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1.
Vietnam’s coastal zone provides a diverse range of natural resources and favourable conditions for social and economic development. However, its coastal ecosystems are highly vulnerable, due to several natural coastal hazards, over-exploitation and other human activities. In spite of diverse interventions, Vietnam’s coastal zone continues to experience significant damage from floods, erosion and typhoons. These hazards are being intensified by climate change and associated rising sea levels. This paper assesses the potential vulnerability of Vietnam’s coast to climate change and discusses possible adaptation policies and plan to reduce the impacts. GIS analysis was used for the assessment of coastal vulnerability. Related literature was reviewed to develop detailed understanding of coastal adaptation to climate change. Adaptation policies and plans were appraised to identify potential coastal adaptation policies and plans that could be adapted by Vietnam. It was identified that vulnerability of the coastal zone of Vietnam could not be attributed only to climatic factors, but also to the physical condition of the coastline. Much of Vietnam’s coastline, particularly, areas around the Red River delta and the Mekong River have elevations below 1 m. These coastlines are largely developed and serve as economic centres of the country, which makes the coast more vulnerable to climate change and the rising sea level. The paper concluded that a non-structural approach (coastal buffer zones, building houses on stilts, storm warning systems, growing of flood-resistant crops and elevated storm shelters with medicine and food storage) could be used by Vietnam to adapt her low-lying coastline around the two deltas to climate change as this strategy enables vulnerable areas to be occupied for longer before eventual retreat. However, for these policies to be successful, it should be planned, implemented well in advance, monitored and evaluated over time.  相似文献   

2.
The Coastal Vulnerability and Exposure Degree (CVED) of the Gran Canaria Island and the coastal risk of Playa de Las Canteras (Las Palmas de G.C.) have been assessed by means of a GIS analysis. The evaluation of coastal vulnerability (H) has been performed by using two different levels of analysis: the first one regarding the entire Island (Coastal Vulnerability Index method - CVI), the second one regarding specifically Las Canteras Beach, selected for its socio-economic importance (Coastal Vulnerability Assessment method - CVA). The application of the CVI method, based on geologic-geomorphologic and meteomarine data easily available, has allowed the regional scale assessment of coastal vulnerability (H) along the Gran Canaria coastline and, therefore, the individuation of more critical coast stretches deserving further analysis. The application of the CVA method, based on more specific morphologic-sedimentary beach features that allow to consider both the beach retreat due to storm surge and the coastal inundation due to run-up on the beach, has provided a large scale detail on the coastal vulnerability of Las Canteras Beach. Socio-economic and damage indexes have been determined for the 15 coastal municipalities included in the study area and, by means of the resulting matrix product, the degree of exposure (Ex) along the Gran Canaria coast has been assessed. Finally, the combination of coastal vulnerability and exposure levels has allowed to obtain the Coastal Vulnerability and Exposure Degree (CVED) for the entire Island and the risk levels that characterize specifically Las Canteras Beach. Major results in terms of CVED highlight prevailing low vulnerability and exposure levels along the western coast, and overall high vulnerability and exposure levels along the eastern coast, from Las Palmas de G.C. to San Bartolomé de Tirajana. The focus made on Playa de Las Canteras has allowed to identify the areas characterized by medium and high risk levels that represent approximately one third (940 m) of the entire beach and are located in its central part. The used two-level analysis approach has proved its efficiency by highlighting the degree of coastal vulnerability along the study coast and, especially, more critical coast stretches (CVI method) such as the Playa de Las Canteras that can be successfully analysed with the CVA approach allowing for a large-scale assessment of risk aspects, essential for a correct definition of priority management strategies. Results obtained with the present study, along with the awareness of the increasing phenomena of coastal erosion and marine flooding arising on the mid-long term due to the effects of global climate change, highlight the need for the competent public administrations of Gran Canaria to develop a strategic approach to coastal management and sustainable development that considers as a whole socio-economic values and natural resources, coastal vulnerability and exposure degree, and risk aspects.  相似文献   

