Sea-level rise and coastal vulnerability: an assessment of Andhra Pradesh coast,India through remote sensing and GIS

The eustatic sea-level rise due to global warming is predicted to be about 18 to 59 cm by the 2100 (IPCC 2007), which necessitates identification and protection of vulnerable sections of coasts. Assessment of vulnerability level of Andhra Pradesh (AP) coast as an example is demonstrated in this study using five physical variables, namely coastal geomorphology, coastal slope, shoreline change, mean spring tide range, and significant wave height. A coastal vulnerability index was prepared by integrating the differentially weighted rank values of the five variables, based on which the coastline is segmented into low-, moderate-, high-, and very high risk categories. About 43% of the 1,030-km-long AP coast is under very high-risk, followed by another 35% under high-risk if the sea level rises by ~0.6 m displacing more than 1.29 million people living within 2.0 m elevation in 282 villages in the region.     

Geosynthetics in protection against erosion for river and coastal banks and marine and hydraulic construction

Geosynthetic products offer owners, engineers, and contractors a safe and economical solution to everyday engineering challenges and construction requirements. Used as replacements to natural materials, geosynthetic products include a wide range of functions such as filtration, drainage, separation and reinforcement requirements. The wide range of geosynthetic use includes landfill caps and base liner applications, environmental protection under roads and railways, containment structures, dams, canals, ponds, rivers and lakes, coastal and offshore protection. However, their potential in other applications is only limited by convention. With the use of geosynthetics, most geotechnical structures can be improved and the design lifetime can be dramatically increased. Additionally new modern design approaches are often only possible with the use of geosynthetics. Because of the strong development of the various industries all around the world the development and challenge of the use of geosynthetics in geotechnical, hydraulic, coastal and offshore engineering should be of special interest. Based on engineering approaches and installed projects, this paper will cover the state-of-the-art of geosynthetics use in environmental applications, as well as in hydraulic, coastal protection and offshore engineering structures and also discuss the benefits of geosynthetics to modern building technology.     

Soft copy photogrammetry to measure shore platform erosion on decadal timescales

Shore platform erosion is considered a driving mechanism for cliff recession on many rocky coasts and, in the vicinity of sea defence structures, a threat to their stability, yet the spatial pattern of platform erosion, as well as the rate of lowering, is poorly documented. Measurements based on techniques such as the micro-erosion metre or laser scanner, though highly accurate for short time scales and specific locations, are difficult to extrapolate in space and time. They also fail to record mesoscale changes such as block removal. This paper describes a technique to quantify spatial and temporal changes and presents first results.     

江苏近岸海域富营养化现状评价与成因分析

应用综合污染指数法和富营养化指数法评价了2010年度江苏近岸海域水质状况。结果表明,50%的海水水质测点已显现出不同程度的富营养化迹象;影响江苏近岸海域的首要污染物为无机氮和活性磷酸盐,二者污染分担率之和近50%;现阶段造成江苏近岸海域水体富营养化的主要因素来源于入海河流和直排海污染源的氮磷输入,与"十五"末相比,全省主要入海河流TN排放量增长约284%,TP排放量增长约451%。     

Ecosystem classification for EU habitat distribution assessment in sandy coastal environments: An application in central Italy

Many recent developments in coastal science have gone against the demands of European Union legislation. Coastal dune systems which cover small areas of the earth can host a high level of biodiversity. However, human pressure on coastal zones around the world has increased dramatically in the last 50 years. In addition to direct habitat loss, the rapid extinction of many species that are unique to these systems can be attributed to landscape deterioration through the lack of appropriate management. In this paper, we propose to use of an ecosystem classification technique that integrates potential natural vegetation distribution as a reference framework for coastal dune EU Habitats (92/43) distribution analysis and assessment. As an example, the present study analyses the EU Habitats distribution within a hierarchical ecosystem classification of the coastal dune systems of central Italy. In total, 24 land elements belonging to 8 land units, 5 land facets, 2 land systems and 2 land regions were identified for the coastal dunes of central Italy, based on diagnostic land attributes. In central Italy, coastal dune environments including all the beach area, mobile dunes and all the fixed-dune land elements contain or could potentially hold at least one EU habitat of interest. Almost all dune slack transitions present the potentiality for the spontaneous development of EU woodlands of interest. The precise information concerning these ecosystems distribution and ecological relationships that this method produces, makes it very effective in Natura 2000 European network assessment. This hierarchical ecosystem classification method facilitates the identification of areas to be surveyed and eventually bound, under the implementation of EU Habitat directive (92/43) including areas with highly disturbed coastal dune ecosystems.     

