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161.
滨海沙土是广东沿海重要而急待改造利用的一种国土资源。分布广、面积大,风沙为害较甚。它集中分布在琼东北和西南部、陆丰至海丰、阳江至广州湾沿岸一带。主要因河流和地表径流携带的泥沙受潮浪、风力作用逐渐发育而成。按形成时间和特性,可分流动、半固定、固定和耕型沙土等亚类。并具有沙瘦的共同特性。改造利用主要措施是营林绿化。其次,是因地制宜地积极发展果蔬、热作等经济作物,改造沙荒草地,发展畜牧业,施肥改土,兴修水利和开发其旅游资源。  相似文献   
162.
沿海港口水域污染及其治理对策   总被引:2,自引:0,他引:2  
介绍了我国港口的水域污染现状,指出港湾水域和近海污染已成为我国海洋污染的重点。分别阐述了港口水域的主要污染和污染物:疏浚物,化学品,生活污水,货物粉尘,垃圾及重金属等的来源及其危害。同时,提出改善港口环境管理和提高港口水域污染防污技术的方法和措施。  相似文献   
163.
The case is made in this paper for early and integrative public participation in planning decisions concerning proposals major development in the zone. This is perhaps easy to subscribe to in theory but much more difficult in practice. Currently the extent and timing of public involvement in such decisions varies widely. A key benefit is the legitimacy that public participation provides to the planning process and, perhaps as a result, a variety of public involvement methodologies have emerged. Important considerations include which sections of the public to involve and at what stage in the decision-making process to involve them. The multidisciplinary nature of coastla zone issues will tend to engage a wide variety of stakeholder groups who in turn will influence the topics for discussion. A major port expansion proposal in the UK is used to illustrate a range of ways in which the public can be involved. The case study also highlights that public participation is an uncertain science, and to be successful can require skilled personnel and significant resources. The papper concludes that more guidance for developers, some standardisation of public involvement, training for facilitatiors and a more responsible stance from some environmental pressure groups would be advantageous. The complexity of coastal decision-making, tensions between science and policy, and the inter-dependency of coastal activities mutually reinforce the view that inclusive participation is an important issue for all coastal communities.  相似文献   
164.
Many coastal regions in China are confronted with pressing problems of scarce land resources and heavy population. Over the past 30 years, considerable parts of coastal tidelands have been enclosed and reclaimed for agricultural land uses. To assess, plan, and implement large-scale reclamation programs, up-to-date and reliable information concerning the nature, areal extent, and physical and chemical characteristics of coastal saline lands is essential. This paper reports a remote sensing approach to detecting coastal saline land uses in Shangyu City, China, by using multi-temporal Landsat images. First, with the aid of resolution-sharpened Landsat-7 ETM+ images and their enhanced linear features, a visual interpretation is applied to extract individual dikes. Based on time series images and local government records, a spatial zoning procedure is then used to define six sub-zones with different historical years of reclamation. It shows that a total of 15,668 ha of coastal saline lands were enclosed and reclaimed from 1969 to 1996. Second, a modified land-use classification system for the study area is prescribed, and both unsupervised and supervised classifiers are performed for land-use classifications of grouped sub-zones. Information obtained from the spatial zoning, Tasseled Cap transformation and Normalized Difference Vegetation Index, is also utilized to facilitate the supervised classification process. Finally, a detailed land-use map is produced, with an overall classification accuracy of 77.8%. Results show that dominant agricultural land uses of sub-zones are changed with historical reclamation years, from saline lands with wildgrass (very recently reclaimed) to aqua-farm ponds, to cotton fields, and to paddy fields and orchards (very early reclaimed). This transform process is primarily affected by soil salinities, and according to a soil survey an electrical conductivity of saturation extract decreased from 7.3 ds/m in the saline land reclaimed in 1996 to below 2 ds/m in the land reclaimed before 1969. The study concludes that multi-temporal remotely sensed images are important and effective data sources for monitoring the rapid changes of coastal land uses.  相似文献   
165.
Carbon dioxide (CO2) emissions from aquatic ecosystems are important components of the global carbon cycle, yet the CO2 emissions from coastal reservoirs, especially in developing countries where urbanization and rapid land use change occur, are still poorly understood. In this study, the spatiotemporal variations in CO2 concentrations and fluxes were investigated in Wenwusha Reservoir located in the southeast coast of China. Overall, the mean CO2 concentration and flux across the whole reservoir were 41.85 ± 2.03 µmol/L and 2.87 ± 0.29 mmol/m2/h, respectively, and the reservoir was a consistent net CO2 source over the entire year. The land use types and urbanization levels in the reservoir catchment significantly affected the input of exogenous carbon to water. The mean CO2 flux was much higher from waters adjacent to the urban land (5.05 ± 0.87 mmol/m2/hr) than other land use types. Sites with larger input of exogenous substance via sewage discharge and upstream runoff were often the hotspots of CO2 emission in the reservoir. Our results suggested that urbanization process, agricultural activities, and large input of exogenous carbon could result in large spatial heterogeneity of CO2 emissions and alter the CO2 biogeochemical cycling in coastal reservoirs. Further studies should characterize the diurnal variations, microbial mechanisms, and impact of meteorological conditions on reservoir CO2 emissions to expand our understanding of the carbon cycle in aquatic ecosystems.  相似文献   
166.
• Reclamation projects are important disturbances on microplastic risk in coasts. • Tidal-flat reclamation area is a large storage medium for sedimentary microplastics. • Aging and distribution features of soil microplastics show spatial heterogeneity. • Coastal weathered engineering geotextiles are a significant threat to marine health. Coastal tidal flats have received considerable attention in recent years, as they provide a direct channel for the discharge of terrestrial microplastics into the ocean. Land reclamation is occurring increasingly frequently in coastal tidal-flats; however, the environmental impacts of these activities remain unclear. Therefore, this pioneering study assessed the microplastic emission characteristics of reclamation geotextiles and performed a risk assessment accordingly. Morphological characterization of geotextile samples collected from five sites in Dongtai, China, provided evidence of sedimentary weathering. Based on several assumptions, the average abundance of microplastics in soil covered by geotextiles was estimated to reach 349±137 particles/kg dry weight, with the total microplastic load in the reclaimed area estimated to be 20.67±8.06 t. Compared with previous studies, this research demonstrates that coastal reclamation areas store a high concentration of microplastics, aggravating marine microplastic pollution. Moreover, conditional fragmentation model results revealed that the weathering and distribution characteristics of soil microplastics in coastal tidal-flat areas exhibit spatial heterogeneity, being more easily affected by natural factors (such as tides) than those in inland areas. As a result of tides, the annual discharge of geotextile-originating microplastics from the studied areas into the ocean was approximately 2465.52±960.77 t. These findings prove that the risks posed by engineering-microplastics are significant, indicating that further investigations are required on the precise laws of transfer and migration, as well as the toxicity mechanisms, in order to improve analytical techniques and policies in this field.  相似文献   
167.
Climatologists generally expect an anthropogenic global warming that could raise sea level 30–150 cm in the next century and more thereafter. One of the impacts would be the loss of coastal wetlands. Although the inundation of adjacent dryland would enable new wetlands to form, much of this land is or will soon be developed. If developed areas are protected, wetlands will be squeezed between an advancing sea and the land being protected, which has already happened in China and the Netherlands, where people have built dikes for centuries. Unlike those countries, the United States has enough land to accommodate the landward migration of wetlands; but governments lack the funds to purchase all the coastal lowlands that might be inundated and the legal authority to prohibit their development. We propose a third approach: allowing property owners to use coastal lowlands today as they choose, but setting up a legal mechanism to ensure that the land is abandoned if and when sea level rises enough to inundate it. Although compensation may be required, this approach would cost less than 1% as much as purchasing the land, and would be (1) economically efficient by enabling real estate markets to incorporate expectations of future sea level rise; (2) constitutional by compensating property owners; and (3) politically feasible by pleasing people who care about the long-term fate of the coastal environment without disturbing people who either are unconcerned about the distant future or do not believe sea level will rise. This article demonstrates that it would be irrational to delay policy formulation until sea level rise projections are more precise. The cost will be small if we act now but great if we wait, and sea level is already rising along most coasts. The US government should develop a strategy in the next three years. The opinions expressed in this paper do not necessarily reflect the views of EPA and no official endorsement should be inferred.  相似文献   
168.
Integrated Coastal Zone Management as a strategy for achieving conservation and sustainable multiple use of the coastal zone includes various types of management initiatives. Due to natural phenomena such as tides and winds and to social and economic activities, coastal areas undergo transformation. Coastal erosion and the disappearance of beaches as a result of wrong planning decisions and lack of effective legislation are among the most damaging effects and to reverse them requires application of a series of engineering techniques. Beach nourishment projects as a way towards shore protection and utilization through recreational purposes in the Spanish and Italian coasts are noteworthy in this respect. In beach nourishment projects, the roles of various entities, both public and private, should be clearly indicated and in the evaluation and execution stage a series of questions should be answered for the successful completion of any nourishment project. Past projects in the Mediterranean and experiences from recent Italian projects in Anzio and Nettuno confirm this. For example, dredging of the entrance channel of the port of Anzio enabled middle-sized ferryboats once again to enter the port (which had not been possible before). This will in turn increase the tourism potential of the town. Nourishment of two beaches at these sites prevented further erosion and provided more area for recreational purposes. Expected economic contribution of beach nourishments to the regional authority was estimated for Nettuno and Anzio; the resulting theoretical payback period was found to be 3 yr for the former and 15 yr for the latter.  相似文献   
169.
This paper concludes the publication of theJournal of Coastal Conservation from 1995–2004 after the European Coastal Union and the Publishers decided to terminate the production of the journal. We look back at the 206 research papers published in this period while concentrating on Geographical and ecological variation, Focuses and trends, and Progress in European coastal conservation and management. Three indices are added: (1) a list of the 206 papers; (2) an Author Index; and (3) a Subject Index based on the titles, keywords and some additional important subjects found in the tables and figures.  相似文献   
170.
Fifteen beaches from the Swansea Bay coastal sediment cell, South Wales, UK, were analysed via function analysis, involving assessment of specific environmental and socio-economic indicators. These were allocated scores from field surveys and extensive desktop studies, which included beach awards, relevant shoreline management plans, planning and conservation designations and current legislation. Normalised scores allowed production of a conservation/development matrix, enabling beach location in conservation, development or conflict fields, which results appropriately identified. Conservation field beaches tended to have a low density residential hinterland with little or no commercialisation. Conversely, beaches that leant towards the development field had a high density residential hinterland and were highly commercialised. Evaluation showed the importance of planning legislation in conflict areas and identified locations of development potential, where significant environmental consequences would be unlikely. This representation could be used for evolution of conservation/development status within coastal areas, enabling policy adjustment as necessary. It will also enable future sustainability assessment and it is suggested that indicators could be modified to reduce environmental emphasis and provide a more uniform socio-economic consideration.  相似文献   
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