3.
Studies carried out in the NE coastal zone of the State of Pará (Brazil) have recorded, in the last 25 years, numerous evidence of natural impacts of the flood and erosion processes. As a consequence, diverse strategies and measures of population adaptation have been implemented but with limited success. Therefore, in order to subsidize the Coastal Zone Management Program of Pará, this paper aims to identify, assess and classify natural and socio-economic vulnerabilities of this coastal zone by means of a Geographical Information Systems (GIS)-based composite coastal vulnerability index (CVI). In spite of the data problems and shortcomings, using ESRI’s Arcview 3.2 program, the CVI score, to classify, weight and combine a number of 16 separate natural and socio-economic variables to create a single indicator provides a reliable measure of differences (5 classes) among regions and communities that are exposed to similar ranges of hazards. The results are presented in three maps referred to as Natural, Socioeconomic and Total Vulnerability. The confidence associated with the results obtained, the need to utilize another variables, and to frequently update the ones used already were analyzed and discussed.  相似文献   

4.
The Benguela Current Large Marine Ecosystem off southwest Africa is a regionally valued system because of its biological productivity, which supports high biomass throughout the foodweb, and a rich diversity of habitats and species. However, the region is exposed to numerous anthropogenic pressures that are likely to escalate under future economic growth. In response, the Benguela Current Commission called for a spatial biodiversity assessment (BCC-SBA) to identify conservation priorities, including potential areas for marine protected areas. The systematic conservation-planning approach to this assessment requires a fine-scale map of coastal habitats, which was not previously available for the region. Our aim was to undertake this mapping, within tight logistic and resource limitations. We used a previously derived methodology for mapping the distribution of coastal habitats from aerial imagery. The Benguela coast is approximately 5,047 km long. Half of this extent is sandy beach, a third is rocky and mixed shores, 13 % comprises lagoonal features, and the remainder (4 %) comprises estuaries and offshore islands. The distribution and extent of these coastal habitats differs substantially alongshore (i.e. with latitude), with conditions ranging north–south from hot, humid mangrove-lined lagoons, to hyper-arid coastal desert sandy beaches. Patterns in regional geology, climate and oceanography are proposed as the main drivers of spatial heterogeneity in coastal habitat types. The resulting ecological and socio-economic wealth requires proactive protection (supported through the BCC-SBA, for example), to ensure sustainable utilization of the rich natural resources, and persistence of these resources for the benefit of current and future generations.  相似文献   

5.
India has a long coastline of about 7,517 km. with 20% occupying the coastal area. Due to increase in population; people have been exploring the possibility of developmental opportunities in the coastal areas. Tsunami in 2004 was another unexpected natural catastrophe which badly affected many South Indian coastal states especially the state of Tamil Nadu. Coastal communities here are increasingly at risk from many chronic and episodic coastal hazards which threaten the health and stability of coastal ecosystems and communities. The degradation of the coastal environment from chronic human-induced actions threaten food security, livelihoods, the overall economic development and well being of coastal communities. Disasters big or small affecting the coastal communities are reminders that, coastal communities are not resilient to normally recurring hazards. This fact has raised the question of developing community resilience since the most effective approach to reducing the long-term impact of coastal hazards would be to enhance capacities of coastal communities through initiatives which are aimed at ensuring a sustainable recovery in the aftermath of a disaster as well as reducing people’s vulnerability to these disasters. Eight elements of resilience i.e., Governance, Coastal Resource Management, Land Use and Structural Design, Society and Economy, Risk Knowledge, Warning and Evacuation, Emergency Response and Disaster Recovery have been identified which are considered essential to reduce risk from coastal hazards, accelerate recovery from disaster events, and adapt to changing conditions by the affected community. In this paper, all the eight resilience elements have been examined with respect to vulnerability and capacity assessment in selected Tsunami (2004) affected districts in the state of Tamil Nadu, India in order to identify the extent of resilience.  相似文献   