近岸海域区域环境质量综合评价体系构建及应用实例

建立了适用于我国现阶段海洋环境质量监测现状的基于水、沉积物和生物三大介质污染状况的近岸海域海洋环境质量综合状况评价体系,包括评价指标体系的选择、评价及等级分级标准的确定、评价流程的确定等内容。用所建立的综合评价体系对锦州湾海域进行了评价,评价结果表明,锦州湾海域总体状况较差,受到了严重污染,与锦州湾海域的实际污染状况相符,验证结果表明了该综合评价体系的适用性。     

Land-use and agriculture in Denmark around year 1900 and the quest for EU Water Framework Directive reference conditions in coastal waters

The EU Water Framework Directive (WFD) aims to protect the ecological status of coastal waters. To establish acceptable boundaries between good and moderate ecological status, the WFD calls for reference conditions practically undisturbed by human impact. For Denmark, the nitrogen (N) concentrations present around year 1900 have been suggested to represent reference conditions. As the N load of coastal waters relates closely to runoff from land, any reduction in load links to agricultural activity. We challenge the current use of historical N balances to establish WFD reference conditions and initiate an alternative approach based on parish-level land-use statistics collected 1896/1900 and N concentrations in root zone percolates from experiments with year 1900-relevant management. This approach may be more widely applicable for landscapes with detailed historic information on agricultural activity. Using this approach, we find an average N concentration in root zone percolates that is close to that of current agriculture. Thus, considering Danish coastal waters to be practically unaffected by human activity around year 1900 remains futile as 75% of the land area was subject to agricultural activity with a substantial potential for N loss to the environment. It appears unlikely that the ecological state of coastal waters around year 1900 may serve as WFD reference condition.     

Coastal issues for oceanic islands: implications for human futures

Compared to continental areas, most islands have exceptionally long coastlines relative to their total land area. For this reason, islands are uncommonly vulnerable to problems associated with coasts. The future of the human inhabitants of many island states depends intrinsically on the sustainable management of their coasts, a challenge which grows more pressing as island populations increase and the associated demands on island coastlines change and grow. These issues are presented and discussed in this article. The mechanics of the sustainable management of island coasts is itself an important issue. At the national or local level, management is plagued by problems of insufficient and/or imprecise data and understanding that may lead to inappropriate solutions that even exacerbate the problems they are intended to solve. At an inter-governmental or international level, problems associated with the understanding of island environments need to be resolved before optimal management strategies can be developed. This article presents a brief explanation of the nature of coastal vulnerability on oceanic islands, followed by a discussion of several key problems associated with their sustainable development and the role of human and non-human factors in recent environmental change. It discusses the future of oceanic island coasts in the face of both internal and external threats to their sustainable management. It concludes with a blueprint for their survival.     

Use of Ammophila arenaria for Dune Stabilization in South Africa and Its Current Distribution—Perceptions and Problems

Ammophila arenaria (marram or European beach grass) for dune stabilization in South Africa in the past and present, its present distribution in South Africa, and the perceptions of coastal management agencies and the public about its further use. The planting of A. arenaria became the most important means of dune stabilization, by human intervention, along the South African Cape coast in this century. Its modern distribution from the semiarid west coast to the subtropical shores of the Eastern Cape extends through various climatic zones. Although historical data are missing for some areas, there is no indication of its unaided spread. A. arenaria occurs at most sites because of its prior planting. The South African climate appears to affect its vigor. However, concern about the use of the alien grass has been raised since it has proved to be a highly invasive species in other parts of the world, particularly along the North American west coast and in Tasmania. While the CSIR (Council of Scientific and Industrial Research) promotes its use, CNC (Cape Nature Conservation) follows a policy that restricts the use of any alien plant, including A. arenaria, and requests further research on its invasive properties. Although a questionnaire survey shows that stabilization sites featuring large areas of A. arenaria are accepted by the South African public, current coastal management practices need to be analyzed critically. A thorough investigation of the potential invasiveness of A. arenaria on South African coastal dunes will be essential and shed new light on the American A. arenaria problem.     

Morphodynamic responses of nourished beaches in SW Spain

Coastal erosion in SW Spain is affecting man-made structures and beaches that represent an important economic resource in the area. In the last decade the Spanish government carried out several nourishment works that have limited durability. Most of the artificial beach fills consist of a spill of natural dredged sand on the visible beach, leading to a flat, artificial berm with an important seaward slope and narrow foreshore. As a result, the initial dissipative profile was transformed into a fully reflective one. A beach monitoring program was carried out to record morphological evolution after the nourishment works. Several field assessments of disturbance depth were also made to characterize beach morphodynamics of a nourished beach (Rota) and a natural dissipative one (Tres Piedras), whose slope was similar to the pre-nourishment gradient of Rota beach. Natural dissipative beaches were characterized by spilling breakers that did not significantly affect bottom sand. The severe erosion recorded in the nourished zones was related to the new morphodynamic regime acting on these beaches, which was controlled by high erosive plunging breakers associated with high foreshore slopes. In conclusion, other nourishment practices should be used, better adapted to the natural beach morphodynamics of the zone, taking also into account the original grain size and density of the beach sands, in order to obtain more durable artificial beaches.