineering design. As a result, the technology until recently has relied on manufacturers’ design suggestions based on monitoring of actual structures. Over the past five years, coastal population pressure, extreme events and concerns over climate change and sea level rise have resulted in more emphasis being placed on shoreline protection systems. Geotextile manufacturers have responded to the challenges put forward by design engineers and intensive research has been carried out in the field. This paper outlines the current “state of the art” in terms of the design and specification of geotextile sand containers (GSC). This paper covers the key issues which will ensure the long term integrity of a geotextile shoreline protection system is maintained, these issues include: • Container stability; • Detailed analysis of recent large scale wave flume testing which assess filling capacity, size of container, structure slope and scour protection etc.; • Container/geotextile durability; • Methods and specifications used to limit the effects of the fundamental factors affecting the life span of geotextile containers such as vandal resistance, UV degradation and abrasion resistance etc.

Performance of Experimental Low Volume Beach Fill and Clay Core Dune Shore Protection Project

Abstract An experimental shoreline protection project in Jefferson County, TX was constructed and monitored as part of the National Shoreline Erosion Control Development and Demonstration Program. The project determined the effectiveness of a nontraditional, low volume beach fill at reducing erosion of underlying clay layers and evaluated the performance of a clay core dune compared with that of a sand filled dune. Four cells were constructed on the beach face having 0.18 or 0.25 mm sand and fill volumes of 6 or 12 cy/ft. A fifth control cell had no fill. A 2500 ft long dune was constructed, with half being composed entirely of sand and half being composed of a clay core and sand cap. The project was constructed during the summer of 2004 and was impacted by Hurricane Ivan in September 2004 and later by the same storm as Tropical Storm Ivan in October 2004. An evaluation of profiles and other data taken before, between, and after these storms shows that the clay core dune survived the storms much more inta...

State of California Sensitive Site Strategy Evaluation Program Shoreline Protection Results: 2003–2010

State of California Sensitive Site Strategy Evaluation Program Shoreline Protection Results: 2003–2010

The role of neotectonics in the present day dynamics of the sea coastal zone in the western arctic continental platform areas

Cartographic neotectonic models have been created for the key areas of the coastal sea zone (CSZ) in the Western Arctic. These areas were identified within platforms of different ages. The neotectonics predetermines the most durable component of the CSZ, i.e., a wireframe with a fault block structure, and is one of the principal factors governing its development. In particular, it manifests itself in the difference between the exodynamics of parts of the CSZ, with their morpholithodynamic boundaries being similar to the structural aspect, their lithology being close, and the exposition to sea waves being the same. In predicting the development of the CSZ in the 21st century, one can say that there is a reason for some concern, but not for panic. The results of the investigations performed will assist in developing a more effective concept of shoreline protection and solving other applied and scientific problems associated with the junction zone between land and sea.

The present and future role of coastal wetland vegetation in protecting shorelines: answering recent challenges to the paradigm

For more than a century, coastal wetlands have been recognized for their ability to stabilize shorelines and protect coastal communities. However, this paradigm has recently been called into question by small-scale experimental evidence. Here, we conduct a literature review and a small meta-analysis of wave attenuation data, and we find overwhelming evidence in support of established theory. Our review suggests that mangrove and salt marsh vegetation afford context-dependent protection from erosion, storm surge, and potentially small tsunami waves. In biophysical models, field tests, and natural experiments, the presence of wetlands reduces wave heights, property damage, and human deaths. Meta-analysis of wave attenuation by vegetated and unvegetated wetland sites highlights the critical role of vegetation in attenuating waves. Although we find coastal wetland vegetation to be an effective shoreline buffer, wetlands cannot protect shorelines in all locations or scenarios; indeed large-scale regional erosion, river meandering, and large tsunami waves and storm surges can overwhelm the attenuation effect of vegetation. However, due to a nonlinear relationship between wave attenuation and wetland size, even small wetlands afford substantial protection from waves. Combining man-made structures with wetlands in ways that mimic nature is likely to increase coastal protection. Oyster domes, for example, can be used in combination with natural wetlands to protect shorelines and restore critical fishery habitat. Finally, coastal wetland vegetation modifies shorelines in ways (e.g. peat accretion) that increase shoreline integrity over long timescales and thus provides a lasting coastal adaptation measure that can protect shorelines against accelerated sea level rise and more frequent storm inundation. We conclude that the shoreline protection paradigm still stands, but that gaps remain in our knowledge about the mechanistic and context-dependent aspects of shoreline protection.