ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05206.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. Individuals and organizations concerned with the expansion of the facilities of a river basin (such as a river basin authority) need to determine optimal strategies of operation and capital investment. They also need to examine the sensitivity of whatever planning decisions are contemplated. This paper extends the applicability of an algorithm that had been previously applied to the deterministic river‐basin expansion problem to include the feature of a sensitivity analysis. The algorithm, containing a partial enumeration search technique and a network analysis code, gave a construction sequence of reservoirs, canals, and treatment plants, and an operating policy that maximized the present value of net earnings consistent with certain underlying assumptions. A river basin was chosen that had an existing configuration of unregulated streams and rivers, reservoirs, canals and treatment plants, and sites for future additional facilities.A series of representative synthetic flow sequences, future demand profiles, interest rates and reservoir costs that served as inputs to or parameters in the system were each perturbed by various factors (for a total of 24 cases). The sensitivity studies showed that theimmediateplanning decision of what facility to construct next was insensitive to variations in future demands and costs and independent of later decisions. Thus, decision‐making wasadaptivein the sense that by always making the optimal proximate decision, the management of the river basin is optimi

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05207.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. Two factors affecting the centralization of wastewater treatment facilities were investigated; the cost of collection and treatment systems and the performance of treatment plants. Based on computer‐generated minimum cost designs, wastewater collection networks were found to be characterized by diseconomies of scale of magnitude similar to the reported economies of scale for wastewater treatment works. The combined costs of collection and treatment are U‐shaped functions from which the least cost size of collection and treatment systems were found for particular values of population density. Examination of the day‐to‐day performance of five metropoitan‐area waste‐water treatment plants revealed that, for time series shorter than one month, the day‐to‐day variation in effluent quality was random, although the variation in quantity discharged was distinctly non‐random. The performances of all five plants on any given day showed little correlation. This suggests that the decentralization of treatment facilities can produce benefits both through the reduction in quantities of waste discharged at a given point and through in‐stream averaging of the varying performances of several treatment plants. Since the cost function of collection and treatment combined is generally flat in the region of the minimum‐cost size, little penalty is invoked to gain the potential benefits of treatment p

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05208.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. Federal guidelines for the establishment of water quality standards prohibit degradation of the properties of all or part of the nation's aquatic resources. It is probably correct that streams, lakes and aquifers should be free of toxic substances while non‐poisonous deposits should be abated. However, an extreme opposing position is held by some proponents of pollution who intend to continue discharging waste materials until forced to stop. Although it would seem otherwise, the underlying problem is that polluters' points of altercation possess merit in particular instances. Accordingly, efficient abatement will require that appropriate laws be formulated in such a manner that the nature of economic reasons for the disposal of waste materials be disclosed. Moreover, the technological ability to create byproducts from these particular elements or compounds can advance only over time. This, coupled with the fact that scientists have not developed inexpensive treatment methods which are totally effective, justifies more flexible formal regulations. Excessive rigidity of standards could impose a burden on polluters that is greater than the cost to society which the damaging firm or individual is generating. On the other hand, uniform rules in some cases could be considered so lenient as to allow flagrant contamination which unduly injures downstream user

