ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05757.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05758.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

ABSTRACTA mathematical model was developed to solve a steady free surface flow problem and a rapid drawdown problem in a two‐dimensional porous medium. The same problem was also solved by an analogue device and excellent agreement was found to exist between the two solutions. This paper contains the formulation of the numerical problem from first principles and a discussion of measures that had to be taken in order to assure numerical stability and proper convergence of the solution.Although the scope of this study was limited to a two‐dimensional flow case, the elements of simulation discussed are general in nature and applicable to three‐dimensional problems. It was demonstrated that numerical solution can be obtained for the position of the free surface at given time intervals, for the piezometric head distribution within the flow field and for flow quantities across given boundaries. In addition, the mathematical model will permit consideration of nonhomogeneous or anisotropic characteristics of the porous medium, without difficulty.It is concluded that mathematical models, incorporating some or all of the techniques discussed in this paper, in conjunction with some analogue control device, can be very efficient and reliable tools for solving complex porous flow problems, including those which, so far, have eluded comprehensive analysis, due to physical and/or cost limit

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05759.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

ABSTRACTThis paper presents a sample design for selecting streams in an investigation of the relation between water pollutian and water based recreation expenditures. The design is a proportional sample of clusters of streams stratified in a two‐way scheme. The clustering is achieved by sampling 71/2 minute topographical maps, and the stratification by using measures connected with water pollution to classify the clusters. The design is based on considerations of economy in data collection and computational efficiency. A distinctive feature of the design is that data collected are to be used in a regression analysis. Thus, the sample size is determined by trying to achieve a given degree of precision for the regression coefficient

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05760.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

ABSTRACTA sizeable body of information has accumulated which indicates that waste disposal concentrations which merely permit survival of aquatic organisms may not permit them to function properly. Aquatic resource management groups and fisheries personnel are beginning to realize that temporary survival of fish and other aquatic organisms is really meaningless if they have aberrant behavior patterns, fail to reproduce, have poor growth rates, or are not able to function properly in other respects. However, most means of assessing sublethal effects require chronic exposures to the test material and use techniques that often require considerable expenditures for equipment, space, and personnel. In addition it is frequently desirable to have some quick assessment of the biological effects of various compounds before embarking on lengthy tests to determine whether the possibility exists of functional damage when fish undergo prolonged exposure to sublethal concentrations. The apparatus described in this paper furnishes a quick, relatively inexpensive assessment of the movement patterns of fishes and the suggestion is made that changes in activity may reflect deeper physiological stress.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05761.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

ABSTRACTThe United Nations Food&Agricultural Organization in cooperation with the Ministry of Agriculture of the Government of El Salvador, Central America, recently completed a 3‐year groundwater exploration, research and evaluation project in the lower basin of the Rio Grande de San Miguel.As no comprehensive water resources study had previously been conducted in El Salvador, this project served as a pilot example of a balanced, integrated, scientific approach to a regional evaluation. It combined surface and groundwater hydrology with surface geology, hydro‐meteorology, and sub‐surface exploration by means of drilling and geophysical techniques.This paper describes how the project was planned, financed, organized, implemented, conducted, and managed. It further describes inter‐relationships between the geological and engineering phases carried out from 1961 to 1964, and the results of the field and laboratory research. Finally, this paper presents a summary of recommended groundwater and valley development programs, and discusses briefly post‐project development programs resulting from the basic

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05762.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05763.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05765.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Book reviewed in this articleHuman Dimensions of Weather Modificationby W. R. Derrick SwellPerception of the Drought Hazard on the Great Plainsby Thomas F. SaarinenPlant Environment and Efficient Water Use edited by W. H. PierreScientific Problems of the Humid Tropical Zone Deltas and Their Implications: Proceedings of the Dacca Symposium; jointly organized by the Government of Pakistan and UNESCO, 1964Statistical Methods in Hydrology, Proceedings of Hydrology Symposium held at McGill University, 1966Isotopes in Hydrology, Proceedings of the Symposium held by the International Atomic Energy Agency and International Union of Geodesy and Geophysics, Vienna, 14‐18 November 1966The Fresh Water of New York State: Its Conservation and Use, Proceedings of Symposium held in Buffalo, New York in 1966; 255 pagesThe Technology of Fish Utilizationedited by Rudolf KreuzerWater and Wastewater Engineering, Vol. 2: Water Purification and Wastewater Treatment and Disposalby G. M. Fair, J. C. Geyer and D. A. OkunDetergentien und Öle im Wasser und Abwasser(Detergents and Oils in Water and Sewage), Hans Liebm

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05766.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1968.tb05767.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY