An Assessment of the Potential of Underground Dam Construction Using the AHP Fuzzy Methods in the Kouhdasht Plain

Aquifers management is of utmost importance used for supplying the water use in different sectors in the arid and semiarid regions. This research aims to evaluate the quality of groundwater resources and to find suitable locations for the construction of underground dams in the Kouhdasht area (west of the Lorestan Province). To evaluate the water quality for drinking and agricultural purposes, the chemical parameters of groundwater resources were placed in the Schaller and Wilcox diagrams. The results indicated that groundwater quality is desirable for various uses. To identify suitable locations for the construction of underground dams, factors namely: slope, lithology, land use, drainage network density, precipitation, temperature, distances from the village, well, fault, and springs were used. After providing the various data layers, the map of each factor is standardized and weighed using the fuzzy logic and the hierarchical analysis process, respectively. Evaluation of various factors influencing the determination of suitable areas for construction of underground dam revealed that three factors namely drainage network, lithology, and topographic slope with a weight of 0.243, 0.206, and 0.153, respectively, had the greatest impact on the selection of optimal locations. By overlaying the weighted maps provided for each layer in the Arc GIS 10, a map showing the suitable sites for construction of underground dams was produced. Based on the results, 20.35, 15.90, 14.92, 26.28, and 22.54 percent age of the area were evaluated as highly inappropriate, inappropriate, moderately, appropriate, and very appropriate for construction of underground dams, respectively. Performing detailed field surveys in the very appropriate areas, six sites were selected for construction of underground dams. These were located on the path of the fourth-order and greater streams.