Cooley and Case Solution for Leaky Aquifers
A mathematical solution by Cooley and Case (1973) is useful for determining the hydraulic properties (transmissivity, storativity and leakage parameters) of a leaky confined aquifer with a water-table aquitard. Analysis involves matching the Cooley and Case solution to drawdown data collected during a constant- or variable-rate pumping test.
AQTESOLV provides visual and automatic methods for matching the Cooley and Case solution to pumping test data. This easy-to-use and intuitive software promotes rapid and accurate determination of aquifer properties.
The following assumptions apply to the use of the Cooley and Case solution:
- aquifer has infinite areal extent
- aquifer is homogeneous, isotropic and of uniform thickness
- potentiometric surface is initially horizontal
- aquifer is confined
- flow is unsteady
- wells are fully penetrating
- 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
- confining bed has infinite areal extent, uniform vertical hydraulic conductivity, storage coefficient, specific yield and thickness
- flow is vertical in the aquitard
AQTESOLV provides the following options for the Cooley and Case solution:
- constant or variable pumping rate with recovery
- multiple pumping wells
- multiple observation wells
Cooley, R.L. and C.M. Case, 1973. Effect of a water table aquitard on drawdown in an underlying pumped aquifer, Water Resources Research, vol. 9, no. 2, pp. 434-447.