Non‐steady‐Flow Type Curves for Strip Aquifers with Constant Drawdown

Abstract

A type‐curve method to determine aquifer parameters from a constant‐drawdown test at a drain in a finite strip aquifer is described. An available solution in the form of complementary error functions to one‐dimensional, non‐steady flow toward a drain, under constant drawdown condition in a strip aquifer bounded on the other side by an impervious formation, is used to define a drain function. Values of the drain function are calculated by using a polynomial approximation for the complementary error function and are tabulated, and a corresponding family of type curves is constructed for selected values of dimensionless distance along the width of the strip aquifer. The method is demonstrated through an application. The proposed match‐point procedure may be used to determine the aquifer parameters from observed drawdown values in an observation well in the strip aquifer and discharge data measured in the drain during constant drawdown canal pumping tests.