Resolution enhancement for geoelectrical layer interpretation of electrical resistivity model from composite dataset: Implication from physical model studies

Abstract

Besides the high resolution offered by HERT, the resistivity models obtained using different electrode arrays differ significantly in geological structure and resistivity range. We combine the apparent resistivity data from multiple arrays to provide single resistivity model of high resolution as 'composite method'. Initially, the method was tested on physical model data obtained over horizontal marble sheet kept in water. The parameters of target (resistivity, geometry, thickness) noticed in the resistivity model corresponding to composite method are appropriately matching with the true parameters. Finally, the method was applied to the data from Mahabubnagar, Telangana, India for groundwater studies. The resistivity model obtained using the proposed method has shown good match with regional hydro-geology and borehole data. The results from physical model as well as field data suggest plausible resolution enhancement in composite methodology for resolving thin layer(s) in 2D and 3D electrical resistivity tomography and induced polarization (IP) studies.