摘要:

Economic uncertainty programing (Ecup) is a method which enables decision makers to analyze economic uncertainties in the design of water resources systems separately from hydrologic uncertainties. Ecup distinguishes between economic and hydrologic variables in the expression of a payoff or objective function. The economic variables, assumed to have been estimated at discrete points only, are treated as random variables. A postulated joint probability distribution of these variables is used to estimate by Monte Carlo simulation the distribution of payoff resulting from a project. The worth of perfect information or expected opportunity loss is calculated. In a case study the problem of choosing among flood protection levees of different heights is examined. The random economic factors considered are the flood losses and construction costs. The sensitivity to various degrees of error correlation and loss uncertainty is analyzed. It is found that a relatively small uncertainty in the economic estimates of the payoff function may cause considerable variance in both the distribution of benefits to be expected from a levee and the height of the optimal levee.

ISSN:0043-1397    

DOI:10.1029/WR012i004p00573

年代:1976

数据来源: WILEY

摘要:

The problem of determining the optimal number, location, and level of treatment for regional domestic sewage treatment plants along an estuary or river is considered. The formulation is one of minimizing the sum of treatment and transport (piping and pumping) costs such that water quality improvement goals for dissolved oxygen are met. Restrictions may also be placed upon the overall level of treatment (required secondary, required uniform, or least cost) if desired. An optimization procedure is developed which utilizes dynamic programing, linear programing, and heuristic location techniques in a series of steps which lead to progressively improved (lower total cost) solutions. The location procedure is intended for use by an engineer‐planner during the design stage and requires his participation and skilled judgment during the course of the algorithm. The technique is illustrated for the Delaware estuary for 22 domestic waste sources, nine potential regional sewage treatment plant sites, and 22 industrial waste sources. Results of the case study show considerable savings over previous nonregional treatment scheme

ISSN:0043-1397    

DOI:10.1029/WR012i004p00581

年代:1976

数据来源: WILEY

摘要:

A probabilistic Markov model of reservoir state transitions is developed which, in combination with a simulation model, offers a computational tool for estimating response surface gradients of water resources planning problems. Use of the gradient estimation capability provides a substantial improvement in efficiency of the search for improved water resources configurations. The estimation capability arises by recognizing and using the reservoir state transition changes that would result from a modification of decision variables. The procedure is highly flexible in that it functions under such complicated situations as multiple‐objective environments, nonlinear benefit loss functions, and complex connectivity of river basin component

ISSN:0043-1397    

DOI:10.1029/WR012i004p00592

年代:1976

数据来源: WILEY

摘要:

This paper examines two alternative schemes for pricing irrigation water. Under the first scheme, price is independent of weather; in the second scheme, price varies with weather so as to generate just enough demand to exhaust reservoir capacity. The second scheme provides savings through the more efficient utilization of available reservoir supplies and through the curtailing of demand so as to allow the construction of smaller reservoirs. The analysis proceeds by means of a linear programing under uncertainty model of a representative farm. The model is applied to the High Plains of Texas. Results suggest that the weather‐dependent pricing scheme would increase farm profits by the order of 10% per annu

ISSN:0043-1397    

DOI:10.1029/WR012i004p00599

年代:1976

数据来源: WILEY

摘要:

Reservoirs provide storage capacity which serves to match more ideally the demands and supplies of water. The amount of storage required very critically depends upon the constraints on freeboard, minimum pool level, and upon the permissible limits on releases. Release policy also plays a very critical role. During the recent years, one of the policies which has attracted a great deal of attention is what has come to be known as the linear decision rule policy. This policy passes on the variability of a particular period's inflow to the next period's release. This paper offers another release policy, which is called the δ release policy, where δ is a parameter whose value distributes the effects of inflow variability between the releases and the pool level. This paper shows that δ release policy requires smaller reservoir capacity than that obtained by the linear decision rule poli

ISSN:0043-1397    

DOI:10.1029/WR012i004p00606

年代:1976

数据来源: WILEY

摘要:

A unique water pollution data base for the U.S. coastal waterways and Great Lakes that has been evolving since 1965 is discussed in this paper. The pollution statistics in this data base are used to develop a model, using multiple discriminant techniques, to determine which pollution incident report variables will discriminate the polluter who reports his spill from the polluter who does not report his spill. The results of the analysis as given in this paper indicate that as few as nine variables, out of a possible 60 variables, provide reasonable discriminatory power.

ISSN:0043-1397    

DOI:10.1029/WR012i004p00613

年代:1976

数据来源: WILEY

摘要:

The basic structure of the Techcom planning methodology is reviewed. In the context of this system a weighting methodology is developed to measure preferences regarding the attainment of postulated societal goals. The selected methodology, the Metfessel general allocation test, is applied to the hierarchies of three Techcom goals relating to aesthetics, economics, and recreation. The weighting methodology is tested with answers to a mail questionnaire randomly distributed throughout Arizona and New Mexico. Examples of the resulting preference weights are presented, and the use of such measures by decision makers discussed.

ISSN:0043-1397    

DOI:10.1029/WR012i004p00617

年代:1976

数据来源: WILEY

摘要:

This study examines the summertime evaporation from a shallow lake in the Hudson Bay lowlands evaluated by the energy budget (Bowen ratio) and equilibrium model approaches. Energy budget calculations reveal that on the average, 55% of the daily net radiation is utilized in the evaporative process over the lake. Half‐hourly and daily values of evaporation were approximated closely by the Priestley and Taylor (1972) model, where the ratio of actual to equilibrium evaporation equals 1.26. A simple model, expressed in terms of incoming solar radiation and screen height air temperature, is developed from the comparison of actual to equilibrium evaporation. Tests of the model at a different location indicate that the actual evaporation can be determined within 10% over periods of 2 week

ISSN:0043-1397    

DOI:10.1029/WR012i004p00623

年代:1976

数据来源: WILEY

摘要:

Probabilistic linear programing techniques and Bayesian statistics are combined in this paper by utilizing an example from the area of irrigated agriculture and water supply forecasts to assess the value of increased forecast accuracy to decision units. The case studied was confined to a two‐period analysis involving (1) a crop planting period and (2) a growing and harvesting period. The model is developed in terms of Bayesian analysis and demonstrates how linear programing can be applied to rather complex decision making problems involving uncertainty. Testing of the model involved the use of an IBM computer program available at the University of Michigan. For various assumptions as to supplemental water supply the model showed a net benefit to irrigators of about $6/acre for a reduction in uncertainty of 33% resulting from the introduction and improvement of water supply forecast

ISSN:0043-1397    

DOI:10.1029/WR012i004p00629

年代:1976

数据来源: WILEY

摘要:

Two one‐dimensional models based on the Dupuit‐Forchheimer assumptions to simulate flow beneath strip oceanic islands are presented. A model which is here designated the continuously moving interface (CMI) model is solved by finite differences. The solution agrees well with an analytical solution for a particular case given by Collins (1976). Because of its long response time the CMI model is not able to simulate short‐term fluctuations in water level in a well located on the South Fork of Long Island, New York. A second model, designated the delayed interface response (DIR) model, can reproduce the average hydrograph of the well and the decline in water level during most of an extended drought. However, because the model requires discontinuous movement of the interface between freshwater and salt water, some error is introduced into the solutions. The DIR model is used to predict the response of water levels to modifications in recharge patterns on the South Fork of Long I

ISSN:0043-1397    

DOI:10.1029/WR012i004p00640

年代:1976

数据来源: WILEY