GIS-BASED AHP-OWA APPROACH FOR LOCATING SUITABLE SITES FOR WATER HARVESTING DAM IN QASSIM REGION, SAUDI ARABIA

Selection of a water harvesting dam site involves a complex array of decision criteria that may have conflicting values. Finding the optimum location requires integration of the capacities of Geographic Information Systems (GIS) and Multi-criteria Decision- Making (MCDM). In this paper, a GIS-based multi-criteria decision analysis approach is used to solve this problem. The approach is based on the extension of Analytical Hierarchy Process using fuzzy quantifiers-guided Ordered Weighted Averaging operators (GIS-based AHP-OWA). This approach is applied to determine the optimal site of a water harvest dam in Qassim region, Saudi Arabia. Several factors affect the selection of the best location of the target water harvesting dam such as: slope, landuse, soil type, geology, rainfall, drainage network, distance from the road, and distance from the cities, are used. The results showed that using a combination of GIS-based AHP–OWA is proper approach for optimal water harvesting site selection, where this approach provides a generic powerful decision-making tool that allows decision-makers to define a decision strategy on a continuum between pessimistic (risk-averse) and optimistic (risk-taking) strategies.