Application of the Computer Method for Analysis of Pumping Test Data

Abstract

The hydrogeological parameters are most important for the quantitative study of any hydrogeologic system, and for optimal utilization of groundwater resources. Pumping-test analyses are mostly graphical; erroneous results of the computation of the hydrogeological parameters of an aquifer are generally due to individual judgement in the graphical analysis. Application of computers for aquifer evaluation comes under the inverse analysis technique and is based on the principle of least squares. The sum of weighed squares of differences between the observed drawdowns, and the drawdowns calculated using theoretical equations for the flow system under consideration. is minimized. The hydrogeological parameters in this case are treated as decision variables. This method can be applied to any flow system for which analytical expressions for the potential distribution are known. In this paper the method was applied to three pumping tests from aquifers of different flow systems. The values of storage coefficient and transmissivity arrived at. using analytical and digital computer methods, are tabulated (Table 1). The percentage differences are computed for both cases.