摘要:

ABSTRACT:Urban wastewater can be a valuable source of water and plant nutrients for agricultural producers, particularly in arid regions. The scientific literature reveals cautious optimism concerning the biological, institutional, and economic viability of irrigating crops with secondary‐treated effluent. A derived effluent demand function for agricultural producers near Tucson, Arizona, reveals a potential annual demand of 11,000 acre‐feet under present price and proposed delivery system conditions. In this case, wastewater could be exchanged for ground water and both the urban and rural areas would g

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00873.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:The water color in 14 lakes of diverse optical character has been computed from near‐surface upwelling irradiance spectra recorded by a submersible spectroradiometer. In these lakes the hues corresponding to irradiance spectra are in reasonable agreement with Munsell hue matches obtained directly by observation in the field. The simple field technique for hue matching using the Munsell standards was broadly validated by this spectroradiometric study. The technique is recommended for further study by limnologists and water resource managers as a potential additional tool for characterizing water

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00874.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:The Salmon Creek Watershed drains 325 km2of forested terrain in the Cascade Mountains of western Oregon. Over a 30–year period (from 1955 to 1984) average daily maximum and minimum stream temperatures, calculated from the 10 warmest days of each year, have risen 6°C and 2°C, respectively. In contrast, a small decrease in maximum air temperatures was found over the same period. Regression analysis indicated a highly significant (p<0.01) relationship between a cumulative index of forest harvesting and maximum stream temperatures. Maximum temperatures also tended to increase for several years following major peak flow events. The interaction between harvest activity (logging and road construction), changing forest and riparian management practices and the occurrence of natural hydrologic events (peak flows and associated mass soil movements) tend to obscure specific cause‐and‐effect relationships regarding long‐term changes in maximum stream te

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00875.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT; This paper presents a numerical model for the prediction of optimal ground water withdrawal from a two‐aquifer system by observing a set of constraints determined by the ecological conditions of the ground water basin. The aquifer system consists of an upper unconfined and a lower confined aquifer with a leaky stratum between them. It is assumed that water is withdrawn from the confined aquifer only, but the unconfined aquifer will also be affected due to the leakiness of the layer separating the upper and lower aquifers. Simulation and linear programming are employed for developing a computer model for the optimal management of such systems, with the objectives of determining withdrawal rates for predetermined ground water level

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00876.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:As part of the U.S. Environmental Protection Agency's effort to determine the long‐term effects of acidic deposition on surface water chemistry, annual runoff was estimated for about 1000 ungaged sites in the eastern U.S. using runoff contour maps. One concern in using contour maps was that a bias may be introduced in the runoff estimates due to the size of the 1000 ungaged sites relative to the size of the watersheds used in developing the maps. To determine if a bias was present the relationship between the annual runoff (expressed as depth) and the watershed area for the Northeast (NE) and Southern Blue Ridge Province (SBRP) was tested using five regional data bases. One short‐term data base (1984 Water Year, n = 531) and two long‐term data bases (1940–57, n = 134 and 1951–80, n = 342) were used in the NE. In the SBRP one short‐term database (1984 Water Year, n = 531) and one long‐term data base (1951–80, n = 60) were used. For the NE and the SBRP, runoff was not directly correlated with watershed area using the five regional databases. Also, runoff normalized by precipitation was not related to

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00877.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:Drought affects the quality of ground water in certain aquifers used by municipalities in Kansas. Water quality changes occur as a function of the amount of water available for recharge and hence to dilute more mineralized ground waters. Several measures of meteorological drought, including the Palmer Index and Eagleman Aridity Index, were correlated with water quality data to determine the degree of association. Several locations showed sharp delinces in water quality as the drought progressed. These relationships can be used to predict possible variations in present and future well‐water supplies in locations subject to drought induced water quality deterioratio

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00878.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:Landfill bottom liners are important elements in the analysis and design of solid waste disposal facilities. This study presents an overview of several models, describing the flow over and through liners. The examined models are compared against data from a laboratory investigation. A quasi‐steady state (QSS) and a transient (TS) model yield the most complete description of linear hydraulics, and allow for estimation of the system's collection efficiency. The TS model performed slightly better than the QSS model, although the latter has the advantage of simplicity. The hydraulic conductivities of the liner and the drainage layer and the leachate accretion rates are parameters whose magnitudes must be known with relative accuracy for good evaluation of system performanc

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00879.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:Irrigated agriculture is one of the most important water‐use sectors in terms of total water diversion and consumptive use. For at least the last 25 years, improving irrigation efficiency has been a widely advocated and accepted goal. This paper uses a sample of 16 Bureau of Reclamation irrigation projects to examine the pattern of average irrigation efficiency and change in efficiency over time. In general, the highest average efficiencies are found in the arid Southwest while the lowest are found in the semi‐arid to sub‐humid Great Plains region. Over the 22‐year period of analysis, there has been no observable trend toward improvement in efficiency at any of the p

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00880.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:The fish communities in three sewage receiving Illinois streams were monitored by electrofishing as treatment changed from secondary with chlorination to secondary without chlorination to tertiary without chlorination over a 40‐month period. Degradation of the fish communities was severe during the secondary treatment/chlorination period. When treatment was changed to secondary without chlorination, strong improvements occurred in the fish communities of all streams, and degradation could no longer be demonstrated on the basis of species number. The onset of tertiary treatment resulted in few additional changes in the fish communities, with the possible exception of increased abundance of several species of minnows. Tertiary treatment consisted of nitrification, sand filtration, and, in two streams, phosphorus remova

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00881.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACT:During the past two decades, the Kingdom of Saudi Arabia has witnessed rapid development in its agricultural and urban areas, which has resulted in greater reliance being placed on its ground water aquifers. The intensive development, particularly along the coastline and in the absence of adequate replenishment sources, has led to major deterioration in the quality and quantity of ground water resources.A numerical model of the Dammam aquifer in the Eastern Province is developed and used to predict the extent of the saline intrusion in the aquifer. The types of stresses effecting the solute transport were identified and remedial measures were suggested. (KEY TERMS: numerical modeling; Saudi Arabia; aquifer; modeling/statistics.)

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1988.tb00882.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY