中国海岸侵蚀治理和海岸保护

加强海滩和海岸侵蚀的研究，组织建筑用砂资源的调查，进一步完善海洋环境保护法或制定海岸环境保护法以便制止不合理的采砂和保护沿岸单位和居民的合法权益，使出现环境问题后的赔偿有确定保证，防止人工海岩进一步扩大，发展偏僻海岸地区的发候旅游，让沿岩居民能从保护海岩中得到实际利益，以便使我国海岸侵蚀治理和海岸保护达到一个新水平。     

中国砂质海岸分布特征与存在问题

中国东部砂质海岸分布范围广泛,地形发育多样,风沙灾害、海岸侵蚀等地质灾害问题多发,严重影响了沿海地区的社会经济发展。了解沙质海岸的分布特征,做好砂质海岸的研究防护工作,对促进海洋经济持续稳定的发展有着十分重要的作用。     

Remote sensing of coastal interactions in the Mediterranean region

The coastal regions of the Mediterranean are the site of countless economic and recreational activities, but are threatened by dramatic dangers of misuse and pollution. Adequate tools are needed to study the environmental pressure imposed on these regions by the conflicting needs of protecting their ecological balance and exploiting their natural resources. Coastal ecosystems are very sensitive to the environmental impact of land use in watersheds, along the coast and further inland, of fluvial discharges, and of marine processes. Weathering, erosion, or waste disposal on land, as well as other activities at sea, such as shipping, dumping or oil extraction, are but a few of the factors which would require that the coastal areas be suitably monitored. Modern techniques of environmental assessment call for the use of integrated observation systems. The collection of data with traditional coastal installations remains an important component of such research. However, the large space scales and short time scales of many near-coastal and/or marine processes require the use of (orbital) remote sensors. In particular, optical sensors, operating in the visible/infrared spectral region, have shown their usefulness for providing novel information on physical, geo-chemical and biological processes of the coastal area. Optical remote sensing of the coastal zone finds applications in studies of land use, surface cover, hydrology and coastal ecology at large; of water quality and sediment transport, coastal runoff and circulation, or dynamical processes (looking, e.g., at the evolution of pigment and/or temperature patterns, and their distribution as related to plankton dynamics, currents or river plumes); as well as in those of energy transfer, carbon cycling and climatology in general. Selected applications of optical observation techniques in the Mediterranean region, conducted in the framework of international demonstration programmes (i.e. the Ocean Colour European Archive Network, OCEAN, Project), provide examples of the remote sensing potential in the field of integrated coastal/marine environmental management.     

Application of a Biological Tool for Estimating Current Annual Rates of Erosion and Deposition in Modern Coastal Environments: A Case Study in the Bay of Bengal Coast

The marine polychaete Diopatra cuprea (Bosc) produces tubes that protrude above the sediment surface. To the part above the sediment surface the worm attaches foreign particles. A sharp boundary separates the parts above and below the sediment surface. With subsequent erosion, part of the tube without attached particles becomes exposed and this exposed part indicates the amount of erosion. With subsequent sedimentation, the tubes are enlarged upward and the sharp boundary is found below the sediment surface indicating the amount of subsequent sedimentation. This mode of construction of tubes during an average life span of two years renders tubes as simple but excellent natural tools for precise and easy measurement of the latest annual rates of erosion and deposition in coastal areas, data that are essential for the solving of coastal engineering and geoenvironmental problems. Comparison of this tool with expensive long-term coastal profiling data in four areas in the Bay of Bengal coast indicates its correctness and high applicational value.

This revised model can be applied to modern coastal environments only for calculating latest annual rates of both erosion and deposition as correctly as latest physical techniques. Being based on the similar organosedimentary principle, it distinctively contrasts with the earlier model of Myers which provides information on the amount of sediment accumulation only without any time connotation and, it may generate erroneous results if applied to the geologic past unless some limitations evolved in the processes of dewatering, compaction, lithification and diagenesis are removed.     

