Prioritizing Suitable Location of the Underground Dam Construction UsingAHP in Kajbid-Balaqly Watershed Garmeh city

In this research, by integrating the GIS and the decision support system, the most suitable areas for underground dam construction were identified. This support system in three stages was used for Kajbid-Balaqly watershed in Garm, North Khorasan Province. In the first stage, the areas with potential for underground dam construction were identified by removing inappropriate criteria including class 1 and 2 waterways, slopes above 6%, geology including (Qt1), land use including residential areas, faults, qanats, wells and fountains. In the second step, 10 axes were chosen based on the highest level of the reservoir. In the third step, the process of AHP was used to evaluate and prioritize these 10 axes. For this purpose, four main criteria, namely water status including quantity with weight of 0.8 and quality with weight of 0.2, reservoir characteristics including permeability with weight of 0.53 and slope with weight of 0.24, depth with weight of 0.12 and surface with weight of 0.10, axial characteristics including depth with weight of 0.75 and length with weight of 0.17 and support with weight of 0.07, socio-economic factors including water requirements with weight of 0.8 and access with weight of 0.2 were used. The results showed that the best axis for underground dam construction is alluvial deposits river bed of the basin's output.