GEOPHYSICAL INVESTIGATION IN THE BHULESHWARI RIVER BASIN, AMRAVATI DISTRICT, MAHARASHTRA.

Abstract

Detailed geophysical investigations were carried to characterize the subsurface geological structure for the alluvial aquifer in the Bhuleshwari river basin, Amravati District, Maharashtra. The Bhuleshwari river basin covers an area about 380 Sq. Km. from Bhatkuli and Achalpur Taluka, Amravati district, Maharashtra. It ows over varied geological formation from Deccan trap to Alluvium with groundwater quality varying from fresh water to saline water. Twenty VES's were recorded with the Schlumberger electrode conguration in the study area for evaluation. The maximum current electrode spacing was 120m. The data obtained were interpreted by computer iterative modeling with curve matching for calibration purposes. Three layer, four layer and ve layer geoelectrical earth models are obtained with the help of IPI2 WIN for every sounding, which represents Ktype, KH type, AA type, KQ type, HK-type, HA-type, HKH-type curves. These curves are used to nd out favorable locations of occurrence of ground water. In order to ascertain the subsurface geological framework, the general distribution of resistivity responses of the geological formations was obtained and geoelectrical sections along four different directions were prepared and interpreted for subsurface structure and groundwater occurrences. Geoelectrical sounding provides an inexpensive technique for calculating the hydraulic parameters and characterizing the aquifer system of the basin. Probable aquifer horizons from these sections were identied.