Application of a Biological Tool for Estimating Current Annual Rates of Erosion and Deposition in Modern Coastal Environments: A Case Study in the Bay of Bengal Coast

The marine polychaete Diopatra cuprea (Bosc) produces tubes that protrude above the sediment surface. To the part above the sediment surface the worm attaches foreign particles. A sharp boundary separates the parts above and below the sediment surface. With subsequent erosion, part of the tube without attached particles becomes exposed and this exposed part indicates the amount of erosion. With subsequent sedimentation, the tubes are enlarged upward and the sharp boundary is found below the sediment surface indicating the amount of subsequent sedimentation. This mode of construction of tubes during an average life span of two years renders tubes as simple but excellent natural tools for precise and easy measurement of the latest annual rates of erosion and deposition in coastal areas, data that are essential for the solving of coastal engineering and geoenvironmental problems. Comparison of this tool with expensive long-term coastal profiling data in four areas in the Bay of Bengal coast indicates its correctness and high applicational value. This revised model can be applied to modern coastal environments only for calculating latest annual rates of both erosion and deposition as correctly as latest physical techniques. Being based on the similar organosedimentary principle, it distinctively contrasts with the earlier model of Myers which provides information on the amount of sediment accumulation only without any time connotation and, it may generate erroneous results if applied to the geologic past unless some limitations evolved in the processes of dewatering, compaction, lithification and diagenesis are removed.     

The role of coastal setbacks in the context of coastal erosion and climate change

Coastal erosion and storms represent a source of risk for settlements and infrastructure along the coast. At the same time, coastal natural assets, including landscape, are threatened by increasing development mainly driven by tourism. The Mediterranean coast is especially vulnerable to these processes, considering its high biological and cultural diversity. An additional challenge is represented by climate change, as it will force coastal communities to apply more or less drastic adaptation strategies. Coastal setbacks, used to protect coastal communities and infrastructure from storms and erosion, and to preserve coastal habitats and landscapes from degradation, is one of the main instruments suggested by the Protocol on Integrated Coastal Zone Management of the Barcelona Convention, entered into force on the 24 of March 2011. Its implementation has the potential to influence coastal policies in other regions, such as the neighbouring Black Sea.The CONSCIENCE project has formalized concepts and conducted specific studies to provide new tools for coastal erosion management practice. The objective of this paper is to present a synthesis of the research conducted into coastal setbacks for coastal erosion management and climate change adaptation. This is done by analysing the requirement of the Protocol, current processes and management practices in two case study areas (Costa Brava Bays in Spain and Danube Delta, in Romania) and the new challenges posed by climate change.     

Geomorphic setting and geohazard-related features along the Ionian Calabrian margin between Capo Spartivento and Capo Rizzuto (Italy)

The aim of this work is to describe the morpho-dynamic processes of coastal and submarine areas based on morpho-bathymetric data and sub-bottom acoustic profiles from the Calabrian Ionian margin (from Capo Spartivento to Capo Rizzuto). We describe some of the most significant geo-hazard features and show some examples of their complex interactions and related potential risk. The relationship between these geo-hazard features and the active tectonics and some severe historical earthquakes and tsunamis is also discussed. The studied area is characterized by several well developed canyon systems. The retrogressive erosion of the canyon heads affects the continental shelf and interacts with the coastal morpho-sedimentary processes, evidencing the intense geomorphic activity of this sector of Ionian margin. The widespread evidence of mass wasting processes and slope instability, together with the historical seismicity, makes this area also an ideal case study for investigating on the possible relationship between earthquakes and landslide-triggered tsunamis and assessing the potential risk.     

