The Study of Potential Groundwater Recharge Zones Using GISBased Fuzzy Analytical Hierarchical Process (FAHP) Technique: A Case Study of Northern Dezful, Iran

The study area is located in northern Dezful City, adjacent to Dez dam, in southwest of Iran and has variable groundwater potentials. Correct understanding of groundwater potential is essential for water resources management and sustainable use. Groundwater potential mainly depends on the amount of recharge. Lithology, slope, topography, weathering, porosity and vegetation are among the factors which influence recharge. Due to the large number of influencing factors on recharge and capabilities of Geographic Information System (GIS) in managing large amounts of spatiotemporal data from various sources, this tool was employed for preliminary studies. In order to increase judgment accuracy and flexibility in finding the highest natural recharge potential of the area, GIS was integrated with Fuzzy AHP. In the first place, factors influencing groundwater recharge were identified and weighted based on existing standards. The resulting zonation map was then used to identify areas with the highest penetration rate. Results showed that central and western parts of the area have the highest penetration rates, while areas adjacent to the northern parts have the lowest effect on groundwater recharge. It was also concluded that lithological variations caused by sedimentation conditions and fault activities, control groundwater potential among different geological formations and within each formation.