摘要:

A field irrigation experiment and computer and statistical models are used to estimate the functional relationships between the total soil water suction and the man‐controlled variables, the quantity and salinity of the water, and the irrigation frequency. It is estimated that the seasonal average soil water suctionSin the root zone increases with each of the variables: the irrigation interval, water salinity, and initial soil salinity. The value ofSalso increases with the amount of irrigation waterQat low values ofQ, but decreases withQat relatively high values ofQ. Under the conditions studied, it is more efficient to use given quantities of irrigation water (from the standpoint of salinity) for changing the soil water regime rather than for leaching. An approach to the economic evaluation of the optimal combination of water quantity and salinity in the short run is outlined. This approach is based on a previous empirical estimate of the effect of water suction on yield, and on the present estimate of the functional relationships between the total soil water suction and the man‐controlled irrigation variab

ISSN:0043-1397    

DOI:10.1029/WR008i004p00791

年代:1972

数据来源: WILEY

摘要:

Market forces have failed in the areas of development, allocation, and management of natural resources in general and water resources in particular. The shaping of public investment programs for the development of water resources has long been dominated by partial equilibrium analyses such as benefit‐cost analysis. However, this approach is rather limited for an interregional and intertemporal management program of water resources. The present study offers a multisector planning and management approach to water resources that is based on a general equilibrium analysis employing input‐output models and linear programing techniques. A dynamic multisector programing model that takes into account the sectoral, spatial, and temporal aspects of regional planning and an extension to an activity analysis model are formulated and applied empirically to California and the western United States for a 15‐year planning horizon. The results of the empirical application include water requirement forecasts, interregional water transfer requirements, efficient production and cropping patterns, ‘shadow prices’ for water and labor, and an optimal investment program for water resource projects. The use of a general equilibrium programing model has made it possible to investigate problems of regional development that are dependent on the interrelationships between resource availabilities and sectoral planning and has illustrated the importance of the complex interdependencies among economic

ISSN:0043-1397    

DOI:10.1029/WR008i004p00801

年代:1972

数据来源: WILEY

摘要:

Projected long‐range demands on the Nile water resources for irrigation, as found in the literature, are compared with estimates of the mean flow. Existing overyear storage capacity is taken into account. The possibilities for increasing the quantity of water that could be used are discussed. The cooperation between the Nile basin states in respect to their water resources is describe

ISSN:0043-1397    

DOI:10.1029/WR008i004p00818

年代:1972

数据来源: WILEY

摘要:

Conventional methods of forecasting the future demand for municipal water supply give undue emphasis to historical rates of use, ignore many relevant factors, and fail to distinguish between components of use. This study is concerned with only the residential part of urban water use, and a forecasting model or framework for analysis is proposed. Six factors influencing future water use are regulations on the water used by appliances, type of pricing policy adopted, policy on public education, future housing patterns, cost of supply, and changes in the technology of use. Two or three outcomes are considered for each of these factors, and from combinations of these outcomes alternative descriptions of the future are formed. The cities of Baltimore and Phoenix are used as case studies to illustrate the method. For each case, a base line estimate is made that reflects past trends. The effect on the water use of each alternative future is estimated and the probabilities of each outcome are subjectively assigned. Thus a probability distribution of the future water demand is drawn.

ISSN:0043-1397    

DOI:10.1029/WR008i004p00829

年代:1972

数据来源: WILEY

摘要:

Recreation studies have in the past confused the terms demand and use. Demand refers to the schedule of quantities that the community will desire at all possible prices. Use or participation is the realization of both demand and supply considerations. Accordingly, a priori information in addition to the data must be supplied prior to the estimation of economic models of the recreation market. The identification problem assesses the sufficiency of such information. Since the type of information and the data themselves impose constraints on the specification, estimation, and use of economic models of the recreation market, a taxonomy of each applied study framed around a general equilibrium model of recreation decisions is presented, and the specific applied studies are discussed. A clear outline of the logical structure connecting the theoretical model with its empirical realization results from this taxonomy.

