Delineation and validation of GIS-based groundwater potential zones under arid to semi-arid environment using multi-influence-factors approach

Groundwater is an indispensable source for domestic-use, agriculture, industry and sustainable development. Groundwater scarcity is Pakistan’s emerging issue, especially in the arid and semi-arid regions of southern Khyber Pakhtunkhwa. This study intends to demarcate the groundwater potential zones (GWPZ) in these regions using Multi-Influence-Factors (MIF), validated with Vertical Electrical Sounding (VES) and well data. The study region was classified into four GWPZ: very high (340 km2), high (4997.11 km2), moderate (17615.14 km2) and poor (16355.46 km2). These interpretations were supported by the VES survey, and water bearing layers have been recognized at 32 m, 137 m, 87 m, 10 m at VES points 1, 2, 3, and 4, respectively in Karak, and at 152 m, 194 m, and 93 m at VES points 1, 2, and 3, respectively in Lakki Marwat, while at 125 m, 119 m and 80 m at VES points 1, 2 and 3, respectively in D. I. Khan. The southern region is predominantly poor, the northern and northeastern parts are high to very high, while the southwest part has moderate potential. Water depth is <40 m at very high potential, 40 to 70 meters at high potential, and 150 to 180 meters in poor zones. This study will help to enhance the applicability of integrated methodologies for groundwater investigations under arid conditions.