Butler Solution for Confined Aquifers with Nonuniform Properties
Description
A mathematical solution by Butler (1988) is useful for determining the hydraulic properties (transmissivity and storativity of two zones) of confined aquifers with nonuniform properties. The solution assumes the pumping well is located at the center of a disk embedded within an infinite matrix. Hydraulic properties are assumed uniform within each zone (disk and matrix), but may differ between the two zones. Analysis involves matching the Butler solution to drawdown data collected during a pumping test.
AQTESOLV provides visual and automatic methods for matching the Butler solution to pumping test data. This easy-to-use and intuitive software promotes rapid and accurate determination of aquifer properties.
Assumptions
The following assumptions apply to the use of the Butler solution:
- aquifer has infinite areal extent
- aquifer is heterogeneous with a disk embedded within a matrix
- control well is fully penetrating
- flow to control well is horizontal
- aquifer is confined
- flow is unsteady
- water is released instantaneously from storage with decline of hydraulic head
- diameter of control well is very small so that storage in the well can be neglected
Solution Options
AQTESOLV provides the following options for the Butler solution:
- variable pumping rates
- multiple observation wells
References
Butler, J.J., Jr., 1988. Pumping tests in nonuniform aquifers—the radially symmetric case, Journal of Hydrology, vol. 101, pp. 15-30.
See also: solution methods, pumping tests