Suitable Site Selecting of The Underground Dam Construction for WaterResources Management in Arid and Semi-Arid Lands

Site selection is the first and most important stage in implementation of natural resources management projects. It can be effective in reducing the cost and timing of projects. The underground dam is one of the structures that reservoir is created in the underground, and its extraction depends on the topography and geology conditions of the area, so its location is very important from the hydrological, economic, and social points of view. In this research, the ARAS multi-criteria decision-making model and geographic information system (GIS) were used to select the most suitable sites for the underground dam construction in Kajbid-Balaghli Watershed, Garmah, North Khorasan. First, suitable sites were determined by using an exclusion method based on criteria (stream order, slope, geology, land use, fault, qanat, and spring). To prioritize suitable locations, water quantity criteria, water quality, reservoir slope, reservoir permeability, reservoir depth, reservoir surface, structural height, structural length, anchorage, water requirement, and access to the structures were used to determine the appropriate locations. The relative importance of the criteria was done using AHP method. Finally, the ARAS decision method was used to prioritize the suitable sites. Results showed that the water quantity criterion with relative importance of 0.23 and the criterion of underground dam anchorage with the relative importance of 0.02 gain highest and lowest score in views of the experts, respectively. The most suitable sites for the construction of underground dam was location A with Si = 0.36 and Ki = 1.