ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00721.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTThe hydraulic properties of commercial well screens were investigated to determine which screen design features affected head loss. The test program began with laboratory experiments and continued as a field‐scale experiment with the installation of a well field in the Thames Valley Gravel Aquifer.The laboratory experiments indicated that, for all practical purposes, the head loss attributable to all of the screens tested was negligible. The experimental head loss, however, did vary from screen to screen, particularly at high intake velocities, and the screens could be ranked on the basis of their hydraulic efficiencies. This efficiency hierarchy is explained tentatively in terms of the screen construction methods and slot geometry. The field experiments showed that the hydraulic performance of all well screens is independent of screen designprovidedthat the open area of the screen is above about 10%. The field experiments also indicated that the development capacity of a screen in a gravel aquifer is not wholly dependent on screen design, but that progressive development does increase the hydraulic efficiency of a wel

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00722.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00724.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00725.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00726.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTBased on 13 aquifer infiltration tests at 11 sites, aquifer transmissivity ranged from 17,000 to 40,000 square feet per day, and the streambed infiltration rate ranged from 0·06 to 0·19 million gallons per day per acre along a seven‐mile reach of the Scioto River in south‐central Ohio. Despite these wide ranges, the sand and gravel aquifer, 40 to 65 feet thick, underlying 10–20 feet of river alluvium south of the glacial boundary, is fairly homogeneous due largely to the absence of till interbeds.Performance of a major well field designed on the basis of the tests has been about as predicted, validating the techniques of data collection and analysis.At each site, a well for pumping was drilled on the floodplain, 150 to 750 feet from the river, and an array of observation wells was installed on lines extending through the pumped well, one line perpendicular to the river and the other parallel.Values of drawdown measured in the observation wells at the end of constant‐rate pumping periods, usually of three days duration, were used to determine line‐source distance and aquifer transmissivity. The rate of streambed infiltration and the streambed‐leakage factor, the latter term relating the infiltration rate to drawdown beneath the stream, also were determined at all but one site. Drive‐point wells installed in the riverbed, or along the near bank, in the vicinity of the pumped well were used to determine drawdown beneath the river

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00727.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTThe Pearl Harbor aquifer, an important ground‐water resource for southern Oahu, Hawaii, contains an enormous fresh‐water lens, up to 300 m (1,000 ft) thick, floating above saline water. The upper boundary of the fresh‐water lens is confined near the coast and phreatic inland, whereas its lower boundary is not confined. A finite‐difference flow model was used to simulate the Pearl Harbor aquifer system. The location of the fresh‐water/salt‐water interface, which constitutes the lower boundary of the flow system model, was estimated by Hubbert's formula. Known geohydrologic boundaries and aquifer parameters were also simulated. First, formation of the lens by filling the aquifer with fresh water from natural recharge was simulated to reconstruct the initial conditions before exploitation of the lens and to partially calibrate the model against the hydraulic‐head distribution in 1879. The model then was calibrated fully by simulating the lens’reponse to actual historical pumping patterns covering a time span of 100 years (1880 to 1980). Simulated heads compared favorably with the observed heads over time and space. The calibrated flow model may serve as a useful tool in the management of the Pearl

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00728.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTTime‐series techniques have been widely used in economic and environmental contexts. This paper explores their use in ground‐water systems. The basic techniques are considered in relation to hydrogeology and two case histories show their application to real systems. Water level fluctuations in a well field are shown to be dependent upon pumping rates and prior rainfall and can be simulated by a multiple linear regression model. The rate of dewatering of a mine is shown to be dependent upon pumping rates and prior rainfall and can be simulated by a multiple linear regression model. The rate of dewatering of a mine is shown to be dependent upon antecedent mine size and rainfall, and can also be simulated by a multiple linear regression model. Such models can be used for forecasting and control of the ground‐water systems, and once formulated are ideally suited to the management of ground‐water systems where more costly and complex methods cannot

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00729.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTMost underground coal mines in Illinois are relatively dry despite their location in saturated rock lying hundreds of meters below the water table. This is probably due to the low permeabilities of the rock units associated with the coal seams. Little is known about how mines affect the groundwater system, so it is difficult to predict where a mine is likely to encounter an influx of ground water.To obtain information on the hydrogeological character of the roof rocks, an array of piezometers was installed in roof‐bolt holes at two locations within an underground coal mine in central Illinois. Pressure vs. time measurements were obtained from piezometer arrays located in areas of the mine ranging from dry to wet conditions. Data collected from the piezometers indicate that water drainage from a saturated sandstone above the coal is largely controlled by local structural and stratigraphic features, and these features determine the distribution of wet and dry areas in the mine. Hydraulic conductivities of the sandstone were determined in the laboratory and in situ from drainage profiles and from tests of instantaneous head changes. Results of these tests indicated that dewatering in front of mining would not be successful in this min

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00730.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTSignificant amounts of brine produced in conjunction with oil well operations in the Greater Altamont‐Bluebell field have been disposed of to surface impoundments. Mass balance calculations indicate that about 93% of this brine, a total of 4,430 acre‐feet (5·45 × 106m3) over the ten‐year period studied, is lost through seepage, introducing a total salt load of 200 million pounds (90 × 106kg) into the shallow aquifer system. Estimates of salt‐water plume movement indicate that potential adverse economic impacts on irrigators and other water users in the Duchesne River Valley could reach hundreds of thousands of dollars. Lining of disposal ponds and increased use of injection wells will reduce future contamination. A monitoring program should be set up to determine actual levels of contamination of domestic and agricultural wate

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1983.tb00731.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY