丽水市大气环境中的城市干、湿岛效应初探

利用丽水城区中心及其近郊2个站点的逐时水汽压资料,定义了干(湿)岛强度指数及干(湿)岛强度等级,并发现了丽水小城区干(湿)岛变化强度、频次及时空分布规律,研究发现城区中心的干岛现象与热岛现象之间存在着正相关.湿岛的形成与露、雾、结冰、霜、雨等天气现象有关.     

Marsh surface sediment deposition and the role of tidal creeks: Implications for created and managed coastal marshes

The need to understand the processes contributing to marsh sedimentation has become more urgent with the recent recognition of the role of tidal marshes as sea defences, as well as the many restoration efforts currently under way. This study was designed to build upon previous sedimentation work at Scolt Head Island by Combining techniques for measuring short-term sedimentation, with detailed assessment of hydroperiod, previously used only in comparison with longer-term accretion measurements or in micro-tidal systems. Measurements of water level, sediment deposition (at various distances from the creek margin) and suspended sediment concentration (SSC) (creek margin and an interior site) were made at Hut Marsh over three sequential over-marsh tides during May 1994. Sediment trap data show a significant trend of declining sediment deposition away from the creek when data from all three tides are combined. All tides show higher SSC on the flood tide than on the ebb tide at the creek margin location. There is little difference in flood and ebb SSCs at the interior site. An order of magnitude decrease in sediment deposition within 20 m on the creek shows the rapidity with which sediment is deposited on these marshes. Higher tides influence both the magnitude and pattern of marsh surface sediment deposition. Increased creek velocities on higher tides provide more potential for resuspension within the creek and increase the supply of sediment to the marsh surface. This study suggests that the design of tidal creeks may be essential for the development of sustainable coastal marshes in restoration projects.     

Water resources issues of small island developing states

The water resources of most small island developing states (SIDS) are often very limited and require special consideration to ensure that they are developed and managed in a sustainable manner. Many small islands, typically located in the humid tropics, have no surface water resources and rely on limited groundwater resources in the form of thin freshwater lenses. The exposed location of small islands makes them particularly vulnerable to natural disasters such as cyclones, floods and droughts. Pollution from population centres and from agricultural and other activities is an increasing problem. This article provides an overview of the water resources of small islands, and the main problems and issues related to water resources. Some suggested solutions, based on practical experiences, are offered for water resource assessment and monitoring programmes, and water resource development. Water resource policy, planning and management issues are also addressed, and suggested approaches for resolving some of the major water resource problems presented.     

Small island developing states and sustainable development of ocean resources

Because of their economic and environmental vulnerability, small island developing states (SIDS) have peculiar developmental problems that severely affect their ability to implement the measures necessary for attaining sustainable development as recommended in UNCED's Agenda 21. Although this has been recognised by the Commission on Sustainable Development (CSD), and although there has been international acceptance of a SIDS Programme of Action (POA), SIDS have not been the focus of adequate attention by international and donor agencies. As a result, progress toward implementing the POA has been disappointing. This study examines the question of how sustainable management and development of ocean resources can contribute significantly to the achievement of the objectives of the SIDS POA.     

渤海和濑户内海环境立法的比较研究

对我国渤海和日本濑户内海的环境问题进行了阐述,并介绍了相关立法的背景。对中日两国适用渤海和濑户内海的国际法律制度、国内法律文件、环境保护的其他重要文件,如规划计划等进行了研究,并在此基础上对渤海和濑户内海环境立法的比较分析。得出了为恢复和保护渤海的整体功能,促使渤海为社会经济发展提供持续的支持,必须借鉴日本治理濑户内海的经验,建立渤海这一内海的特别法规体系和资源环境可持续利用的管理制度,并形成一系列与之对应的政策,只有这样,才能从根本上保障渤海整治的综合效果和渤海的可持续利用能力的结论。     

唐山月坨列岛自然保护区的开发与保护

根据唐山月坨列岛自然保护区的特点和存在的生态环境问题,提出了保护措施。     

崇明岛开发的自然秉赋与制约

在2l世纪世界环境与发展相互协调的历史背景下，有着自然优势的崇明岛开发成为上海现代化发展第三次飞跃的战略性目标之一。从长江口和崇明岛发育自然和人工控制后自然适应演变规律的历史和现状，探讨实现崇明岛开发的自然秉赋与制约因素，近两千年来长江河口自然演变规律的分析结果表明：弯道侧向环流及其对泥沙的输运对河口沙坝和汉道发育演变以及流域内众多大型工程对河口环流结构的影响研究，将是对长江口综合治理的理论前提，更是崇明岛实现人与自然协调开发的基础。而且，风能、湿地生态功能和岛内沟河网的自然生态功能、湿地生态功能和岛内沟河网的自然生态功能等可再生资源的充分利用可以实现崇明岛的零污染开发和治理。     

Snowblower injuries in Vermont, 1981–1984

The Vermont Department of Health carried out two studies of snowblower injuries in Vermont during the winters of 1982–1983 and 1983–1984. The first was a case-control study in which we assessed risk factors that predisposed operators to injury during snowblower use. We found 20 persons who had been injured by snowblowers and matched 28 controls to these by neighborhood. In this study, owning a snowblower for 1 year or less and having operated a snowblower for 10 days or less in one's lifetime were significantly associated with injury. The second study was population-based. We estimated that approximately 1.5% of Vermont residents owned snowblowers during the winter of 1982–1983 and that, among snowblower owners, injuries occurred at a rate of 1.3/1,000 person-years of ownership (0.1% chance of injury).     

Risk cognition and the public: The case of Three Mile Island

Residents of within 50 miles of the nuclear power plant at Three Mile Island (TMI), Pennsylvania, were surveyed in 1979, 1980, and 1982 to assess their general attitudes toward nuclear power, to assess their individual coping responses to the March 1979 accident, and to monitor changes in attitudes over the three-year period. Most respondents feel that future accidents like TMI will occur once or twice more in their lifetimes, that operating nuclear power stations should have improved safeguards and should continue operating, and that major institutions—government and utility companies—are experiencing a continued erosion of public trust.     

Freshwater Wetland dynamics in South Kingstown,Rhode Island, 1939–1972

The extent and causes of changes in the fresh-water wetlands of South Kingstown, Rhode Island were determined through field work and through the analysis of panchromatic aerial photographs taken in 1939 and 1972. During this period, there was a net loss of 0.9 percent of the total area (2345.2 ha) of wetland present in 1939. Highway construction and residential development accounted for most of this loss. Approximately 17 percent of the wetland present in 1939 had changed sufficiently by 1972 to warrant reclassification. Plant succession alone accounted for 57 percent of the changes in wetland types, while man's activities were influential in 41 percent of the cases. Ninety-two percent of the natural changes in wetland types was progressive, while 58 percent of the changes induced by man and undetermined causes was retrogressive. Man's major role was to alter the water regimes and vegetation of wetlands. There was a decrease in wetland diversity as the most abundant type, wooded swamp, grew in area while the abundance of shallow marshes, meadows, and shrub swamps declined. A knowledge of wetland dynamics is essential in the management of wetlands for a diversity of wildlife and other natural values.