Site Selection of the Underground Dam using the Analytical Hierarchy Process and Geographic Information System (Case Study: Shahrekurd and Marghmalek Watersheds)

Underground dams are structures blocking the natural flow of groundwater and provide groundwater resources. In arid regions with limited water resources, it can be managed by constructing these structures. The purpose of this study was to select suitable site for the construction of underground dams in ShahreKurd and Marghmalek watersheds based on site selection criteria. As several different criteria should be considered, it is essential to use methods that are capable of fulfilling the desired criteria. For this purpose, GIS and Analytical hierarchy process (AHP) were used in this research. To prioritize the areas, different criteria and sub-criteria such as water (quantity, quality), reservoir (reservoir depth, reservoir slope, permeability and reservoir area), axis (axis length, axis depth and lithology of the supports) and socio-economic factors (distance from rural areas, distance from road, drinking, agricultural and industrial water supplies, and impact on water resources) were considered. The water quantity with a weight of 0.83 had the highest rank. Finally, 15 regions were introduced for prioritization out of 60 suitable sites in the study area using Boolean logic. The results showed that the best axes for underground dam construction were located in alluvial beds of low slope, high-flow rivers, with large reservoir volume, high runoff, and high permeability.