A hydro-geophysical investigation of groundwater potential

Abstract

The electrical resistivity method is being employed for hydro geophysical investigation of groundwater. This technique will provide an insight into the nature of subsurface formations. Wenner configuration of electrode arrangement is mostly practiced the resistivity observations. Resistivity observations were taken with vertical electrical sounding (VES). An estimate of the resistivity and thickness of various subsurface layers at a location could be obtained by successively increasing electrode spacing. The inverse of the resistance measured 1/R was plotted against Wenner electrode separation on a linear graph. Even thin layers at deeper layers could be detected. IGIS signal stacking resistivity meter model SSR-MP-ATS was used to obtain the pattern of aquifer distribution in KCAET campus and to delineate possible sites for drilling tube wells. The subsurface formations in the campus were found to be basically rocky. But certain areas like near the volley ball court (location), near the carpentry workshop, near canteen, near men’s hostel, confined aquifers of weathered rock formation could be seen. A confined aquifer with a thickness of 13 meters and resistivity 199 ohm-m extending from 4 to 17meters was observed near the carpentry workshop. Weathered formations of resistivity 123 ohm-m was obtained at a depth of 16m near volleyball court. The area near the farm office was found as potential sites for filter point tube wells. No water bearing formations could be identified along the western boundary of the campus were the residential buildings are located. The water scarcity in the campus can thus be overcome by utilizing the ground water available at the potential areas identified in this work.