Site Selection for Constructing Underground Dams Using Boolean Logic and the AHP method in the Imamzadeh Jafar Gachsaran Watershed

Underground dam is an important hydraulic structure in management water in the arid and semi-arid areas. The aim of this research was to identify appropriate sites for constructing underground dams, where they do not limit construction of other such dams in this region. By benefiting from the Boolean logic, and using the physiographic, topographic, geological, land-use, fault, and aqueduct criteria, the regions that had no limitations for the constructing underground dams were selected. Using the analytical hierarchy process as well as the quantity and quality criteria of water, economic and social, dam reservoir, capacity and land-use, suitable sites for project construction underground dams were prioritized. The inconsistency rate in this research was 0.05. Investigation of the inconsistency rate indicated that the scoring performed for the criteria and sub-criteria studied here were acceptable. The results of prioritization of the region indicated that the watershed slope was the most important criterion in determining suitable site for such projects, thus constructing dams at steep slopes was not economical. Furthermore, given the geological conditions of the region and high score of this criterion in constructing underground dams, this criterion should be paid more attention to in such constructions. Overall, the results indicated that the regions located in the western and central parts of the watershed had a higher score for underground dam construction. Considering the importance of underground dam in dry and semidry regions, it can be stated that by constructing such dams in these regions, it is possible to improve the management of water resources.