Fluctuations in groundwater level and corresponding earth resistivity changes

Abstract

The earth resistivity at a known location was frequently measured, through resistivity sounding. Resistivity of subsurface layers could be influenced by the permeability, porosity, transmissivity, composition etc., where moisture content was the concern of this study. ABEM-Terrameter SAS 1000 instrument was used for surveying and data were interpreted using “IPI2-win” software. A borehole was established to reveal accurate subsurface stratification information and monitor the groundwater level, at the surveying location. Groundwater level was recorded through a datalogger in the borehole, at each 12 hour interval. The precipitation data of the area were obtained from the meteorological department to understand the wet & dry seasonal characteristics. Attempts were made to identify the changes in apperant resistivity data in response to the changing groundwater levels/moisture content and the accuracy of corresponding layer thicknesses, computed through resistivity data.