Vol.:(0123456789) 1 3 Environmental Earth Sciences (2018) 77:626 https://doi.org/10.1007/s12665-018-7813-8 ORIGINAL ARTICLE Mapping lithological variations in a river basin of West Bengal, India using electrical resistivity survey: implications for artifcial recharge K. Pratima Panda 1  · S. P. Sharma 1  · Madan K. Jha 2 Received: 4 December 2017 / Accepted: 4 September 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Groundwater is a treasured earth’s resource and plays an important role in addressing water and environmental sustainability. However, its overexploitation and wide spatial variability within a basin and/or across regions are posing a serious challenge for groundwater sustainability. Some parts of southern West Bengal of India are problematic for groundwater occurrence despite of high rainfall in this region. Characterization of an aquifer in this area is very important for sustainable development of water supply and artifcial recharge. Electrical resistivity surveys using 1-D and 2-D arrays were performed at a regular interval from Subarnarekha River at Bhasraghat (south) to Kharagpur (north) to map the lithological variations in this area. Resistivity sounding surveys were carried out at an interval of 2–3 km. Subsurface resistivity variation has been interpreted using very fast simulated annealing (VFSA) global optimization technique. The analysis of the feld data indicated that the resistivity variation with depth is suitable in the southern part of the area and corresponds to clayey sand. Interpreted resis- tivity in the northern part of the area is relatively high and reveals impervious laterite layer. In the southern part of the area resistivity varies between 15 and 40 Ωm at a depth below 30 m. A 2-D resistivity imaging conducted at the most important location in the area is correlated well with the 1-D results. Based on the interpreted resistivity variation with depth at dif- ferent locations diferent types of geologic units (laterite, clay, sand, etc.) are classifed, and the zone of interests for aquifer has been demarcated. Study reveals that southern part of the area is better for artifcial recharge than the northern part. The presence of laterite cover in the northern part of the area restricts the percolation of rainwater to recharge the aquifer at depth. To recharge the aquifer at depth in the northern part of the area, rainwater must be sent artifcially at depth by puncturing laterite layers on the top. Such studies in challenging areas will help in understanding the problems and fnding its solution. Keywords Groundwater · Geoelectrical structures · Resistivity soundings · Artifcial recharge · Laterite Introduction Water is the most important natural resource for living beings. Day by day the availability of water decreases due to expanding agriculture, increasing population and growing industrialization. Most of the surface water is not sufcient for the requirements of human beings, so the groundwater plays an important role for every living being. Rapid use of groundwater for irrigation and domestic purposes decreases the groundwater levels. To supply sufcient water, in water shortage areas, artifcial recharge is extremely important these days. Artifcial groundwater recharge is a basic tool to maintain a certain level of essential freshwater resources (both surface water and groundwater). From last few dec- ades, restoring the groundwater through artifcial recharge has been carried out in various parts of the world (Babcock and Cushing 1942; Beeby-Thompson 1950; Buchen 1955; Todd 1959; Asano 1985; Jasrotia et al. 2007, etc). The knowledge of subsurface structures is extremely important for construction and development of artifcial groundwater recharge schemes in any area. Numerous stud- ies were carried out on the surface (using remote sensing and GIS) and subsurface (using electrical resistivity method) on artifcial recharge (Eid et al. 2006; Ghayoumian et al. 2007; Jasrotia et al. 2007; Acharya et al. 2017, etc.). Gener- ally remote sensing and GIS interpretation yields surface information and it does not give any information about the * K. Pratima Panda kpratimapanda@gmail.com 1 Department of Geology and Geophysics, IIT Kharagpur, Kharagpur, West Bengal, India 2 Department of Agricultural and Food Engineering, IIT Kharagpur, Kharagpur, West Bengal, India