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1.
The apparent effect of selected reservoir environmental variables-including surface area, mean depth, outlet depth, thermocline depth, water level fluctuation, storage ratio, shore development, total dissolved solids, growing season and age of reservoir–on fish standing crop in 140 large impoundments has been explored through partial correlation and multiple regression analyses. The sample was partitioned into 25 subsamples based on reservoir use type, water exchange rate, thermocline formation and water chemistry. Fish standing crops were estimated by summer rotenone sampling of coves or open water areas enclosed by blockoff net. Logarithmic partial correlation revealed highly significant (0.01 confidence shore development and dissolved solids on At the 0.20 confidence level, the crop of storage ratio and shore level) positive effects of outlet depth, total standing crop in the entire sample. all sport fishes is positively influenced by outlet depth, development and negatively by mean depth. In 54 hydropower reservoirs with a stable thermocline, positive effects of increased storage ratio and dissolved solids on t o t a l crop are evident at the 0.05 confidence interva. Increase in thermocline depth has a negative effect. In 25 hydropower reservoirs without a stable thermocline, clupeid (shad) crop is negatively correlated with surface area, mean depth and fluctuation. Reservoirs with a thermocline have higher standing crops than those without. At the species or species group level, partial correlation of nine environmental variables a t the 0.05 confidence interval reveals: Positive effect of surface area on pike and pickerel; buffalo-fishes, white crappie and total sport fish crop; positive effect of outlet depth on largemouth bass, catfishes, total sport fish crop and buffalofishes; a negative effect of water level fluctuation on pike and pickerel, redear sunfish and gizzard shad; a positive relationship between storage ratio and channel catfish and bull- heads and a negative one with flathead catfish and suckers; a positive effect of total dissolved solids on black and whit basses, catfishes, gizzard shad, carpsuckers and carp. A morphoedaphic expression, total dissolved solids divided by mean depth, provides a useful index t o reservoir fish production. The relationship is curvilinear, with maximum crops expected at index values of 5 t o 30.The index accounts for 62 percent of the variability in hydropower storage reservoir crops. Several multivariable regressions have been derived f o r predictive purposes. Examples are included, with R values of 35 t o 60.  相似文献   

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ABSTRACT. Over the last few years, several studies sponsored by both government and interested national engineering associations have evaluated the relative merits of pressure sewer systems. Surprisingly little data has been forthcoming, however, with regard to the effects of pressure sewers on both the economics of land development and the country's water resources. The intention of our paper is to detail the salutary effects of pressure sewers on water supply resources, the indirect effect on other resources by decreasing the contribution of sanitary sewage to their pollution, and to illustrate where, in some locations of the country, pressure sewers would benefit the economics of land development. As engineers from a large industrial firm that has built hardware that will allow the concepts stated above to become realities, we will present data to enforce our convictions. Some effects on municipal treatment plants, and emplacement costs of the system are described. Since the main thrust of our paper is to treat the effect of pressure sanitary sewers on the water resources of the country, specific peripheral data is not presented at length. The pressure sewer effects on lowering water usage in homes and the decrease in groundwater contamination by replacing septic tanks with pressure sewers in selected locations is presented. Advanced technology concepts such as energy assisted sewer systems should be considered as a favorable economic manner in which to preserve selected water resources. During the 1965 drought that affected the Northeastern section of the U.S., a federal government document reported that there was really no shortage of water, but that present water resources lacked management. Pressure sewers may be a water resources management tool and an effective one if not promulgated as a cure-all for the water pollution problems facing this nation.  相似文献   

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ABSTRACT: Alternative approaches suggested for modeling multiseries of water resources systems are reviewed and compared. Most approaches fall within the general framework of multivariate ARMA models. Formal modeling procedures suggest a three-stage iterative process, namely: model identification, parameter estimation and diagnostic checks. Although a number of statistical tools are already available to follow such modeling process, in general, it is not an easy task, especially if high order vector ARMA models are used. However, simpler ARMA models such as the contemporaneous and the transfer-function models may be sufficient for most applications in water resources. Two examples of modeling bivariate and trivariate streamflow series are included. Alternative modeling procedures are used and compared by using data generation techniques. The results obtained suggest that low order models, as well as contemporaneous ARMA models, reproduce quite well the main statistical characteristics of the time series analyzed. It is assumed that the same conclusions apply for most water resources time series.  相似文献   

4.
The international community has a stake in reducing certain avoidable risks of mineral development in developing countries and in promoting more advantageous relations between these countries and transnational mining companies. In the following article, the author examines various programmes of the United Nations Centre on Transnational Corporations which contribute to the achievement of these objectives.  相似文献   

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The Committee on Natural Resources, which meets every two years, is the primary intergovernmental body of the United Nations dealing with natural resources matters. In the following article, the author summarizes briefly some of the issues before the Committee at its most recent session, which convened in Geneva in May 1977, and the recommendations adopted by participating governments.  相似文献   

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Borehole geophysics comprises the execution of physical measurements in boreholes and the interpretation of the results in terms of rock properties and other data useful in subsurface investigations. This article briefly reviews the borehole geophysical methods that have found acceptance in hydrology and their main applications.  相似文献   

9.
ABSTRACT: Texas is one of the states in which limitations in water supplies could severely constrain economic growth in certain areas. The traditional planning approach for addressing this problem has involved devising schemes for large water development projects, which for many years included the importation of water from other states. Now the attitude towards water resource management is changing, and it is generally agreed that better management of existing supplies is the preferred approach. In this paper we review some of the changes that have recently occurred in Texas, including attempts to streamline the water institutions in such a way that they might be more responsive to the need for more comprehensive management of water resources statewide, with greater emphasis on social and environmental concerns.  相似文献   

10.
ABSTRACT: Methods of floodplain management are changing in the United States. There has been a gradual shift in emphasis from “flood control” to “management” of the floodplain. The complexities of multilevel governmental involvement in floodplain management demand an analysis of a new means to coordinate these efforts. It is the intent of this paper to discuss the role of the Corps of Engineers in this area and the problems the Corps has encountered in its endeavors. The occurrence of these problems indicates that there is a need to strengthen the federal role to ensure a comprehensive view of floodplain management.  相似文献   

11.
ABSTRACT: Federal spending on water resource development projects exceeds $10 billion annually. This paper examines the economic theory and practice on which the Federal water resource development plans are based. Existing theoretical and applied problems result in overinvestment. These include 1) no standard of value for the tradeoff of environmental objectives with economic objectives; 2) benefits based on “willingness to pay,” but beneficiaries pay only a fraction of a project's costs; 3) beneficiaries “shop around” among program purposes in order to reduce their commitments; and 4) benefit/cost (B/C) analyses are based on a discount rate, which is consistently below the Federal borrowing rate. Furthermore, the Government Accounting Office (GAO) frequently finds that the agency regulations are inadequate and result in inconsistent and questionable benefit computations. The President has proposed a series of water policy reforms, to reduce some of the apparent overinvestment in water resource development, but fundmental corrective action rests with the members of Congress.  相似文献   

12.
ABSTRACT: Existing legal regimes for the management of water resources are already stressed by changing technologies and growing populations. There is little reason for doubt that today the planet is undergoing significant and even alarming climate change. In the past such global climatic changes had dramatic effects on water resource availability with disastrous consequences for many human communities. Today's climate changes can be managed without such disastrous consequences for present day communities only if there are major reforms to existing water law regimes at the local, national, and international levels. In particular, at the local and national levels, water resources must be treated as public property rather than as common or private property. At the international level, water must be managed at the drainage basin level rather than according to national boundaries that largely ignore rational water management criteria. At all levels, care must be given to decentralizing decision making and to use economic incentives insofar as possible, without, however, mistaking economic incentives for markets. The public nature of water resources precludes true markets as a significant management tool.  相似文献   

