Electrical Resistivity Survey to Delineate Groundwater Potential Zones in Granitic Terrain, Nalgonda District, India
Vertical Electrical Soundings (VES) with Schlumberger configuration were conducted in order to delineate groundwater potential aquifer zones in Wailpally watershed area, Nalgonda district, Andhra Pradesh, India. The entire area is underlain by granite and gneissic complex. Locating favourable groundwater zones in granitic terrain is a very difficult task, as the secondary features developed in hard rocks like faults, fractures, lineaments and dykes control the groundwater flow and movement. Therefore, there is always a need for locating and pinpointing the favourable location in hard rock areas. In order to assess groundwater potential zones, 59 vertical electrical soundings
(VES) with 100 to 200 m current electrode separation were conducted in the watershed area. Interpreted VES data were correlated with the drilled borehole logs and used to generate iso-resistivity maps like top layer resistivity, depth to the bed rock and longitudinal unit conductance maps. Based on VES interpreted data groundwater potential maps have been prepared showing good, moderate and poor zones.
Bhimasankaram, V.L.S., Bindi Madhav, U., Pantangay, N.S. and K.V. Ranga Rao (1970). Electrical resistivity investi- gation for groundwater in parts of Hyderabad district. Proc Sem Incidence of Aridity and Drought in Andhra Pradesh, Andhra University, Waltair.
Bhimasankaram, V.L.S. and V.K. Gaur (1977). Lectures on exploration geophysics for geologists and engineers. Association of Exploration Geophysics, Centre for Exploration Geophysics, Hyderabad.
Chand, R., Chandra, S., Rao, V.S., Singh, V.S. and S.C. Jain(2004). Estimation of natural recharge and its dependency on sub-surface geoelectric parameters. Journal of Hydrology, 299: 67-83.
Jupp, D.L.B. and K. Vozoff (1975). Stable iterative methods of inversion of geophysical data. Geophy. J. Ras., 4
(Implemented by T. Harinarayana on VAX 11/750 at NGRI).
Keller, G.V. and F.C. Frishcknecht (1966). Electrical methods in Geophysical prospecting. Pergamon, London, p. 517.
Mailet, R. (1947). The fundamental equations of electrical prospecting. Geophysics, 12: 529-556.
Orellana, E. and H.M. Mooney (1966). Master tables and curves for vertical electrical sounding over layered structures. Interciencia, Madrid, Spain, p. 150 (66 tables).
Todd, D.K. (1959). Groundwater hydrology. Wiley, New York, p. 538.
Yadav, G.S. and T. Lal (1989). Investigation of groundwater resources at selected levels in drought prone area of Pahari block, Mirzapur District, U.P., India. In: International Workshop Appropriate Methodology, Development, Management Groundwater Resources in Developing Countries, Vol. 1. NGRI, Hyderabad, India, 28 February-4 March 1989, pp. 209-219.
Zohdy, A.A.R. (1974). Application of surface geophysics to groundwater investigations. US Dept Interior, Geological Survey Book No. 2.