Urban flood vulnerability mapping using integral value ranked fuzzy AHP and GIS
A Atijosan, Ibrahim Isa, Alaga Abayomi
Abstract
An integral value ranked fuzzy analytical hierarchy process (AHP) and geographic information system (GIS)-based multi-criteria decision-making (MCDM) system for urban flood vulnerability mapping of Ile-Ife is presented. Elevation, slope, soil, rainfall, drainage density, geology and land use land cover information were used as input to the fuzzy-AHP MCDM system. The integral value method was used in prioritising and assigning weights to each input in the MCDM process due to its ability to represent the relative importance of two or more triangular fuzzy numbers (TFNs). Vulnerability maps were created using GIS techniques based on the aggregation of the input factor and their derived weights in the fuzzy AHP MCDM system. Validation of the methodology was carried out by simulating flooding across the study area. The flood vulnerability maps will help identify vulnerable areas and provide needed information to help mitigate the disaster risk posed by floods.