Flood risk zonation using a multi-criteria spatial group fuzzy-ahp decision making and fuzzy overlay analysis

Abstract

In this study, a GIS based approach has been proposed for the flood risk zonation based on a multi-criteria spatial group fuzzy AHP decision making analysis and its integration with fuzzy overlay analysis. For this purpose, 10 layers affecting flood occurrence have been used including: the Digital Elevation Model (DEM), Slope, NDVI, Flow Accumulation (Flow Ac.), HOFD, VOFD, Topographic Position Index (TPI), Topographic Wetness Index (TWI), Curve Number (CN), Modified Fournier Index. Each layer was classified into 5 sub-classes and their preference at its layer was weighted by a group of experts using fuzzy analytical hierarchy processes (GFAHP) method. Finally, the risk map of the studied area with the weight of experts and fuzzy overlay method was product and divided into five categories.