Comparison of AHP and fuzzy AHP models for prioritization of watersheds

Prioritization of watersheds for conservation measures is essential for a variety of functions, such as flood control projects for which determining areas of top priority is a managerial decision that should be based on physical, social, and economic characteristic of the region of interest and the outcome of past operations. The objective of this study therefore was to investigate morphological characteristics and identify critical sub-watersheds which are liable to be damaged, using remote sensing/geographical information systems and multi-criteria decision-making methods AHP/FAHP. Fourteen morphometric parameters were selected to prioritize sub-watersheds using an analytical hierarchical process (AHP) and a fuzzy analytical hierarchical process (FAHP). Based on the FAHP approach, sub-watersheds, as vulnerable zones, were categorized in five priority levels (very high, high, medium, low, and very low levels). The conservation and management measures are essential in the high to very high levels categories. Thus, the FAHP approach is a practical and convenient method to show potential zones in order to implement effective management strategies, especially in areas where data availability is low and soil diversity is high. Finally, without having to encounter high cost and a waste of time, sub-watersheds can be categorized using morphometric parameters for implementing conservational measures to simultaneously conserve soil and the environment.