坝对环境影响的经济分析方法

修建大坝是社会性的大投资,其主要用途是供给生活及工业用水、能源生产、灌溉及防洪,除了这些直接效益外。坝及其水库储水还将产生一些相关的环境影响.本文简述了坝工程对水库流域的各种环境影响,着重阐述了用货币估价环境影响的经济分析方法。      

The wilderness use simulation model applied to Colorado River boating in Grand Canyon National Park,USA

A modification of the Shechter-Lucas Wilderness Use Simulation Model (WUSM) for peak season boating on the Colorado River through Grand Canyon National Park, USA, is evaluated as a tool for making management decisions. A new microcomputer program to select trip itineraries for inclusion in the WUSM that was developed as part of this study is presented. This program simplifies user input and expands the WUSM's usefulness as a tool for management decisions by randomizing itinerary schedules based on probabilities developed from actual use of sites by canyon visitors. Model usefulness is demonstrated by simulating various management changes and comparing use levels of attraction sites and campgrounds as well as numbers of encounters between parties. The WUSM is being used as part of an ongoing study, to reflect the impact of fluctuating flow regimes through the turbines at Glen Canyon Dam on river trips.     

Snow avalanche hazards in the Glen Nevis and Glen Coe areas of Scotland

Until quite recently, snow avalanches in Britain had caused only a few deaths and the occasional destruction of property. Since about 1950, however, the number of people involved in avalanche accidents has risen sharply, particularly in Scotland. The main reason for this has been the growing popularity of mountaineering. This paper examines the situation in the Glen Nevis and Glen Coe areas of the Western Highlands. The types of avalanche occurring at these localities are briefly discussed and relationships between avalanche characteristics and accidents are examined. Mountaineers are the group chiefly responsible for the increase of avalanche deaths and injuries in the Glen Nevis and Glen Coe areas. Responses to the hazard are considered and these are shown to be inadequate. As elsewhere in Scotland, much more research is needed if a further worsening of the problem is to be avoided.     

岗南水库大坝安全稳定分析

为了保证岗南水库大坝的安全运营 ,采用Fellenius圆弧法对整个岗南水库大坝断面的安全稳定性进行了分析 ,确定了不满足稳定性要求的断面的最小稳定安全系数及其最危险滑弧位置 ,并对其可能的原因进行了分析评价 ,给出了结论和建议     

Socioeconomic and Institutional Dimensions of Dam Removals: The Wisconsin Experience

/ There are tens of thousands of small dams in the United States; many of these aging structures are deteriorating. Governments and dam owners face decisions regarding repair or removal of these structures. Along with the many benefits society derives from dams and their impoundments, numerous recent ecological studies are revealing the extensive alteration and degradation of river ecosystems by dams. Dam removal-a principal restoration strategy-is an infrequent event. The major reasons for removal have been public safety and the high costs associated with repair; the goal of river ecosystem restoration now warrants greater attention. Substantial study is being given to the environmental aspects of dams and dam removals, but very little attention has been given to the socioeconomic and institutional dimensions associated with the removal of dams, although these factors play a significant role in the removal decision-making process. Based on a case study of dam removals in Wisconsin-where more than 30 of the state's 3600 small dams have been removed in the past few decades-legal, financial, and socioeconomic issues associated with dam removal are documented and assessed. Dam removal has been complex and contentious, with limited community-based support for removal and loss of the impounded waters. In cases examined here, the estimated costs of repairing a dam averaged more than three times the cost of removal. The availability of governmental financing has been a key determinant in removal decisions. Watershed-scale ecological considerations are not major factors for most local interests. As watershed management and restoration increasingly include dam removal options as part of an integrated strategy, more attention will need to be focused on socioeconomic factors and stakeholder perspectives-variables that strongly influence the viability of this management alternative.KEY WORDS: Dam removal; River restoration; Institutions; Stakeholders     

