Identification and mapping of Urban flood susceptibility in Lega Tafo using GIS-based multi-criteria decision making and remote sensing

Flooding is a natural disaster that causes both fatalities and economic damage in many regions of the world. For many years, Ethiopia has struggled with flooding, which has resulted in economic losses and significant hardship for the local community. This study aims to identify and map areas in Lega Tafo susceptible to flooding using GIS and remote sensing, combined with multi-criteria decision-making (MCDM) analysis. Six criteria-elevation, slope, rainfall, distance to rivers, land use, and soil types-were considered, based on expert opinions and a review of relevant literature. The weight of each criterion was determined using the Analytic Hierarchy Process (AHP), informed by the literature. Then, using ArcGIS, a weighted overlay analysis was carried out to combine all the factors and pinpoint places that are vulnerable to flooding. The results reveal four flood risk zones: high, moderate, low, and very low, covering 4145 hectares (41.1%), 2999 hectares (29.7%), 1751 hectares (17.4%), and 1191 hectares (11.8%), respectively. This indicates that 70.8 percent of the area falls under moderate to high flood risk. The Receiver Operator Characteristic (ROC) curve method validated the flood map. The findings of this study can help stakeholders and policymakers take appropriate measures to reduce flood risks and improve resilience in the region. Moreover, this study advances prior flood susceptibility research by integrating different data sources with AHP analysis, which enhances our understanding of flood risk assessments.