Delineation of groundwater resources using electrical resistivity tomography

Chandrabhaga basin of the Nagpur district is a part of the drought prone Vidarbha region of Maharashtra, India. This region is facing acute shortage of water for drinking and irrigation purposes. The basin is located at the eastern fringe of the Deccan traps consisting of volcanic rocks. Presently, dug wells penetrating composite layers of the weathered mantle and highly fractured rocks overlying stratified basaltic lava flows are the main source of water supply. However, water available in the dug wells is inadequate to meet the ever increasing demand for water causing considerable economic losses to the farming community. In the present work, we presented the results of an electrical resistivity tomography (ERT) survey carried out in the basin for the delineation of groundwater potential zones. Validity of the hydrogeological setup obtained from the ERT results has been confirmed by bore well drillings at two investigated sites. Groundwater zones are found to be in the depth range of 10 to > 100 m, under unconfined conditions at shallow depth to confined conditions within intertrappeans at deeper levels. The presence of Gondwana sedimentary formations (sand/sandstone/clay etc.) are also identified in some profiles. The study demonstrates the efficacy of the ERT technique in delineation of groundwater potential zones in the hydrogeologically complex basaltic terrain of the Deccan traps.

Figure: Electrical Resistivity models indicating different geological formations/structures for profiles P21 and P38 in the Basaltic terrain, Nagpur District Maharashtra; PW-Proposed bore well, GWZ-Groundwater zone.


Citation: Thiagarajan, S., Rai, S.N., Dewashish Kumar, and Manglik, A., 2018. Delineation of groundwater resources using electrical resistivity Tomography, Arabian Journal of Geosciences, 11: 212 (