6.
A ‘coastal-hazard GIS’ for Sri Lanka   总被引:1,自引:1,他引:0  
Following the 2004 tsunami disaster in Sri Lanka, it was apparent that mapping the coast’s vulnerability was essential for future protection of the local populations. We therefore developed a prototype ‘Coastal-hazard GIS’ for Sri Lanka so as to provide an effective tool for decision makers to limit the impact of natural coastal hazards such as sea level rise, tsunamis, storm surges and coastal erosion, and thus protect the exposed assets (population, property, settlements, communications networks, etc.). The prototype was developed on a pilot site in Galle through building up homogeneous data on the land/sea interface from studies conducted on the exposure of the coastal populations, the aim being to enable an evaluation of the hazards combined with the vulnerability and thus an analysis of the risks. Coastal risk scenarios are developed so as to estimate the impacts and consequences of an event (tsunami, storm, etc.) on the assets, the principle behind this being that if, in general, the coastal hazard cannot be decreased, then a better knowledge of it through simulation should make it possible to limit the vulnerability and thus the risk. The Coastal-hazard GIS will also provide a planning tool in terms of locating new settlements, expanding urban areas, siting coastal protection works, etc.  相似文献   

7.
8.
Coastal systems are characterized by high geophysical and biophysical sensitivity as being their massive occupation a serious issue concerning their self-regulation. Worldwide coastal areas are exposed to problems such as coastal erosion, degradation and destruction of marine habitats, pollution and rising sea level. Thus, it is crucial to design models of coastal vulnerability assessment to ensure a better management of coastal areas. This study characterizes the vulnerability of the coastal stretch between the beaches of Porto de Mós and Falésia in the Algarve, corresponding to 52?km of the south coast of Portugal. The expansion of urban areas was modelled using a Cellular Automata (CA) based approach. Results show that 65% of the coastal stretch has high and very high vulnerability caused by both physical and human factors. Results further indicate that urban growth may interfere with the natural evolution of the coastal geomorphology. The scenario of urban expansion for the year 2015 highlights the need to develop effective urban planning processes to ensure a correct balance between the geophysical resilience of coastal systems and the promotion of the coastal sector as a strategic asset for the regional and national economy.  相似文献   

9.
Coastal hazards and community-coping methods in Bangladesh   总被引:1,自引:0,他引:1  
Addressing one of the most vulnerable coastal communities in Bangladesh, this paper explores people’s perception and vulnerabilities to coastal hazards. At the same time, it investigates the methods that communities apply to cope with different coastal hazards. Findings revealed that people perceived an increase in both the intensity of hazards and their vulnerabilities. In spite of having a number of socio-economic and locational factors enhancing their vulnerabilities, the community is creating their own ways to cope with these hazards. For different aspects of life like shelter, employment, water supply, and health, communities apply different coping methods that vary with the types of hazard. Efforts have also been made by governments and NGOs to manage coastal hazards. By highlighting both community-coping methods and efforts of development organizations, this paper attempts to devise an integrated approach for managing the coastal hazards that occur in Bangladesh.  相似文献   

10.
A growing awareness of increasing trends in coastal erosion and flooding due to climate change is triggering a demand for the rapid assessment of the potential responses of the coastlines around the world, principally in locations where human occupation is especially endangered. Investigations of present and future physical vulnerability and associated social risk have, therefore, become crucial for coastal management. In order to provide a quick and simple methodology for the identification of vulnerable coastal segments, Sharples (2006) has proposed a mapping methodology, called the smartline approach, which consists of representing, by means of simple lines, a geomorphic classification of the hinterland, backshore and beaches. The aim of this paper is to apply the smartline approach to coastal vulnerability assessment with inclusion of social data. The results show that this methodology is appropriate for the indication of coastal segments with varying degrees of vulnerability to erosion and flooding and for the appraisal of the resulting social risk.  相似文献   

