Geoelectrical soundings and their relationship to hydraulic parameters in semiarid regions of Jalore, northwestern India

Abstract

Geoelectrical soundings using the Schlumberger configuration were carried out in the close vicinity of twelve pumping test sites in the Jalore district of Rajasthan, India, to relate geoelectric and hydraulic parameters. Geoelectrical sounding data were interpreted by partial curve matching technique to obtain the initial model parameters. This initial starter model was then used to obtain the final layer parameters through inversion technique. From the inversion technique, the best-fitting, lower bound (minimum) and upper bound (maximum) models were derived under 1% error level. The best-fitted models were correlated with the litholog. The resistivities for most of the aquifer zones are found to be very low which may be due to deteriorating quality of groundwater besides their packing and grain size. The resistivities of collected water samples were determined to compute the formation factor and porosity. Computed formation factor and porosity were correlated with hydraulic conductivity. The formation factor is directly related to hydraulic conductivity whereas porosity is inversely related. The normalised aquifer resistivity was correlated with hydraulic conductivity and normalised transverse resistance with aquifer transmissivity. The hydraulic conductivity is found to be closely related with normalised resistivity and the transmissivity with normalised transverse resistance.