Selected Procedures for Analyzing Aquifer Test Data

Abstract

Over the years, therefore, the USGS has developed quite a large store of qualitative and quantitative geologic and hydrologic methods of study. In this paper, it will be possible to demonstrate only a select few of the many methods used in determining the hydrologic characteristics of ground water reservoirs.

Hydrology of Brookhaven National Laboratory and vicinity, Suffolk County, New York

“…The results are presented in table 7. The theory and practice of aquifer performance tests, made by testpumping a well screened in an aquifer, have been adequately described in several reports (Brown, 1953;Bruin and Hudson, 1955 A pumping test is made on a pumped well, usually of large capacity, which should be under the experimenter's control. In the preliminary stage this well is shut down so that conditions in the aquifer to be tested may come to equilibrium.…”

Ground-water resources of the Dayton area, Ohio

“…In this method the effects of pumping a well at a known constant rate are measured at several observation wells that tap the same aquifer. Graphs of drawdown versus distance from the pumped well, or of drawdown versus time since pumping started, are used to solve equations that express the relation between the coefficients of transmissibility and of storage of an aquifer and the lowering of water levels in the vicinity of a pumped well (Brown, 1953).…”

A brief appraisal of ground-water conditions in the Coastal Artesian Basin of British Guiana, South America

“…The hydraulic properties of an aquifer are expressed by the coefficients of transmissibility (T), permeability (P), and storage ($), which have been described by Wenzel (1942), Brown (1953), and others. Several methods have been developed by Thiem (1906), Theis (1935), Jacob (19401950), Ferris (1952, and other?…”

“…The second method used is the Theis nonequilibrium formula (Theis, 1935), known as the type-curve solution (Brown, 1953;Wenzel, 1942). Coefficients of transmissibility and storage are obtained by plotting values of drawdown (s) in the observation well versus values of the radius (distance between wells in feet) squared…”