An inverse procedure to estimate transmissivity from heads and SP signals

Experimental hydraulic heads and electrical (self-potential) signals associated with a pumping test were usedin an inverse model to estimate the transmissivity distribution of a real aquifer. Several works reported in the literatureshow that there is a relatively good linear relationship between the hydraulic heads in the aquifer and electricalsignals measured at the ground surface. In this experimental test field, first, the current coupling coefficientwas determined by the best fit between experimental and modeled self-potential signals at the end of the pumpingphase. Soon afterward, with the hydraulic heads obtained from the self-potential signals, the transmissivity distributionof the aquifer was conditioned by means an inverse model based on the successive linear estimator (SLE).To further substantiate the estimated T field from the SLE analysis, we analyzed the drawdown rate, the derivativeof the drawdown with respect to the ln(t), because the drawdown rate is ...