Seafloor mapping for geohazard assessment: state of the art

During the last two decades, increasing use of full-coverage sonic mapping of the seafloor has made us more aware of the large and different number of seafloor processes and events bearing significant geohazard potential. This awareness combines with the increasing use of the seafloor for infrastructure and with the high density of population and settlement on the coast. Seafloor mapping is the first step in making a census of the geohazard-bearing features present in a given offshore area. It often provides the only tool for a comprehensive, although non-specific, seafloor geohazard assessment over large areas that are scarcely groundtruthed by acoustic prospection and seafloor sampling. However, the characterization of geohazard features on a morphological basis alone is limited, and more detailed investigations are needed to define the character and state of activity of potentially hazardous features. Such investigations include the use of deep-tow or autonomous platforms designed to acquire high-resolution data at depth as well as in situ measurements, both being very expensive activities not applicable over large areas. Thus seafloor mapping is often not only the first and the main but also the only tool for a comprehensive seafloor geohazard assessment. This special issue represents an example of the diversity of approaches to seafloor geohazard assessment and summarizes the present state of this discipline. Both the diverse technologies applied and the specific aims of offshore geohazard assessment brought different communities to deal with the study of seafloor processes and events from remarkably distinct viewpoints. We identified three end members in offshore geohazard assessment: (1) geohazard assessment ??sensu stricto??, (2) ??engineering?? geohazard assessment, (3) ??non-specific?? geohazard assessment. These are being conducted by industry, academia and public agencies in charge of civil protection and land-use planning and management. Understanding the needs and geohazard perception of the different groups is a necessary step for a profitable collaboration in such an interesting and rapidly developing field of marine geology.     

Distribution and thickness of sedimentary facies in the coastal dune, beach and nearshore sedimentary system at Maspalomas, Canary Islands

Numerous studies have shown that most beaches and coastal dune systems of the world are currently eroding but very few have investigated the combined sediment budgets of subaerial and nearshore submarine systems. In the case of the dune field of the Maspalomas Natural Special Reserve (in the south of Gran Canaria), the adjacent Maspalomas and El Inglés beaches and the adjacent submarine platform, the sediment budgets have been severely affected by erosion over the past few decades. The objectives of this study were to investigate the availability of sand within the modern sedimentary system, including the coastal dunes, the beaches and the submerged shelf, but also to assess local sediment sinks. An isopach map generated on the basis of topo-bathymetric data and seismic-reflection profiles revealed that sediment thickness varies from 0–22 m in the study area. Expanses of relatively low sediment thickness were identified in the south-western sector of the coastal dune field along Maspalomas beach, and in the nearshore region to the south of this beach. These localized sediment-deficit areas earmark Maspalomas beach as the most vulnerable shore strip threatened by erosion. The shallow seismic data also revealed that the submarine platform south of Maspalomas represents a marine terrace cut into an ancient alluvial fan, thus documenting an influence of the geomorphological heritage on the present-day morphodynamics. A side-scan sonar mosaic of this nearshore platform enabled the delimitation of areas covered by rock, boulders and gravel, vegetated sand patches and a mobile sand facies, the latter including ripple and megaripple fields. The megaripple field in a valley close to the talus of the marine terrace has been identified as a major sediment sink of the Maspalomas sedimentary system. It is fed by south-westerly storm-wave events. The sediment deficit in the coastal dune field and along Maspalomas beach can therefore only be explained by a currently faster loss of sediment to an offshore sink than can be compensated by the supply of sand from outside the system.     

Regional-scale seafloor mapping and geohazard assessment. The experience from the Italian project MaGIC (Marine Geohazards along the Italian Coasts)

Recent developments in seafloor imaging and mapping techniques greatly improved our capability of identifying marine geohazards affecting continental margins. Geomorphic features can be detected in great detail by high-resolution multibeam imaging and regarded as geohazard indicators; the most common include slide scars and deposits, canyon headscarps and steep erosional flanks, fault-related seafloor unevenness, mud volcanoes, pockmarks, gravity flow deposits, erosional scours and bedforms indicating sediment mobility at diverse temporal/spatial scale. These processes are widespread on Italian continental margins and are potential indicators of geohazard for human settlements and infrastructures in the offshore and coastal zones. The national Project MaGIC (Marine Geohazards along the Italian Coasts) aims at documenting potential geohazards based on the acquisition of high-resolution multibeam bathymetry and on the production of maps of the geohazard-related geomorphic features for most of the Italian continental margins. With reference to this issue, we discuss some of the most frequent problems dealing with reconnaissance, interpretation and cartographic representation of geohazard-related geomorphic features at a regional scale.     

