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671.
ABSTRACT: The effects of a moving rainstorm on flood runoff characteristics were investigated. A flood hydrograph simulation model called “FH-Model” and a natural watershed were used. A hypothetical rainstorm of 50 years recurrence interval, 75 mm depth, and 4 hours duration was used to show the effects of velocity and direction of the moving rainstorm on the runoff characteristics. Compared with an equivalent stationary rainstorm (ESRS), the peak flow caused by a rainstorm moving in a downstream direction with a speed equal to channel velocity, V, was 27.5 percent higher and the peak flow caused by the same rainstorm moving in an upstream direction was 21.7 percent smaller. These percentages reduced to 10.5 percent and 8.6 percent for storms moving downstream and upstream, respectively, at three times the channel velocity, 3V. There were negligible differences in the time of peak, Tp between runoff caused by storms moving downstream and runoff produced by ESRS. However, Tp for a storm moving upstream at V velocity was 82 percent higher than that produced by ESRS, but was reduced to 27 percent higher when the storm velocity was 3V.  相似文献   
672.
Legislation settling the Alaska Native Lands Claims also resulted in the establishment of ten new parks and preserves in Alaska. This settlement was the result of a long and often bitter legislative struggle between pro- and antidevelopment groups. The planning history of the Wrangell-St. Elias National Park and Preserve is used as a case example of this debate. One particular source of conflict was the curtailment of sport hunting that would result under national park classification. A preserve classification was introduced to resolve this conflict. Data on wildlife resources and sport hunting were instrumental in defining the areas so classified.  相似文献   
673.
An economic analysis of nonpoint source pollution management was conducted for the Nansemond River and Chuckatuck Creek watersheds in Southeast Virginia. The potential effects of alternative public policies on farm income, land use, and pollution loadings were investigated. Regulatory programs could have quite different impacts depending on which pollutant is targeted. Cost-share rates greater than 50 percent would have little additional effect on pollution from crop enterprises, but would reduce pollution from livestock  相似文献   
674.
675.
The demand for more water is increasing throughout the country. Research on upland watersheds clearly demonstrates that water yield can be increased using forest and range management practices. Based on the experience of the past several decades and a review of six papers in a recent AWRA series on water yield augmentation through vegetation management, the following issues and concerns are discussed: predicting increased yields from large basins; economic evaluation of additional flows; court acceptance and need for system models; the legal question of ownership and transferability of increased yields; and management emphasis on private and federal lands. The immediate potential for water yield augmentation is on carefully selected watersheds that have the bio-physical potential to produce high value water under environmentally acceptable multiple use management. We predict water yield management on a broader scale will result from increased pressures to solve the legal and economic issues involved.  相似文献   
676.
ABSTRACT: Tradeoffs between regional economic development and resource use is a question often confronting local decisionmakers. A resource-interindustry model can be used to depict the interrelationships between regional economic sectors as to household income and/or employment and resource use. A resource-interindustry model was developed for Humboldt and Lander Counties in Nevada which shows the tradeoffs between regional household income (wages, salaries, profits, and rents) and/or employment and water usage. Water income and water employment multipliers can be ranked, enabling decisionmakers to realize sectors which require greatest regional water usage to regional household income and/or employment.  相似文献   
677.
Management of river basins involves the making of informed choices about the desired levels of economic activities and ecosystem functioning in the catchment. Information on the economic and ecological effects of measures as well as their spatial distribution is therefore needed. This paper proposes the following instruments to support decision-making in river basins: (1) the linking of models and indicators to describe the economic and ecological effects of management actions and their spatial distribution and (2) an extended evaluation framework that aims to evaluate management actions on three objectives for sustainable river management. These are cost-effectiveness, spatial equity, and environmental quality. This paper illustrates the potential of these instruments for river basin management by a case-study on nutrient management in the Rhine basin. In this case-study four nutrient abatement strategies are formulated, based on policies of the International Commission for the Protection of the Rhine and the North Sea Commission. These strategies are analysed and evaluated on their contribution to the three management objectives. Results show that none of these strategies score highest on cost-effectiveness, spatial equity and environmental quality simultaneously. It appears that cost-effectiveness is in conflict with environmental quality, whereas spatial equity and cost-effectiveness show quite close correspondence. This means that a trade-off has to be made between costs and spatial equity on the one hand, and environmental standards on the other hand. This paper offers a framework to make these trade-offs more explicit and provides quantitative information on cause-effect relationships, economic and environmental effects and the spatial distribution of these effects for various management strategies. This information can be particularly useful in the development of compromises required to establish international agreement and co-operation.  相似文献   
678.
Niobium, phosphate, coal and gold mining facilities have been selected as case studies with the aim of identifying possible sources of radiological impact during and after cessation of industrial operations. The results have shown that acid drainage, as well as chemical processing of mineral ores, constitute relevant impact indicators for present-day and future scenarios. The possible use of solid wastes abandoned at the end of the operations represents a long-term radiological concern. Therefore, it is necessary that Brazilian legislation for environmental licensing be revised taking into account the potential environmental and radiological impacts caused by these industries and establishing remedial procedures for waste storage areas in the existing sites. The indicators developed and procedures carried out can be used in screening for decisions on the adoption of regulatory requirements for practices at such types of installations.  相似文献   
679.
Many of Canada's ex-urban and rural areas face a daunting array of sustainability challenges. In developing effective sustainability strategies, these areas must rely heavily upon local resources and capacities and existing social capital. Part of the solution for these areas may lie in multi-stakeholder collaborative approaches built on sustainability principles and strategies. These include the engagement and mobilization of civil society networks; the cultivation of strategic partnerships among key stakeholders in civil society, the private sector and government; and long-term local programmes of research, education and advocacy that are supportive of sustainability. This article describes and analyses a Canadian case study—Dufferin County, part of the Headwaters Country region in southern Ontario—in which a multi-stakeholder, civil society based approach to fostering sustainability is currently unfolding. The ideological and theoretical underpinnings of the initiative are explored, key process-oriented and substantive challenges to the approach are analysed and action research strategies are discussed.  相似文献   
680.
ABSTRACT: Devils Hole is a collapse depression connected to the regional carbonate aquifer of the Death Valley ground water flow system. Devils Hole pool is home to an endangered pupfish that was threatened when irrigation pumping in nearby Ash Meadows lowered the pool stage in the 1960s. Pumping at Ash Meadows ultimately ceased, and the stage recovered until 1988, when it began to decline, a trend that continued until at least 2004. Regional ground water pumping and changes in recharge are considered the principal potential stresses causing long term stage changes. A regression was found between pumpage and Devils Hole water levels. Though precipitation in distant mountain ranges is the source of recharge to the flow system, the stage of Devils Hole shows small change in stage from 1937 to 1963, a period during which ground water withdrawals were small and the major stress on stage would have been recharge. Multiple regression analyses, made by including the cumulative departure from normal precipitation with pumpage as independent variables, did not improve the regression. Drawdown at Devils Hole was calculated by the Theis Equation for nearby pumping centers to incorporate time delay and drawdown attenuation. The Theis drawdowns were used as surrogates for pumpage in multiple regression analyses. The model coefficient for the regression, R2= 0.982, indicated that changes in Devils Hole were largely due to effects of pumping at Ash Meadows, Amargosa Desert, and Army 1.  相似文献   
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