ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03552.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACTNonequilibrium pumping tests were performed at two widely separated sites consisting of one pumped and two observation wells each. The wells at both sites bottomed in the same stratigraphie formation; at one site a confined aquifer was tested, at the other the aquifer was unconfined. Data gathered from the tests were analyzed using the methods developed by Theis (1935), Jacob (1946), Chow (1952), and Hantush (1961). Eight separate determinations of transmissibility, permeability, and specific yield were made at each site. At the unconfined site, all eight determinations of permeability and transmissibility fell within nine percent of the mean of these calculated values. Specific yield predictions showed a wider variation, with individual computations differing by up to 55 percent from the mean at the confined site. No one method was found to yield consistently higher or lower values for the computed hydrologic characteristics; rather, the observation well used to make the analysis was found to have a more marked effect on the results obtained. Analysis of the well recovery curves confirmed the existence of local recharge near the test sites, explaining the apparent effect of the use of data from different observation wells on the analysis.

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03553.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACTProcedures are developed and charts are presented to determine the unsteady drawdown in a group of wells which are located along a straight line and fully penetrate a homogeneous, isotropic, artesian aquifer. Based on the linearity of the governing field equation, the principle of superposition is used to combine the effects of individual wells, and solutions are obtained by using a digital computer to evaluate an exponential integral. The concepts of equivalent radius, coefficient of interference, and degree of uniformity are introduced, and quantitative graphical relationships are given as functions of the independent variables, which are the number of wells, well spacing, and time.

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03554.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03555.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACTGround water is an important source of water supply in Czechoslovakia, and its use is very carefully planned because the resources are unevenly distributed. The supply is limited because Czechoslovakia is situated on the European water divide between the North, Baltic, and Black Seas, and all waters flow out of the State. The paucity of ground‐water resources, requiring assessment and classification of the utilizable ground water, has led to development of a State ground‐water resources zoning plan. Increasing demand for ground water has resulted in extensive and responsible hydrogeological research, contributing to a good knowledge of the ground‐water resources. Czechoslovak hydrogeology has been developed to a high level, even though it is a relatively young branch of science, and stands in some respects in the forefront of world hydrogeology, especially in prospecting, development and protection of mineral‐water resources, hydrogeological mapping, and ground‐wat

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03556.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03557.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACTIn the fall and winter of 1967–68, a 2,587‐foot test well was drilled at Moore's Bridges Filter Plant, Norfolk, Virginia. The well penetrated rocks of post‐Miocene, late and middle Miocene, late Eocene, Cenomanian, Cenomanian and Albian, Albian and Aptian, and Aptian and Neocomian age.Empirical data must be established in the Tidewater area for the successful calculation of ground‐water quality from calibrated geophysical logs. Chemical analyses of water samples from seven separate zones at depths between 850 feet to 2,500 feet below sea level indicate that the water type changes from a predominantly sodium bicarbonate water above 1,700 feet to a sodium chloride water in the deeper zones. The sodium bicarbonate type water in shallow aquifers must be corrected for divalent cation effects when using the self potential method or for the bicarbonate effect when using the resistivity method of interpretation.Using calibrated geophysical logs, an approximation of the dissolved‐solids and chloride content may be calculated using the formula Rw= Ro/Ffand the appropriate figures in the text. A field formation factor (Ff) of 4.2 is proposed for the Cretaceous aquifers in the Atlantic Coastal area. A K value of 84 should be used to check the validity of the magnitude of the self potential curve for the fresh‐ and brackish‐water aquifers in the Cretaceous. If the amount of dissolved solids is known for the Cretaceous waters, the chloride content may be approximated by the formula Cl = 0.5 (dissolved solids–300), provided the dissolved solids are less than 3,500 mg/l (milligrams per liter), and by the formula Cl = 0.6 (dissolved solids–400), if the dissolved solids are greater than 3,500 mg/l. In the Tidewater area, if the saturated resistivity (Ro) reading on the electric log is less than 25 ohmmeters the total solids and chloride content of the water are probably in excess of Public Health standards for potable water. An empirical method of calculating the quality of water from electric

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03558.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

ABSTRACTGround water in the arid coastal area of Peru occurs in more than fifty alluvial aquifers. The aquifers are limited to river valleys and to nearby sedimentary plains.The coast is rainless and the river valleys serve as the drainage outlet of the western slopes of the Andes. The coastal alluvial aquifers are located below the lower limit of the active catchment areas, and are not recharged directly by precipitation.The long igneous batholith and the volcanic formations of the Andean Cordillera form an impermeable barrier which prevents the replenishment of the aquifers by underflow from the Andes.The main source of replenishment of the aquifers in the Peruvian coastal zone is river water. The water infiltrates through the river beds and irrigation canals and migrates laterally within the alluvial deposits. Another important source of recharge is return flow from irrigation. Water also enters the aquifers through boundary faults.

ISSN:0017-467X    

DOI:10.1111/j.1745-6584.1971.tb03559.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY