Delineate Subsurface and Groundwater Investigation of Ongur Watershed, South India

Abstract

The electrical resistivity technique is extremely supportive to investigate the nature of subsurface lithology by understand the variations in their electrical properties. The Vertical Electrical Sounding (VES) technique by Schlumberger electrode array applied in 77 Locations at Ongur River Sub Basin in Tamil Nadu, India. The Signal stacking Resistivity Meter Model SSR-MP-ATS has been applied to gather the VES data by employed a Schlumberger array, one end current electrode (AB/2) ranging from 1 to 100 m, other side placing potential electrode (MN) from 0.5 to 10 m. The concept of the VES data interpreting is the foundation of IPI2Win. It means for a VES data are treated as a unity representing the geological structure of the Ongur River watershed. The output Geo-electrical layers, iso- resistivities and thickness of this area were prepared in spatial maps by using ARCGIS software. Consequently, the following zones with different resistivity values are detected consequent to different formations: (1) identification of lithology Ongur River Sub Basin, (2) layer saturated with fresh groundwater, (3) determine saltwater horizon.