Sensitivity analysis of pumping tests in non-uniform aquifers

Abstract

An approach for better understanding of the physical implication of estimated aquifer parameters is demonstrated by analysing the pumping test data at Cottam in the Nottingham aquifer, UK. A sensitivity ansalysis showed that the area represented by the estimated parameters was much smaller than the area covered by the depression cone. The sensitivity analysis also showed that the observed drawdown being satisfactorily matched by a model with uniform parameters does not prove that the aquifer is homogeneous. Although the drawdowns at Cottam could be "satisfactorily' fitted by a model with uniform parameters, the fit could be improved by a model using a more permeable aquifer but with a zone about 700 m wide and with 42% less transmissivity. -from Author