摘要:

This paper details an application of mathematical programing to the problem of optimal water quality control in an estuary. The mathematical models allow for the possibilities of at‐source treatment, regional treatment plants, and by‐pass piping. Actual data from the Delaware Estuary are used to solve a large‐scale problem and the solution is given. The results indicate that a regional treatment system for the Delaware Estuary is superior, in terms of total cost, to other proposed sc

ISSN:0043-1397    

DOI:10.1029/WR008i002p00273

年代:1972

数据来源: WILEY

摘要:

In this paper the specification and estimation procedures of the response functions of crops to soil water content and salinity are presented. The conceptual framework is discussed, and the application of the suggested procedures is illustrated by an analysis of two irrigation experiments. The possibility of positive correlations between soil salinity, soil water content, and crop yield is discussed, and possible erroneous evaluations of the effect of salinity on crop yield in such situations are pointed out.

ISSN:0043-1397    

DOI:10.1029/WR008i002p00291

年代:1972

数据来源: WILEY

摘要:

The study indicates a significant microlocation relationship between water‐oriented manufacturing employment and water availability, where water availability is measured in terms of 7‐day, 10‐year minimum streamflow, in the 194‐county Tennessee Valley region. At the county level, chi square tests of independence indicate that concentrations of at least 500 employees in water‐oriented manufacturing (and increases of at least 250 over the period 1959–1968) are significantly related to water availability. Further, the data and tests suggest that a streamflow in the neighborhood of 400 cfs (cubic feet per second) is the critical or threshold flow necessary for the occurrence of such employment concentrations. To explain the variation in employment per river mile among small regions within the region, a regression equation with population density as the independent variable was constructed. The regression indicates that, for a difference of 10% in population density between small regions, employment per river mile vari

ISSN:0043-1397    

DOI:10.1029/WR008i002p00301

年代:1972

数据来源: WILEY

摘要:

The general problem of the feasibility criteria for interim water supplies is analyzed. Two forms are presented: (1) a combination of an interim supply and a long‐term supply and (2) the possibility of multiple interim supply projects and a long‐term supply. Both forms are compared with an immediate long‐term conventional water system. A problem formulation that yields to the optimal deferment period of the long‐term supply system is presented. The cost effectiveness of a combined desalting‐surface supply system is discussed, and a numerical example is presented. A table relating the different costs of the interim and long‐term projects with the water requirement is calculated. This table provides the optimal deferment period for the long‐term projects. The numerical results show that although the desalting system described clearly would not be competitive as a complete substitute for the surface system, the combination system of desalting for 10 years followed by the surface system is full

ISSN:0043-1397    

DOI:10.1029/WR008i002p00317

年代:1972

数据来源: WILEY

摘要:

A systems approach to land use management decision making in wildland areas is developed and demonstrated by using a hypothetical example. A major component of this systems approach is a chance‐constrained programing model for investigating the effects of risk and uncertainty on land use management decisions. The solution of the chance‐constrained model indicates the most efficient set of land use management activities for reaching specified goals subject to certain requirements and regulations. In addition to indicating the type and extent of land use management activities for a specific area, the systems approach provides additional results and conclusions concerning more general aspects of land use management decision making. The development and solution of the chance‐constrained model indicate that the risk and uncertainty associated with the system physical and economic parameters can significantly affect the design of land use management activities. The model results further suggest that future outdoor recreational demand and benefits are important factors in the design of land use management activities. The solution of the chance‐constrained model indicates that forest management practices to increase stream‐flows may have only a minimal effect on the design and operation of downstream r

ISSN:0043-1397    

DOI:10.1029/WR008i002p00326

年代:1972

数据来源: WILEY

摘要:

A chance constrained model of an irrigation reservoir is developed that employs a more general reservoir operating policy than previous chance constrained reservoir models. Development of this model demonstrates the possible convolution problems associated with chance constrained models of water resource systems. The optimal reservoir design and operating parameters resulting from model solution are investigated in a simple reservoir simulation model employing operational hydrology. Results of the simulation studies validate the chance constrained reservoir model.

ISSN:0043-1397    

DOI:10.1029/WR008i002p00339

年代:1972

数据来源: WILEY

摘要:

A study was conducted to give some perspective to the importance of accurate evapotranspiration (ET) input data to hydrologic models. For the analysis, computed output from three hydrologic models was considered as the true watershed response. Variations in the form of random fluctuations and fixed biases were introduced into the potential evapotranspiration (Pet) input data of the test models. By leaving the other inputs and parameters unchanged, such an analysis shows the effect of evapotranspiration on streamflow under the regulation of the other components in the model. It is shown that a constant bias of 20% in the Pet input data has a cumulative effect and results in considerable error in the computed hydrograph peaks and recession characteristics, whereas the influence of the random error on estimated streamflow was generally not measurable for the watersheds and models studied.

ISSN:0043-1397    

DOI:10.1029/WR008i002p00348

年代:1972

数据来源: WILEY

摘要:

The considerable influence of the masses of water in the Great Lakes on the weather over and around the Lakes is reviewed and the average lake‐related weather alterations are indicated. Particular emphasis is placed on delineating the known facts and those that are inadequately known. The lack of extensive continuous weather measurements, particularly over the lakes, makes definitive areal assessments of lake influences on the weather around them difficult. Whether the lakes act as the energy sources or sinks on a daily or seasonal basis depends on the relative temperature of the waters and the overlying air. Over the lakes and their downwind shore areas, the lake‐caused average changes in cloud and precipitation amounts represent 5–15% reductions in summer and 5–45% increases in winter in comparison with upwind

ISSN:0043-1397    

DOI:10.1029/WR008i002p00360

年代:1972

数据来源: WILEY

摘要:

Data from 38 airborne radiation thermometer (Art) surveys of Georgian Bay (a part of the Laurentian Great Lakes system) over a 4‐year period have been used to determine the areal patterns of surface water temperature and their seasonal variation. Although the limited observational period makes the resulting maps tentative, nevertheless definitive patterns have emerged. Of particular interest are the marked control of surface water temperature by water depth and the influx of cool surface water from Lake Huron during July and August. Ice is found on Georgian Bay from about mid‐December through to late April; the areal extent showed wide year to year variation with the maximum area ranging from 40 to 90% of the wh

ISSN:0043-1397    

DOI:10.1029/WR008i002p00372

年代:1972

数据来源: WILEY

摘要:

A 2‐year study of snowmelt in the Upper Peninsula of Michigan is summarized. The major results are (1) that although it was frozen in early winter, the ground thawed and remained unfrozen as snow accumulated from mid‐February on; (2) that the unfrozen ground allowed the production and infiltration of ground melt, which gave rise to a winter base flow twice that of summer; and (3) that a standard equation for predicting air‐snowpack moisture exchange was inadequate, especially when condensation occurred. It is proposed that this latter discrepancy is due to the occurrence of condensation just above, rather than at, the snow surface, so that the latent heat is released largely to the air rather than to the sno

ISSN:0043-1397    

DOI:10.1029/WR008i002p00390

年代:1972

数据来源: WILEY