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Low impact development (LID) and other land development methods have been presented as alternatives to conventional storm water management and site design. Low impact development encourages land preservation and use of distributed, infiltration‐based storm water management systems to minimize impacts on hydrology. Such systems can include shallow retention areas, akin to natural depression storage. Other approaches to land development may emphasize land preservation only. Herein, an analysis of four development alternatives is presented. The first was Traditional development with conventional pipe/pond storm water management and half‐acre lots. The second alternative was Cluster development, in which implementation of the local cluster development ordnance was assumed, resulting in quarter‐acre lots with a pipe/pond storm water management system and open space preservation. The “Partial” LID option used the same lot layout as the Traditional option, with a storm water management system emphasizing shallow depression storage. The “Full” LID used the Cluster site plan and the depression storage‐based storm water management system. The alternatives were compared to the hydrologic response of existing site conditions. The analysis used two design storms and a continuous rainfall record. The combination of land preservation and infiltration‐based storm water management yielded the hydrologic response closest to existing conditions, although ponds were required to control peak flows for the design storms.  相似文献   

17.
ABSTRACT: According to a concept known as partial area hydrology, watershed areas are separated into hydrologically active and passive subareas. The literature relating to the development of the partial area concept is reviewed briefly and the relationship of partial area hydrology to geology, soils, and micrometeorology is illustrated. The potential application of partial area hydrology is discussed with respect to present hydrologic techniques, future hydrologic models, urban hydrology, water quality, and water management. Suggestions for identifying and delineating the contributing areas are discussed.  相似文献   

18.
This paper first examines the financial requirements for development of water resources in developing countries by 1990. Estimates of requirements for irrigation and drainage, community water supply and sanitation, hydropower, and assessment and planning are presented. In the second part of the paper some measures for mobilizing financial resources to meet indicated requirements are suggested. These include: choosing among available multilateral and bilateral assistance programmes at the international level; budgetary allocations and water pricing at the national level; and community participation at the local level. Dans un premier temps, cet article étudie les exigences financièes de la mise en valeur des ressources en eau dans les pays en développement jusqu'en 1990. Il fait l'évaluation de ces exigences dans les domaines de l'irrigation et du drainage, de l'approvisionnement en eau des communautés, de l'aménagement sanitaire, de l'hydroélectricité, de l'évaluation et de la planification. La deuxième partie du rapport présente des suggestions concernant la mobilisation de ces ressources financières pour répondre aux besoins susmentionnés. Celles-ci comprennent: les programmes d'assistance multilatérale et bilatérale au niveau international, les allocations budgétaires et la tarification d'eau au niveau national et la participation des communautés au niveau local. Este artículo examina primeramente los requerimientos financieros para el desarrollo de los recursos hídricos en los países en desarrollo hasta 1990. Se incluyen los estimados para irrigación y drenaje, suministro de agua potable, saneamiento e hidroelectricidad, así como para la evaluación y planificación. En la segunda parte del artículo se sugieren algunas medidas para la movilización de recursos financieros destinados a cubrir estos requerimientos. Estas medidas incluyen: la selección entre programas de asistencia bilateral y multilateral, a nivel internacional; asignaciones presupuestales para los recursos hídricos y tarificación, a nivel nacional; y participación de las comunidades a nivel local.  相似文献   

19.
Asserting that the major problem in water resources management stems not so much from a lack of alternative technologies as from a failure to make a choice which is appropriate to the several factors involved, the author addresses himself to these factors and to the criteria which should be applied in the decision-making process. Particular attention is devoted to a consideration of the incentives, and of the institutional, infra-structural, analytical and policy measures required to facilitate the adoption of 'socially optimal' technology, including the relationship of these measures to the promotion of effective water resources management technology within the broader economic, social and cultural situations specific to each country.  相似文献   

20.
ABSTRACT: As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations.  相似文献   

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