Integrated approach for aquifer delineation in hard rock terrains - a case study from Banda District, India

Abstract

For obtaining a quick and stable solution of a groundwater problem in a hard rock area, totalling about 3000 km² in the southeastern parts of the Banda district of India, an integrated approach of photogeological, hydrogeological and geoelectrical studies was carried out with satisfactory results. The data of 160 vertical electrical soundings were interpreted using a computer oriented ridge-regression estimation technique, which provided a stable solution of the resistivity inverse problem even when the data are inaccurate and system parameters are linearly dependent. The integrated studies have indicated the existence of three aquifers in the subsurface: (a) a porous, sandy aquifer within the alluvium; (b) fractured (and weathered) aquifers in the sandstone bedrock in the eastern and southern parts, and in the granite bedrock in the northwestern parts of the area; and (c) a deeper aquifer in the cavernous dolomite, occurring below the compact sandstones, and expected to be highly productive at a number of localities. However, its southward extension beyond a lineament, designated as Manikpur Shear Zone, could not be established.