Application of Fuzzy Spatial Multi Criteria Decision Making Approach in Determination of the Flood Vulnerable Zones (Case Study: Tehran Urban Basin)

Prioritization of the existent sub-basins in a basin in order to study flood control can be discussed in the framework of a spatial multiple criteria problem. In this research a Fuzzy planning support system based on spatial analysis using the multi criteria decision making methods of Analytic Hierarchy Process (AHP) and TOPSIS in Fuzzy environment to consider some uncertainty in decision making process is used. The AHP method is used to determine the structure of decision making process and to estimate the weights of criteria maps and the TOPSIS model is used to rank the sub-basins of Tehran urban basin. Also in order to perform spatial analysis for decision-making process, a developed toolbox in software environment with programming in visual basic is used. In this research a model is represented in which some vague concepts such as weights of decision making criteria are expressed in the form of linguistic variables to be converted to triangular fuzzy numbers. Finally, the sensitivity of the model was analyzed by changing the weights of decision making criteria and providing ranking scenarios. The results of sensitivity analysis showed that the sub-basin 3 acquired the first priority among the 19 scenarios for urban flood control study.