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05209.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. The task of resource management, in this case water resources, is rapidly becoming more complex, particularly because decision making is often contingent upon various prior activities and sets of data. Comprehensive planning is required in order to prevent misallocation of resources or mismanagement in resource development. Such planning involves five general phases which are applicable to any problem faced by society: (1) problem identification; (2) formulation of alternatives; (3) evaluation of alternatives; (4) implementation; (5) review. There have been many attempts to simplify the planning process and effectively carry out these five phases. The experience of the Alberta Water Resources Division has been that the Critical Path Method is one of the most useful tools available today for planning. It involves two basic steps: (1) preparation of a network diagram which (a) identifies all the activities necessary for the completion of a project, (b) correctly sequences these activities, (c) allocates resources; and (2) mathematical computations for scheduling the activities. In other words, this approach breaks a task down into smaller units or activities for easier organization, scheduling, and performance for eventual completion of the project. This paper will illustrate the effectiveness of the Critical Path Method by discussing its application to actual water resources projects.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05210.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. Stream channel characteristics were found to be useful indices to the hydrology of 27 small forested basins in the Northeast United States. Channel width alone explained 37 percent of the variation in mean annual runoff, whereas channel width combined with basin area explained 78 percent of the variation in mean annual runoff. This approached the percentage of variation in mean annual runoff explained by mean annual precipitation (83 percent). A simulated 15% increase in precipitation, such as might occur in a weather modification project, produced increases in channel width, depth, and channel area of 3, 4, and 8 percent, respectively.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05211.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. The X‐ray fluorescence method was used to analyze trace metals collected in particulate form on filter papers and from the ionic state by ion exchange filter papers. The samples were prepared by allowing water to pass through these filter papers. The procedures necessary for using the X‐ray fluorescence method are described. A number of samples were taken from the Great Miami River in Dayton, Ohio over one year showing the presence of the following metals, Ca, Ti, Cr, Fe, Cu, Zn, Sr, and Cd. Elements in the periodic table between Ti and Cs were detectable to a sensitivity limit of the order of 30 ppb for metals in the particulate form and 0.4 ppm for metals in the ionic f

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05212.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. Silver iodide is currently the most favored cloud seeding material in weather modification projects. While the literature indicates that its ecological effects are likely to be insignificant, its disposition in the terrestrial ecosystem after snow melt has not been adequately studied. Silver levels in soil, plant and litter material are being monitored twice a year on a mountainous area in southwestern Colorado, to determine whether annual accretion from cloud seeding can be measured with current techniques and whether significant changes in silver concentration take place in grass, aspen, and spruce communities. One AgI generator site is also being monitored.Comparison of silver concentrations in terrestrial components of the target area indicates no measurable increase after the first winter's seeding. On an ash basis, spruce foliage and litter contain about four times as much silver as soil. On a dry weight basis, soil from all three plant communities contains about six times as much silver as foliage. Consistent increases in silver concentration were found in soil and pine foliage within 200 meters of one generator site.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05213.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. Decisions among water resources planning alternatives must consider, along with engineering and economics, a variety of environmental and social effects which are viewed and weighted differently by different interest groups. This paper briefly discusses present methods of project evaluation and then describes an approach adapted from highway planning literature for evaluating both monetary and non‐monetary variables and presenting them to decision makers at all levels. Social and environmental consequences are analyzed and presented using a graphical description called a “factor profile,” which measures in appropriate units all relevant non‐monetary effects of each alternative. Then, using the factor profile and engineering‐economic analysis, a series of paired comparisons are made to obtain a preference ranking among alternatives. Since preference decisions are extremely complex, a step by step procedure to simplify the decision‐making process is described. A case example considering four proposed flood control alternatives with the relevant environmental and social impacts is given to illustrate the use of the factor profile and the decision makin

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05214.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

ABSTRACT. In the last decade much research has been devoted to applying the systems analysis approach to water resources problems. A popular research goal has been determination of the “best” method of operating a multipurpose reservoir. The goal of this study was to derive the economically optimum flood control diagram for a multipurpose reservoir by systems analysis. The technique employed to optimize the flood control diagram was programmed so that the optimization process could be applied to other multipurpose reservoirs. Two computer programs developed at the U.S. Army Corps of Engineers' Hydrologic Engineering Center were utilized with modifications to simulate the operation of Folsom Reservoir in central California. Economic analyses were incorporated along with an optimization technique into the reservoir operations program; and the resultant program was capable of routing a sequence of monthly reservoir inflows, computing benefits for various flood control diagrams (as dictated by the optimization procedure), and selecting the economically optimum flood control diagram. The univariate gradient technique was the optimization procedure employed. The two computer programs are on file at the Hydrologic Engineering Center in Davis, Califor

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1972.tb05215.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY