New method for estimating aquifer parameters according to the data of water level recovery in pumping test

A new method for analyzing the data of water level recovery in pumping test is proposed. In order to derive the equations for estimating aquifer parameters, simplifications of the well function are suggested. Two terms in the expansion of well function are taken as the approximation of the well function describing the drawdown caused by imaginary continuing pumping, and the first three terms are taken as the approximation of the well function describing the drawdown caused by imaginary recharging with the same flow rate in pumping stage at the moment of pumping stopping. Based on these simplifications the methods for estimating the transmissibility and storage coefficient of aquifer according to the data of drawdown-time and drawdown-distance are established.