An Overview of Six Decades of Research and Evolution in Resistivity Exploration for Groundwater in Hard-Rock Terrain of India
Exploration for locating suitable sites to get groundwater is also an old technique from the fifth century starting from Varahmihir's "Drukggargal Shastra" in which anthills, certain species of trees, and certain types of strata have been mentioned as indicators for groundwater. Around 1955–1956, news came to India about the use of geophysical equipment for exploration for groundwater. In 1956, the first symposium on groundwater was organized in New Delhi by the Ministry of Natural Resources and Scientific Research and the volume of proceedings was published by Central Board of Geophysics. The geophysical instruments for seismic and resistivity surveys used in oil exploration were bulky but had a good depth of investigation. The first resistivity meter in India was purchased around 1956–1957 by the Central Water and Power Research Station at Khadakwasla near Pune. Data acquisition became easier but interpretation with the help of standard two-layer and three-layer master curves was too theoretical especially in hard-rock terrain.