11.
12.
The European Water Framework Directive (WFD) establishes a well differentiated typology of water bodies on the basis of scientific and biological criteria. For coastal waters, such criteria have long been established, while for transitional waters they are still under discussion. One of the difficulties when applying the WFD to coastal lagoons is to include them in only one of these categories, and while there is no doubt about the nature of estuaries as transitional waters, there is some controversy concerning lagoons. To what extent, reference conditions may be similar for estuaries and lagoons, or whether features common to all coastal lagoons are more important for differentiating them from other water bodies than the fact that there is (or is not) any fresh water influence, is something that remains unclear and is discussed in this work. Coastal lagoons and estuaries form part of a continuum between continental and marine aquatic ecosystems. Shelter, strong boundaries or gradients with adjacent ecosystems, anomalies in salinity regarding freshwater or marine ecosystems, shallowness, etc. all contribute to the high biological productivity of estuaries and lagoons and determine common ecological guilds in the species inhabiting them. On the other hand, fresh water influence, the spatial organization of gradients and environmental variability (longitudinal one-dimensional gradients in estuaries versus complex patterns and three-dimensional heterogeneity in lagoons) constitute the main differences, since these factors affect both the species composition and the dominance of certain ecological guilds and, probably, the system’s complexity and homeostatic capability. In the context of the WFD, coastal lagoons and estuaries are closer to each other than they are to continental or marine waters, and, on the basis of the shared features, they could be intercalibrated and managed together. However, coastal lagoons cannot be considered transitional waters according to the present definition. To assume that fresh water influence is an inherent characteristic to these ecosystems could lead to important changes in the ecological organization and functioning of coastal lagoons where natural fresh water input is low or null. In our opinion, the present day definition of transitional waters should be changed substituting the criterion of fresh water influence by another based on common features, such as relative isolation and anomalies in salinity in water bodies with marine influence. Otherwise, coastal lagoons should be considered a particularly characteristic type of water mass for establishing reference conditions of ecological status.  相似文献   

13.
The head Bay region bordering the Bay of Bengal is highly vulnerable to tropical cyclones. Catastrophic risks from storm surge and associated inundation are quite high due to high population density in coastal areas, socio-economic conditions, and shallow bathymetry. It features the world’s largest deltaic system comprising of ‘Sunderbans’ bordered by West Bengal and Bangladesh. In a geomorphologic sense, the head Bay region is a low-lying belt comprising several barrier islands and river drainage systems, numerous tidal creeks, and mud flats having a high risk for widespread inundation. In addition, the high tidal range together with low-lying topography leads to high risk and vulnerability from storm surge inundation. During May 2009, a severe cyclonic storm Aila struck West Bengal causing enormous destruction to life and property along coastal belts of West Bengal and Bangladesh. It was the strongest pre-monsoon cyclone in the past two decades that had landfall in West Bengal. This work reports on a numerical study for hypothetical storm surge and associated inundation from Aila using the ADCIRC model. The study covers a comprehensive qualitative analysis on water level elevation and onshore inundation for West Bengal and Bangladesh regions. The estimated peak storm surge was about 4 m in the Sunderban region that propagated into all major riverine systems, inundating the river banks as well the inland areas. Numerical simulations indicate an average inland penetration distance of 350 m with a maximum of 600 m at various coastal locations in West Bengal and Bangladesh. The study emphasizes the need and importance of inundation modeling system required for emergency preparedness and disaster management.  相似文献   

14.
Coastal barrier environments are heavily influenced by human activities yet there are few examples of landscape ecological work investigating human dimensions of settlement disturbance patterns and processes. We investigated the impacts of residential development on vegetation cover for a remote roadless coastal barrier in Carova, North Carolina that is subject to policies from the federal to local levels and addressed three research questions: How has the region’s the policy history influenced patterns of residential parcel development? What are the spatial and temporal patterns of parcel development? How has development impacted patterns of barrier vegetation cover? We traced the influences of the federal 1982 Coastal Barrier Resources Act (CBRA) designed to discourage development in risky coastal areas as well as state/local coastal policies and employed remote sensing change detection, NDVI analysis and spatial analysis and regression techniques. Results showed an acceleration of new housing structures since 1990, contrary to the intended effects of CBRA. An estimated vegetation cover loss of 437 m2 was associated with each newly developed parcel. NDVI varied along spatial and temporal gradients with more recent development having lower NDVI than older development. Recently developed parcels were larger in area, closer to the beach, and contained houses with larger footprints compared to older developed parcels. Our approach represents a place-based analytical framework for coastal barrier landscapes. Beyond the Carova case study, adopting such an approach coupling natural and human systems for the entire eastern US barrier system requires defining a comprehensive set of coastal barrier spatial units to enable typological classification and subsequent systematic investigation to inform debates regarding coastal ecosystem services and sustainability.  相似文献   

