Delineation of potential aquifer zones in gneissic terrain using multi-electrode scanning technique—case study in part of Chittar sub-basin, South India

Abstract

To understand the sub-surface lithology variation and identify possible groundwater potential zones, multi-electrode resistivity scanning was carried out at 7 locations in the part of Chittar sub-basin, Tirunelveli District, South India. Physiographically, the selected study area is a plain and falls under the semi-arid climatic type. Archaean crystalline of hornblende biotite gneiss and charnockite are the major rock types, pediments and buried pediments are the major geomorphological units. A length of 100 m was scanned using 50 electrodes with interspacing of 2 m by SSR-MP-AT-ME model resistivity meter and analysed in IPI 2WIN software. The data obtained from resistivity showed huge resistivity variations in areas where Narikudi, Rastha, Therkkupatti and Vagaikulam locations represented ≤ 1000 Ohm m and Alagiyapandiapuram, Muthamalpuram and Nilethanallur locations represented 9000 Ohm m. To validate the scanning interpretation, constructed geoelectric layers were correlated to existing lithology of the region and it showed an appreciable match. Considering the resistivity range of 50 to 120 Ohm m and bore well lithology, Narikudi and Muthamalpuram locations have been identified as potential groundwater zones while Nilethanallur, Rastha, Therkkupatti, Alagiyapandiapuram and Vagaikulam locations were also identified as low to moderate groundwater zones.