Assessment of urban vulnerability to flood risk by using GIS-based Best-Worst method

As urban population growth continues and climate change increases, it is predicted that more people will be exposed to climate change events, including floods, in the coming years. Floods are one of the most catastrophic natural disasters that can damage natural infrastructure and ecosystems and affect the lives of millions of people around the world. In this study, to assess the vulnerability of districts 1 in Shiraz to flood risk, a multi-criteria decision-making method based on Geographic Information System (GIS) was used. The criteria used in this study include land use, population density, worn-out texture, slope, waterway network and distance from the bridge Also, the best-worst (WLC) method has been determined to combine the standard maps and produce their initial weight. According to the author, so far no study has used the WLC method to assess urban vulnerability to flood risk. The weight obtained for the criteria shows that the population density factor and the waterway network with 0.453 and 0.041 have the highest and lowest standard weights in preparing a vulnerability map, respectively. The results of the best-worst method with a compatibility rate of 0.07 show that the criteria comparisons are more compatible and stable. In general, the results show that in the northern and northeastern parts of the study area, due to high population density and density of residential tissue, soil permeability levels have decreased and runoff volume has increased. Therefore, in these areas, the potential for flood risk is higher than in other areas.