Selection of Suitable Sites for Water Resources Provision by Constructing Underground Dam (Case Study: Southwestern Basin of Haj Aligholi Desert)

Background and Objectives: Considering that most regions of Iran have a hot and dry climate and the temporal and spatial distribution of rainfall in different parts of it is inappropriate, it is necessary to provide water resources in any part of the country by managing surface and groundwater resources. One of the suitable methods of providing small water sources in hot and dry areas is the use of underground dams. The purpose of this research is to provide water for livestock through locating and constructing underground dams, especially in dry areas. The studied area is the basin located in the southwest of Haj Aligholi desert of Damghan, which also includes livestock passage.
Materials and Methods: For this purpose, the effective parameters for locating the underground dam including: stream network, slope, geology, fault, well, spring, qanat and livestock passage were determined. Layers of information and necessary boundaries were prepared based on the characteristics of the region and similar researches in the ArcGIS software environment, and then the integration of the final maps was done using Boolean logic and geometric average methods, and the areas prone to water supply for livestock was determined in a part of this desert watershed.
Results: Findings of this research indicate the very appropriate performance of geometric average method in positioning because the use of logistic function in this method and elimination of expert opinions for weighting lead to the reduction of possible errors. Comparison of the integrated maps by these two methods is evident in the ranking of suitable areas. Based on the results, the axis no. 6 in both methods has become the most appropriate axis in construction of the underground dam. In general, results show the high accuracy and less error of the geometric average method compared to the results of the Boolean logic method.
Conclusion: Based on the results of this research, it is possible to prioritize the proposed options in the final map for locating of the underground dam by conducting field visits and studies and considering other factors such as water demands of the region and social and environmental impacts. Considering the prevailing conditions in hot and dry regions, as well as the advantages of underground dams, few and negligible disadvantages, short construction time and low maintenance cost, it is suggested to use this structure to manage and supply water resources in these regions.