An attempt to understand the subsurface variation along the mountain front and riparian region through geophysics technique in South India

Abstract

Geophysical resistivity survey was conducted in 35 locations along the foothills of Courtallam, Tamilnadu, in order to depict the groundwater potential zone. The layer parameters like apparent resistivity (ρa) and thickness (h) of different layers were arrived. A maximum of four layers were identified in few regions, but major part of the study area is dominated mainly by three layers. Three major zones has been delineated as weathered, fractured and massive. Generally, A, H, KH type curve are dominant in this region and minor representation of HK is also observed. Resistivity and thickness of both the layers show decreased value in riparian zone. More resistivity and thickness along mountain front (MF) indicates good groundwater potential. The observed high conductivity in Southern part is symptomatic of the contaminated groundwater leached and drained into the subsurface from the agricultural regions. VES 6 and 13 along MF and VES 1, 3 and 12 along riparian zone are the probable locations for productive groundwater abstraction. Resistivity values and their corresponding depth for some selected VES locations were used in producing two resistivity cross sections (A–B, C–D), which show the geoelectric distribution of the subsurface near and away from the MF.