15.
The interactions of physical processes between estuaries and upstream river floodplains are of great importance to the fish habitats and ecosystems in coastal regions. Traditionally, a hydraulic analysis of floodplains has used one- or two-dimensional models. While this approach may be sufficient for planning the engineering design for flood protection, it is inadequate when floodwaters inundate the floodplain in a complex manner. Similarly, typical estuarine and coastal modeling studies do not consider the effect of upstream river floodplains because of the technical challenge of modeling wetting and drying processes in floodplains and higher bottom elevations in the upstream river domain. While various multi-scale model frameworks have been proposed for modeling the coastal oceans, estuaries, and rivers with a combination of different models, this paper presents a modeling approach for simulating the hydrodynamics in the estuary and river floodplains, which provides a smooth transition between the two regimes using an unstructured-grid, coastal ocean model. This approach was applied to the Skagit River estuary and its upstream river floodplain of Puget Sound along the northwest coast of North America. The model was calibrated with observed data for water levels and velocities under low-flow and high-flood conditions. This study successfully demonstrated that a three-dimensional estuarine and coastal ocean model with an unstructured-grid framework and wetting-drying capability can be extended much further upstream to simulate the inundation processes and the dynamic interactions between the estuarine and river floodplain regimes.  相似文献   

16.
《Ecological modelling》2003,169(1):39-60
This paper describes an integrated methodology for the Assessment of Estuarine Trophic Status (ASSETS), which may be applied comparatively to rank the eutrophication status of estuaries and coastal areas, and to address management options. It includes quantitative and semi-quantitative components, and uses field data, models and expert knowledge to provide Pressure-State-Response (PSR) indicators.A substantial part of the concepts underlying the approach were developed as the United States National Estuarine Eutrophication Assessment (NEEA), which was applied to 138 estuaries in the continental United States. The core methodology relies on three diagnostic tools: a heuristic index of pressure (Overall Human Influence), a symptoms-based evaluation of state (Overall Eutrophic Conditions), and an indicator of management response (Definition of Future Outlook).Recently, the methodology has been extended and refined in its application to European estuaries, and a more quantitative approach to some of the metrics has been implemented. In particular, the assessment of pressure is carried out by means of simple modeling techniques, comparing anthropogenic nutrient loading with natural background concentrations, and the quantitative criteria for classification of system state based on different symptoms have been refined to improve comparability.The present approach has been intercalibrated with the original NEEA work, for five widely different U.S. estuaries (Long Island Sound, Neuse River, Savannah River, Florida Bay and West Mississippi Sound) with good results. ASSETS additionally aims to contribute to the EU Water Framework Directive classification system, as regards a subset of water quality and ecological parameters in transitional and coastal waters.  相似文献   

17.
《Ecological modelling》2005,187(4):513-523
Phytoplankton growth in estuaries is controlled by factors such as flushing, salinity tolerance, light, nutrients and grazing. Here, we show that biodiversity of estuarine phytoplankton is related to flushing, and illustrate this for some European estuaries.The implications for the definition of reference conditions for quality elements in estuaries of different types are examined, leading to the conclusion that constraints on the number of estuarine and coastal types that may be defined for management purposes require that quality classes take into account natural variability within types, in order to be ecologically meaningful. We develop a screening model to predict the growth rate required for a phytoplankton species to be present under different flushing conditions and apply it to estuaries in the EU and US to show how changes in physical forcing may alter biodiversity. Additional results are presented on the consequences for eutrophication, showing that changes in residence time may interact with species-specific nutrient uptake rates to cause shifts in species composition, potentially leading to effects such as harmful algal blooms.We discuss applications for integrated coastal zone management, and propose an approach to normalization of estuarine phytoplankton composition as regards species numbers.  相似文献   

