PARAMETER-ESTIMATION IN AN AQUIFER-WATER TABLE AQUITARD SYSTEM

The weighted least squares approach is used for the estimation of parameters in an aquifer-water table aquitard system. Six parameters are to be evaluated, namely: the equivalent transmissivity, degree of anisotropy and storage coefficient of the aquifer, and the leakage coefficient, specific storage and specific yield of the aquitard. The coupled aquifer-aquitard equations are solved by an iterative numerical procedure and the optimisation problem is solved by the sensitivity analysis technique. This method is applied to one hypothetical problem and two field pumping tests of 7 days duration.