Abstract:
Groundwater is water that exists in the pore spaces and fractures in rocks and sediments beneath
the earth’s surface. The Electrical Resistivity method was used for the hydro-geophysical
investigation of groundwater resources in coconut garden of Horticulture College so as to
discover a sustainable source of water, to meet the various requirements of the campus. The
main objectives of the present project were to conduct hydro-geophysical investigation of
groundwater potential and to obtain aquifer distribution within the study area in order to
delineate possible sites for drilling tube wells for irrigation water supply. A special technique
called ‘Resistivity Scanning’ is found to successfully delineate the fractured geometry of
formation. This technique will provide an insight into the nature of subsurface formations.
Wenner configuration of electrode arrangement is mostly practiced for 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.
From the eight locations under consideration, none of the locations could serve as potential
groundwater sources. By the analysis of 2 -D cross-section of strip resistivity ,to identify site
favourable for recharge structure, we can arrive at the conclusion that a continuous soil layer
of average depth 10 m was observed at the top.Major portion of area was occupied by a
continuous layer of crystalline rock formation which extended up to 80m depth. Beyond
crystalline rock, there was a layer of continuous metamorphic formation which could not
provide sufficient water. By this study, all possible sites in the coconut garden were explored
for the presence of ground water. The project could come to a conclusion that, potential areas
for sustainable water supply were not available in the coconut garden.
