Parameter Estimation for Step-Drawdown Tests

Step-drawdown tests may be used to evaluate the well loss component of the well drawdown and to obtain estimates of the aquifer properties. A procedure that analyzes step-drawdown tests with pumping stages of unequal time durations was formulated and developed into a computer program; the method is applicable to confined aquifers where the water-level drawdowns are governed by the Theis well function. A least-squares-fit error analysis is used in the determination of the aquifer properties and the well loss component of the drawdown.