Delineation of Saline/Fresh Water Interface and Mapping Groundwater Potential Zones using Spatial Resistivity Models in Bichpuri Block Agra, District UP, India

Abstract

Pin-pointing freshwater within saline formations is of utmost importance as filtration and alternate means of public water supply are responsible for high expenditure. Vertical Electrical Sounding (VES) (n=49) was conducted at various locations in the Bichpuri block, Agra district. In this study for VES, the Schlumberger configuration was used. VES data were reconciled with the borehole well log, and drill sample cuttings were utilized to understand sub-surface configuration. Reconciled VES data displayed variation in resistivity layer parameters, i.e., layer thickness & true resistivity of sub-surface. True resistivity spatial models were developed at 25m intervals from the ground surface down to the depth of 150m, based on geo-electric parameters. Resistivity models reveal that freshwater is limited to 55m depth, beyond which groundwater is saline to brackish. The basement was encountered at a depth of 120m and further extended up to 150m. A groundwater potential map was prepared using GIS and divided into 3 categories–good, moderate, and poor. Major habitations of the study area lie in poor groundwater potential zone, which is a cause of concern with the intent on future development. Similar studies can be extended to areas with saline groundwater for mapping freshwater zones.