Efficiency assessment of the environmental variables in the Qanat systems based on major hydrological basins in Iran

Abstract

Qanat system, as a great human heritage, contributes to the sustainable management of groundwater in the arid and semiarid regions of the world. The main aim of this paper was to efficiency assessment of the environmental variables in the construction of the Qanat system in Iran. Using the geographical information system (GIS) and statistical method of receiver operation characteristic (ROC), the efficiency of 20 environmental variables was assessed based on divisions of 30 major hydrological basins. Results revealed that most physical parameters and anthropogenic characteristics have significant effects on the construction of Qanat water lines with an AUC index > 0.6. The Pearson correlation test also confirmed the positive and significant relationships between the Qanat system and mentioned environmental parameters. From a geological viewpoint, the results highlighted the effective role of Quaternary aged alluvial sediments with very high permeability and low density of crust rocks in arid soils of arid and semiarid regions, such as playa fields in NamakTehran, Kavir, Lut, and Siahkuh basins. Regarding the spatial expansion of the Qanat system in Iran, the higher effects of some test variables, such as the climatic element of temperature, fault density, and drainage density, were rejected due to poor discrimination values of the AUC index < 0.6.