Evaluation of the aquifer of research farm of Islamic Azad University of Behbahan using geoelctric resistivity method

Geoelectric resistivity method as the vertical electrical soundings using Schlumberger configuration is the most applied method in hydrogeology survey. In this research, ۱۲ vertical electrical soundings along ۴ profiles were carried out in order to evaluate the aquifer of the research farm of Islamic Azad University of Behbahan located at around ۵ kilometers from the east of Behbahan city. The interpretation of the field data was carried out using the Russian software IPI۷.۶۳ with consideration of well logs and geology data of the area; so the depth and thickness of the subsurface layers of the area were determined. Also, the isoapparent resistivity maps, geoelectric sections, maps of the isodepth and isoresistivity of aquifer and bedrock as well as the isotransverse resistance map have been drawn. Based on geoelectric model, in this area, ۴ main layers are obtained involving dry alluvium with the average resistivity about ۳۵۰ ohm-m and the average thickness of ۱۸.۸m, aquifer with the average resistivity about ۳.۳ ohm-m and the average thickness of ۸.۶ m, bedrock layer with the average resistivity about ۴۲ ohm-m (between ۶.۸ to ۳۷ ohm-m in most parts of area) and the average depth of ۲۷ m and a low resistivity below the bedrock with the average resistivity about ۲.۱ ohm-m and the average depth of ۶۳m. The transverse resistance map of aquifer that correlate to transmissivity is used to determine zones with high yield potential of the aquifer and the best location for well drilling in the area.

Keywords:

Geoelectrical surveys , Ground water exploration , Schlumberger array , Vertical electrical sounding