NON-STEADY-FLOW TYPE CURVES FOR STRIP AQUIFERS WITH CONSTANT DRAWDOWN

A type-curve method to determine aquifer parameters from a constant-dr awdown test at a drain in a finite strip aquifer is described. An avai lable solution in the form of complementary error functions to one-dim ensional, non-steady flow toward a drain, under constant drawdown cond ition in a strip aquifer bounded on the other side by an impervious fo rmation, is used to define a drain function. Values of the drain funct ion are calculated by using a polynomial approximation for the complem entary error function and arc tabulated, and a corresponding family of type curves is constructed for selected values of dimensionless dista nce along the width of the strip aquifer. The method is demonstrated t hrough an application. The proposed match-point procedure may be used to determine the aquifer parameters from observed drawdown values in a n observation well in the strip aquifer and discharge data measured in the drain during constant drawdown canal pumping tests.