ISSN:0043-1397    

DOI:10.1029/WR008i004p00840

年代:1972

数据来源: WILEY

摘要:

Regional water quality management by a three‐level optimization approach is developed. Proposing the construction of a regional treatment plant, the central authority determines simultaneously the optimal treatment configuration for meeting water quality standards along a river basin and the optimal effluent charges necessary to realize this configuration. The optimal regional plant capacity and regional treatment level are also found, depending on which polluters decide to use the regional facilities. It is assumed that the central authority does not need to know the local treatment cost functions. Numerical results from simulated use of the technique with data for the Miami River basin reveal the efficiency and the effectiveness of the multilevel approach. Considerable savings over local treatment alone can be realized by employing regional treatment facilitie

ISSN:0043-1397    

DOI:10.1029/WR008i004p00851

年代:1972

数据来源: WILEY

摘要:

A simulation model is developed and used for evaluating the reliability of supplying a known demand pattern in a given water supply system in which shortfalls are caused by random failures of the pumping equipment. An economic model is presented that enables one using the reliability model to compute the cost of the marginal water obtained by improving the reliability of the system and to determine the desirability of the improvement from this cost computation. Results are presented from the initial tests of the reliability model, in which the sensitivity of the reliability to various variables was examined. The results of applying the reliability and economic models to an existing water supply system are presented and discussed.

ISSN:0043-1397    

DOI:10.1029/WR008i004p00861

年代:1972

数据来源: WILEY

摘要:

The probability mass function of peak streamflow from a given catchment is derived from the density functions for climatic and catchment variables by using the functional relationships provided by the kinematic wave method of hydrograph forecasting. The exceedance probability for a flood peak of given magnitude is then related to the annual exceedance recurrence interval of this flood. The resulting theoretical flood frequency relation shows a changing form with change in catchment and climate parameters and agrees well with observations from three Connecticut catchments. It provides a theoretical basis for estimating flood frequency in the absence of streamflow records and for extrapolating empirical estimates based on short records. Because of the explicit appearance of physically meaningful catchment parameters it also allows quantitative estimates of the effect on flood frequency of changes in average land use. The flood frequency relation for a given catchment is averaged across the population of catchments of given size to provide a theoretical regional flood frequency function that compares favorably with observations of mean annual floods on 44 Connecticut catchments.

ISSN:0043-1397    

DOI:10.1029/WR008i004p00878

年代:1972

数据来源: WILEY

摘要:

Two common purposes for which multipurpose reservoirs are operated are water supply and flood alleviation. Apportioning the available reservoir storage between these interests requires a compromise since their storage requirements are in direct conflict. The lack of a suitable basis for optimizing this apportionment has led to the use of a ‘satisficing’ model in which priority has been given to water supply: rules were then developed to optimize the operation of the reservoirs with respect to the secondary purpose, flood alleviation, provided the primary purpose is fulfilled to a predetermined standard. The resulting control policy is being applied to the River Dee system in Wales, which comprises two multipurpose reservoirs and one direct supply reserv

ISSN:0043-1397    

DOI:10.1029/WR008i004p00899

年代:1972

数据来源: WILEY

摘要:

The purpose of the long‐term control strategy is to define retention levels for a multipurpose reservoir that permit maximum storage to be available for flood alleviation subject to shortages in its water supply function occurring with a specified tolerable frequency. A recursive relationship is derived to calculate the probability of no shortage occurring within a chosen interval of time for any given set of retention levels. This relationship is used in conjunction with an iterative search procedure that finds the optimal set of minimum retention levels necessary to meet a given demand with a specified acceptable frequency of failure, and thereby as much storage as possible is allowed for flood alleviatio

ISSN:0043-1397    

DOI:10.1029/WR008i004p00904

年代:1972

数据来源: WILEY