18.
This paper demonstrates the effectiveness of integrating GIS and modern spatial data for the development of a detailed geomorphic classification of the Bulgarian Black Sea coast. This classification is important for the precise measurement of various natural and technogenous (engineered) coastline types and serves as a basis for identification of the areas with high exposure to different coastal hazards. To illustrate potential uses of this simple methodology, a map of the potential coastal erosion/cliff retreat hazard for the Bulgarian coast was produced from this GIS database. Several types of data were used: high resolution orthophoto, topographical maps in 1:5,000 scale and geological maps. Geomorphic classification utilized both geomorphological and engineering criteria. A total of 867 segments were delineated along the coast. Four hundred sixty five were classified as natural landforms (cliffs, beaches, river mouths) with a total length of 362,62 km and 402 were indicated as technogenous segments (port and coast-protection structures, artificial beaches) with a total length of 70 km. Based on the geologic materials present at each segment and cliff height, the cliffed portions of the Bulgarian coast were classified for expected erosion rates, and therefore, hazard vulnerability: low hazard (volcanic type cliff); moderate hazard (limestone type cliff) and high hazard (loess and clayey types cliff). This “predictive model” was then compared to a previously published field study of coastal erosion rates to validate the model. As a result, a new high quality, but qualitative data for Bulgarian coastal bluff/cliff erosion were obtained, incorporated and analyzed in GIS.  相似文献   

19.
The global change currently observed is deemed to generate accelerated coastal erosion and an increase in frequency and intensity of extreme weather events. Populated tropical island coasts are particularly vulnerable. Awareness of this vulnerability has prompted recourse to the construction of operational observatories on the coastal dynamics of several French tropical islands, including Mayotte. The aims of this initiative are to characterise the coastal morphology of tropical islands and to monitor their rhythms and mechanisms of evolution, adaptation and resilience in the face of extreme climate and wave events (cyclones, storms, surges, strong swells…). Based on this, appropriate defence and/or adaptation strategies can be developed and implemented. Mayotte Island is a fine example of the implementation and utility of such an observatory. The island, in the southwest Indian Ocean, is characterised by a highly diversified coral reef-lagoon complex comprising pocket beaches and mangroves subject to increasing pressure from strong island demographic growth. The operational observatory set up on the island incorporates a Geographical Information System (GIS) based on a network sourced by various field measurements and observations conducted on the coastal forms on the basis of a predefined protocol and methodology. Field experiments include hydrodynamic measurements, topographic surveys, and observations, and these are coupled with the analysis of aerial photographs and regional meteorological data in order to gain a better understanding of the coastal morphology and of the evolution of the reef-lagoon complex. The results fed into the observatory and analysed through the GIS provide interactive maps of the coastal landforms and their evolution and dynamics over various timescales. Within a local framework of strong socio-economic and demographic pressures, and a more global context of environmental change, this observatory should lead to a better understanding and prediction of the morphodynamics of the coast of Mayotte, while providing data to the public at large, to researchers, and to stakeholders involved in decision-making in the face of the major and rapid environmental and socio-economic changes liable to affect the fragile reef-mangrove systems and pocket beaches.  相似文献   

20.
In the rapidly growing coastal megacities of developing and emerging countries, the implementation of new sewage treatment facilities is often not keeping pace with the enormous population growth, leading to a deterioration of the urban water resources. Only very few studies discuss faecal water contamination in these urban areas. Our study area Jakarta, the capital of Indonesia, is such a megacity. We investigated chemical markers of faecal contamination in water and sediments from the rivers and canals flowing through Jakarta. Moreover, also the spatial distribution of faecal markers in Jakarta Bay, the coastal ecosystem that receives all urban river discharges, was assessed. The concentrations of the faecal steroid coprostanol in river water ranged from 0.45 to 24.2 µg L?1, and in sediments from 0.3 to 400 µg g?1, reflecting the problem of inadequate sewage treatment capacities in the city. The steroid distribution in Jakarta Bay in May 2013 as compared to dry season data indicates a flushing out of particle-associated pollutants from the urban rivers far offshore during the precedent rainy season, where the city experienced a severe flood. This flushing out of particle-associated pollutants during times of heavy rainfall as observed in our study is a pollutant transport mechanism that is important for all tropical coastal systems. The associated impacts on sensitive coastal habitats might become more severe in the future, as a consequence of the expected climate change effects on monsoon variability.  相似文献   

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