Electrical Resistivity Survey by Schlumberger Electrode Configuration Technique for Ground Water Exploration in Pakistan

Abstract

Aquifer zones had been explored by the geo-electrical method of electrical resistivity survey (ERS) to mark out subsurface formations in terms of groundwater quality and quantity. The main focus was on identification of subsurface litho-logy and aquifer zones by resistivity method in parts of the Havelian Cantt, Abbottabad district, Khyber Pakhtunkhwa (KPK) Province and Sanjwal Cantt, Attock district, Punjab Province, Pakistan. Evaluation of the lithology of subsurface strata was carried out by electrical resistivity survey (ERS) interpreted by software packages 1X1D using ABEM Terrameter SAS-4000. The different 05 sites were selected for ERS after identifying feasible locations. Data acquired was processed using the Schlumberger electrode configuration (SEC) to determine the characteristics of target layer. The results showed that groundwater level (GWL) at Havelian Cantt sites was at 69 ft average depth with resistivity values between 35-56 ohm-m and formation consist of dominance of gravel/boulder mixed with sand/ sand stone and thin layers of clay. GWL at Sanjwal Cantt sites was at 50 ft average depth having low to moderate yield of water and the formation had dominance of sand with alternate layers of clay against resistivity between 25-86 ohm-m. The study concluded that electrical resistivity survey (ERS) is a sound method for measuring GWL in sandy aquifers and boulder clayey formations when GWL is sufficiently deep