珊瑚礁海岸侵蚀的研究方法

珊瑚礁海岸海滩和礁坪是海岸作用是活跃的部分，也是近几十年来与海岸发育，海岸侵蚀联系最密切的部分，这一部分高潮时被淹没，低潮时完全出露或大部分出露，使得在此进行地质填图成为可能，这样的地质图可以提供许多信息，如沉积物粒度分布规律，沉积物来源和搬运方向，海滩岩所指示的古海岸线位置，人类活动特别是海岸工程对沉积物分布的影响以及海岸线的变化过程和趋势，在礁坪上开挖的人工水道内测流，能够了解水流的性质以及是否有足够的速度搬运沉积物，从而了解人工水道对海岸的影响和预测海岸的状态，这些方法也可以用于大陆泥质和砂质第岸侵蚀的研究。     

Sea-level, sediment supply and coastal changes: Examples from the coast of Ireland

Sediment supply and pre-existing shoreline morphology are crucial factors in controlling coastal changes due to sea-level rise. Using examples from both southeast and northeast Ireland, it can be shown that sea-level change may trigger a sequence of events which leads to both static and dynamic shoreline equilibrium. Cliff erosion and longshore sediment movement in east Co. Wexford has led to injection of sediment onto the shelf, and the growth, under both wave and tide regimes, of linear offshore shoals. These shoals now control the pattern of shoreline erosion and provide a template for possible stepwise evolution of the coast under any future sea-level rise. In contrast, the nearby coast of south Co. Wexford comprises a series of coarse clastic barriers moving monotonously onshore, via overwash processes. Here the behavior of the barrier is conditioned by the antecedent morphology of both the beach face and stream outlet bedforms. Finally, the rock platform coast of Co. Antrim presents a far more resistant shoreline to incident marine processes, yet even here there is strong evidence of present process control over so-called ‘raised’ platforms and embayments. It is concluded that coastal sediment supply and dynamics, together with coastal morphology and its interaction with waves, present a far more complex variety of sea-level indicators than is normally acknowledged.     

天津海岸基本功能划分初探

随着我国外向型经济战略深入实施,海洋资源及其区位优势成为了决定工业化进程的重要因素.重化工布局和人口进一步向沿海地区聚集成为经济发展必然趋势,而海岸地区是生态环境的脆弱区域,因此,必须通过确定海岸区域的基本功能,来引导海岸区域保护与开发活动,以实现经济、社会和生态效益最大化.以天津市为例,分析了海岸开发利用存在问题.在...     

厦门吴冠海蚀地貌的地学意义及利用探讨

吴冠岸段是厦门为数很少的自然海岸之一,保留着该地区少见的有规模的花岗岩海蚀地貌景观．考察发现,该段海岸有海蚀崖、海蚀穴、海蚀平台、海蚀洞、海蚀拱桥、海蚀蘑菇等海蚀地貌类型,以及众多形态逼真、造型生动的象形石景观．资料显示,半封闭海湾内成规模的海蚀地貌较少罕见,吴冠海蚀地貌对于研究小风区作用下的基岩海岸动力地貌特征具有重要的地学意义;对于研究全新世构造运动、全新世海平面变化等具有重要的科研、科普价值．该海蚀地貌作为区域性的稀缺地学景观资源,还具有很高的景观美学、旅游资源价值．应将其作为自然历史遗迹及时加以保护,并在保护的基础上充分发挥其地学旅游资源价值．可通过肖形策划与艺术设计、提升科技和文化内涵、修复其南侧受损沙滩、融合区域旅游资源等措施,建成融美学景观旅游、科技和文化旅游、休闲娱乐旅游为一体的地学旅游景区．     

Deposits of the 1983 and 1993 tsunamis on the coast of Primorye

Deposits of the two strongest tsunamis of the 20th century have been found on the eastern coast of Primorye. The tsunamis had epicenters in the Sea of Japan west of the coast of Hokkaido. The distribution and preservation of deposits in bays of different geomorphological structure have been analyzed. The best defined sedimentary covers occur in the upper part of sections in low-lying areas of bay shores, where the wave runup was more than 3 m. The best preserved deposits have been observed in bays attributed to loworder streams. Variations of the structural composition of tsunami deposits formed by traction processes associated with the tsunamis have been analyzed depending on distance from the shoreline; the sources of material have been identified. Tsunami waves transported sand not only from beaches, ancient storm ridges, and terraces, but also from the underwater coastal slope; waves also grabbed material from estuarine lagoons and lakes located in the shore inundation zone. Deposits include marine diatoms with dominant sublittoral planktonic and benthic species, which suggests that the material was transported from a depth no more than 15 m. Deep-sea species of diatoms and their fragments have been encountered. Among freshwater diatoms are species with different ecological identities, indicating erosion and redeposition of material transported from various sources.     

