Interpretation of Pumping from Two‐Zone Layered Aquifers Using a Numerical Model

A numerical model is presented which represents both the radial and vertical flow components which usually result from pumping from boreholes in layered aquifers. This model, which is based on finite‐difference approximations, runs on a microprocessor system and can be used for the analysis of pumping test results. A discussion on the interaction between the radial and vertical flow components is followed by a description of the model. A computer program in BASIC and a typical computer output are provided. The application of the model for the analysis of a pumping test in a weathered‐fractured aquifer is described. Three case studies are reviewed where the numerical model is used to gain a greater understanding of the aquifer flow processes.