水布垭大坝坝址左岸岩溶化地层三维计算机模拟

详尽地阐述了由多个椭球洞体生成复杂溶蚀孔洞的原理、三维随机洞体的数学模型以及确定性洞体的数学描述和计算机显示方法,为岩溶化岩体的溶蚀率和渗透特性的研究提供了计算机模拟手段。根据野外现场调查资料、平面地质图、灌浆帷幕剖面图,提取了水布垭大坝坝址左岸岩溶化地层的有关数据,得到了岩溶化地层的三维地质图和沿灌浆帷幕线的剖面图。     

北江大堤洪水风险图信息管理系统中仿真模型的开发研究

“北江大堤洪水风险信息管理系统”中洪水仿真模型的研究, 是根据北江大堤可能出现的溃堤风险,模拟了北江大堤溃决后保护区内洪水的演进过程,模型的计算结果提供的淹没水深、淹没范围、淹没历时以及流速等洪水风险信息, 为北江大堤洪水风险图的绘制提供了依据     

Regional economic impacts of Grand Canyon river runners

Economic impact analysis (EIA) of outdoor recreation can provide critical social information concerning the utilization of natural resources. Outdoor recreation and other non-consumptive uses of resources are viewed as environmentally friendly alternatives to extractive-type industries. While outdoor recreation can be an appropriate use of resources, it generates both beneficial and adverse socioeconomic impacts on rural communities. The authors used EIA to assess the regional economic impacts of rafting in Grand Canyon National Park. The Grand Canyon region of northern Arizona represents a rural US economy that is highly dependent upon tourism and recreational expenditures. The purpose of this research is twofold. The first is to ascertain the previously unknown regional economic impacts of Grand Canyon river runners. The second purpose is to examine attributes of these economic impacts in terms of regional multipliers, leakage, and types of employment created. Most of the literature on economic impacts of outdoor recreation has focused strictly on the positive economic impacts, failing to illuminate the coinciding adverse and constraining economic impacts. Examining the attributes of economic impacts can highlight deficiencies and constraints that limit the economic benefits of recreation and tourism. Regional expenditure information was obtained by surveying non-commercial boaters and commercial outfitters. The authors used IMPLAN input-output modeling to assess direct, indirect, and induced effects of Grand Canyon river runners. Multipliers were calculated for output, employment, and income. Over 22,000 people rafted on the Colorado River through Grand Canyon National Park in 2001, resulting in an estimated $21,100,000 of regional expenditures to the greater Grand Canyon economy. However, over 50% of all rafting-related expenditures were not captured by the regional economy and many of the jobs created by the rafting industry are lower-wage and seasonal. Policy recommendations are given for increasing the regional retention of rafting expenditures and for understanding both the beneficial and adverse impacts that accompany outdoor recreation in rural areas.     

Brazil's Balbina Dam: Environment versus the legacy of the Pharaohs in Amazonia

The Balbina Dam in Brazil's state of Amazonas floods 2360 km² of tropical forest to generate an average of only 112.2 MW of electricity. The flat topography and small size of the drainage basin make output small. Vegetation has been left to decompose in the reservoir, resulting in acidic, anoxic water that will corrode the turbines. The shallow reservoir contains 1500 islands and innumerable stagnant bays where the water's residence time will be even longer than the average time of over one year. Balbina was built to supply electricity to Manaus, a city that has grown so much while the dam was under construction that other alternatives are already needed. Government subsidies explain the explosive growth, including Brazil's unified tariff for electricity. Alternative power sources for Manaus include transmission from more distant dams or from recently discovered oil and natural gas deposits. Among Balbina's impacts are loss of potential use of the forest and displacement of about one third of the surviving members of a much-persecuted Amerindian tribe: the Waimiri-Atroari. The dam was closed on 1 October 1987 and the first of five generators began operation in February 1989. The example of Balbina points to important ways that the decision-making process could be improved in Brazil and in the international funding agencies that have directly and indirectly contributed to the project. Environmental impact analyses must be completed prior to decisions on overall project implementation and must be free of influence from project proponents. The current environmental impact assessment system in Brazil, as in many other countries, has an undesirable influence on science policy, in addition to failing to address the underlying causes of environmentally destructive development processes and inability to halt irreversible projects like Balbina.