48-Flow Simulation through Multiple Leaky Aquifers.

Abstract

A mathematical model for well flow in multiple leaky aquifer system with bottom aquifer partially penetrated was formulated with initial and boundary conditions. Numerical solution to the flow governing equation was then obtained by using central difference formula and Successive Over Relaxation (SOR) technique. Computer programmes were written in FORTRAN to predict the drawdown distribution caused by a well penetrating one or more aquifers. For validation of the developed mathematical model, a semi-circular sand tank model was constructed and pumping tests were conducted to generate the required discharge drawdown data at various depths of penetrations. The data obtained by conducting the experiments were converted for the field conditions using dimensional analysis. Comparison between the observed and the predicted drawdown values has been presented to indicate the errors (deviations) with respect to distance, discharge and penetration ratios for the purpose of validation. The errors in prediction of drawdown for the bottom, middle and top aquifers range from 1.11 to 16.11% with a mean average of 5.25% only.