Electrical resistivity investigation for groundwater potential in lateritic plateau of Bamnoli Range, Satara District, Maharashtra

Abstract

The Bamnoli range in Satara district of Maharashtra is a lateritic plateau in India. The aim of this study is to measure the thickness of lateritic plateau so as to understand the groundwater potential zones beneath the surface in this region. In the studied region, lateritic formation is dominant and is underlain by weathered and fractured rocks followed by hard and massive basalt. To achieve the desired objective, resistivity studies are conducted in the region and a total of 10 vertical electrical soundings (VES) were carried out by using Schlumberger configuration with maximum electrode spacing of 200 m. Isoresistivity contour maps at 1 m, 2 m, 5 m, 10 m, 20 m, 35 m, 50 m, 70 m and 100 m depths are generated to decipher the resistivity distribution over eight horizons of Bamnoli lateritic plateau. Geoelectric pseudo sections are generated to study the vertical variation in geology and groundwater depth. The results reveal that a thin soil cover is present on the top of laterites. The laterites are exposed from surface up to about 40 m depth, beneath which weathered and fractured basalts and fresh basaltic basement are present. It can be inferred that potential aquifer zones are observed in weathered/ fractured environs of the study area.