COMPUTER AIDED ANALYSIS OF PUMPING TEST DATA

Abstract

A model for computer-assisted analysis of pumping test data from confined and leaky confined aquifers for estimation of aquifer parameters has been presented. It is based upon the principle of minimization of weighted sum of squares of difference between observed and computed drawdowns (weighted least squares). A two step iterative procedure for assigning weights has been used. The drawdowns are computed using Theis equation for confined aquifer and Hantush-Jacob's equation for leaky confined aquifer. Minim izaton is accomplished by random search method which is a non-gradient optimization technique. The application of the proposed model has been illustrated by analysis of a pumping test data set each from a confined and a leaky confined aquifer. The model computed parameters honoured the observed data quite closely. Apart from parameter estimation, the model can assist in identifying the observation well whose data honour the chosen drawdown equation more closely.