Delineation of the Aquifer in the Curin Basin, South of Zahedan City, Iran

ABSTRACT

Resistivity method using 596 Schlumberger vertical electrical soundings along 26 profiles are conducted in the Curin basin, Iran to investigate the sub-surface layering and aquifer characteristics. The results of quantitative and qualitative interpretation of data reveal four layers. The true resistivity of the top soil varies from 3 to 800 ohm-m while the thickness varies from 0.5-15 m. The second layer (dry alluvium) is thicker than the surface layer with resistivity values less than 100 ohm-m. The third layer, which constitutes an aquifer, has resistivity values of less than 10 ohm-m and depth values of less than 30 m in most locations. The maximum depth of aquifer is 60 meters in the northwest and southeast portion of the study area. The fourth layer (bedrock) is characterized by two electric resistivity values ranges. In most parts of the area, it is more than 60 ohm-m, corresponding probably to slate, while in other areas, it is less than 60 ohm-m, corresponding probably to shale. Finally from the quantitative interpretation of VES curves, the limits of the aquifer were determined.