GEOELECTRICAL SOUNDINGS AND THEIR RELATIONSHIP TO HYDRAULIC PARAMETERS IN SEMIARID REGIONS OF JALORE, NORTHWESTERN INDIA

Geoelectrical soundings using the Schlumbeger configuration were carri ed out in the close vicinity of twelve pumping test sites in the Jalor e district of Rajasthan, India, to relate geoelectric and hydraulic pa rameters. Geoelectrical sounding data were interpreted by partial curv e matching technique to obtain the initial model parameters. This init ial starter model was then used to obtain the final layer parameters t hrough inversion technique. From the inversion technique, the best-fit ting, lower bound (minimum) and upper bound (maximum) models were deri ved under 1% error level. The best-fitted models were correlated with the litholog. The resistivities for most of the aquifer zones are foun d to be very low which may be due to deteriorating quality of groundwa ter besides their packing and grain size. The resistivities of collect ed water samples were determined to compute the formation factor and p orosity. Computed formation factor and porosity were correlated with h ydraulic conductivity. The formation factor is directly related to hyd raulic conductivity whereas porosity is inversely related. The normali sed aquifer resistivity was correlated with hydraulic conductivity and normalised transverse resistance with aquifer transmissivity. The hyd raulic conductivity is found to be closely related with normalised res istivity and the transmissivity with normalised transverse resistance. (C) 1998 Elsevier Science B.V.