Flood Hazards Mapping by Linking CF, AHP, and Fuzzy Logic Techniques in Urban Areas

Abstract

Flooding has become a devastating natural hazard worldwide, posing a substantial hazard to civilization and leading to socioeconomic losses. Urban flooding in India is on the rise due to unplanned urbanization, uncontrolled population growth, and changes in land use. For this analysis, the urban region of Dhanera (Gujarat state, India) has been chosen as a study area to prepare a flood hazard map in a geographic information system (GIS) environment using a multiple-criteria decision making (MCDM) technique. This study includes qualitative analysis compound factor (CF) and analytical hierarchy process (AHP), and quantitative analysis (fuzzy logic) using eight flood-affected criteria (slope, distance from the main river, land-use land cover (LULC), soil, drainage density, elevation, geomorphology, and proximity to stream confluence). MCDM techniques examined the weight of each criterion. The historical flood depth data have been collected via field visits or published articles for validation. Flood hazard maps have been classified into very high, high, moderate, low, and very low hazard zones. In each MCDM method, Ward 1 and Ward 2 are very highly and highly hazardous, respectively. The flood hazard map using fuzzy logic and inundation map matches very high, high, and very low categories. So, fuzzy logic is the best method to quantify flood hazards for Dhanera. This study provides a low-cost and time-efficient tool that assists local administration in prioritizing the preservation and control of floods, further helping the decision makers in mitigation planning to reduce damages.