Groundwater prospecting in Deccan traps covered Tawarja basin using Electrical Resistivity Tomography
Acute shortage of water supply for domestic and irrigation purposes in hard rock area is accentuated by occurrence of groundwater in limited quantity within sparsely distributed aquifers characterised with secondary porosity of finite areal extent. Tawarja river basin is in drought prone Latur district of India falling in basaltic Deccan Volcanic Province (DVP). which occupies half a million square km area. Because of availability of limited quantity of groundwater in the shallower aquifers, ever increasing withdrawal of groundwater in excess to recharge is resulting in continuous declining of water table. As a result bore wells/ dug wells used for groundwater pumping from shallower aquifers often go dry, with the onset of summer season. Locating of groundwater potential zones by bore well drilling, in the absence of scientific investigations, is fraught with high percentage of failure. Therefore, delineation of deeper sources of groundwater with certainty based on scientific investigations is urgently needed to meet the ever increasing demand for water supply. This paper presents results of 2-D Electrical Resistivity Tomography carried out in part of Tawarja basin, a complex geo-environ, to demonstrate its efficacy in delineation of groundwater potential zones and sites of aquifer recharging. Several sites suitable for bore well drilling have been identified, which can be developed to meet the water supply demand in the investigated region.