NUMERICAL ANALYSIS OF TEST PUMPING DATA

Abstract

An optimisation based model has been proposed for identification and estimation of aquifer parameters. Para-meters are estimated by minimisation of the sum of the squares of residues and their hydraulic relevance (or irr- elevance) is confi;u-4by the analysis of varainces. The applicability of the model to real life data has been illustrated by using the published data of the Central Ground Water Board, (Manual 1982). The model apart from estimating the aquifer parameters, was able to confirm the presence(or absence) of physical features like vertical anisotropy, barrier boundaries and leakiness. The drawdowns for anisotropic unconfined aquifers were simulated -.by Neuman's theory. For barrier boundaries image well theory and Theis equation were used. For leaky confined aquifer Hantush's solution was used. The starting solution for optimisation was generally assigned as per the available graphical solutions. The reduction in the sum of squares of residues through optimisation was significant in all the cases. The CPU time requirement was not proi.bitive from any standard,.