A regional-scale hydrogeological study for identifying karstic aquifers with high water resource potential in Iran

Abstract

This study has been carried out with the aim of identification of areas of extensive karstification and consequently groundwater resource potential carbonate rocks in Iran considering the role of the chief factors affecting karst water potential. Accordingly, 25 different data layers where interrogated in a GIS platform. Subjective karst map was developed on the basis of what is considered to be a proper combination of these factors. The most important parameters are categorized to three driving factors include chemical, physical, and hydrogeological factors. Thematic map of each parameter was prepared using geographic information system (GIS). Measuring the rate and weight of the maps was performed using analytical hierarchical process (AHP), respectively. The final output map showed different zones of groundwater prospective potential, which was divided into five grades. According to the results, of the total area of 174049 km2 of carbonate outcrops in Iran, 10.5 % belongs to grade 1 (very high degree), 15 % to grade 2 (high degree), 24.5 % to grade 3 (medium degree), 29 % to grade 4 (low degree), and 21 % grade 5 (very low degree) of karst water potential. There is a significant karst water source in the southwest, north, and north east of Iran. The highest grade is belonging to the Kopet-Dagh zone in northeast of Iran.