海平面上升对中国沿海地区影响初析

近五十年来中国沿岸海平面变化总的呈上升趋势，年变率平均为１．４ｍｍ／ａ，中国沿岸地形复杂，未来海平面上升可能影响的主要脆弱区为黄河、长江和珠江三大三角洲和滨海平原，其可能受害区域估计达３５０００ｋｍ＾２。影响中国沿岸相对海平面上升的主要因素有：近代地壳垂直运动和地面沉降，台风和风暴潮，海岸侵蚀和海咸水入侵等。     

Anticipate response of climate change on coastal risks at regional scale in Aquitaine and Languedoc Roussillon (France)

LIFE Environment/RESPONSE project (2003–2006) aimed to evaluate and map, at regional scale, the impact of climate change on coastal risks (erosion and marine flooding), by anticipating the response to regional climatic change scenarios of coastal systems. These are described by their geomorphology, coastal processes, known hazardous events and existing defences. Application on Aquitaine and Languedoc Roussillon regions (France) assesses the likely increase of the coastal risks. In both regions, the weight of geomorphology and settlement development is underlined. The results point out the need for better knowledge on physical resilience capacity of the coast, assets values and vulnerability, and the urge of an integrated management approach of coastal risk, at least at the scale of sedimentary cell.     

辽宁省海岸的蚀淤等级与分布

为了查清辽宁省海岸的蚀淤等级和分布,从1990年和2007年遥感图像中提取了17年的岸线变化信息,结合辽宁省908专项海岸带海岸侵蚀特征的调查资料,对全省海岸蚀淤情况进行了等级划分,并对其形成原因进行了分析与评价。结果表明,砂质海岸侵蚀较重的区域主要分布在绥中和熊岳一带,黄海岸段的砂质海岸基本稳定,基岩海岸侵蚀较重的区域主要分布在老铁山一带,粉沙淤泥质海岸侵蚀较重的区域分布在庄河一带。摸清辽宁省海岸蚀淤等级分布,对海岸整治与修复、海岸侵蚀灾害的防治与防护以及海岸带管理具有一定的指导意义。     

Perspectives of the coastal and marine fisheries of the Bay of Bengal,Bangladesh

Bangladesh has vast coastal and marine resources along its south edge. Due to the geographical position and climatic condition, the coastal area of the country is known as one of the highly productive areas of the world. Bangladesh is rich not only in terms of its vast water areas but also in terms of the biological diversity. One of the unique features of the coastal areas is the influence of the mangrove forests, which support a high number of fishes and other commercially important aquatic organisms. The biological and ecological values of the Bay of Bengal have been pointed out by many authors. The coastal and marine fisheries have been playing considerable roles not only in the social and economic development of the country but also in the regional ecological balance. A large number of commercially important fishes have long been exploited which are of high export values. Shrimp aquaculture has become a highly traded export-oriented industry for the last few decades. In spite of having bright prospects, marine aquaculture on a commercial basis as well as marine stock enhancement and sea ranching are yet to be developed. The marine fisheries sector has been suffering from chronic disintegration and mismanagement that have led to many consequences. Most of the commercially important fish stocks are either overexploited or under threat. Marine pollution has reached a level that could create an unmanageable situation in the near future; coastal shrimp farming has generated considerable debates due to its adverse environmental and socioeconomic impacts. The Bay of Bengal and its coastal areas are one of the most poorly studied areas of the world although it possesses high potential for further stock improvement. Proper attention is needed in every aspect of exploitation, handling and processing, export and marketing as well as in biological and institutional management strategies. The Bay of Bengal has been increasingly important for local development as well as for a global perspective. The coastal and marine fisheries of the Bay of Bengal are briefly reviewed in this paper to provide a salient feature of the available information and resource base and to identify future research and management needs.