An integrated approach to identify flood hazard and risk areas in Melka Soda district, Southern Ethiopia

Abstract

Flooding is a severe meteorological event that can result in fatalities and major economic losses. This study utilizes geographic information system, remote sensing technology, and multi-criteria decision making to create an accurate flood susceptibility map for the Melka Soda district in Southern Ethiopia. Various factors such as normalized difference vegetation index, landuse landcover, soil type, drainage density, slope, rainfall, geology, and elevation were taken into consideration when mapping out areas susceptible to flooding. The results indicate that 7.1%, 16.6%, 20%, 29.9%, and 26.4% of the district are classified as very low, low, moderate, high, and very high hazard zones, respectively. By analyzing population density and land use in conjunction with the flood hazard map, five zones of varying risk levels were identified: very low, low, moderate, high, and very high-risk zones covering 12.4%, 29.5%, 39%, 10.6%, and 7.5% of the district respectively. This showed that 18.1% of the district is classified as having a high to very high level of flood risk. To validate this result, survey data was used to map 28 flood points in the area, and a receiver operating characteristic curve was plotted, resulting in an area under the curve of 86.7%. This confirms the accuracy of the proposed framework, which can assist authorities in creating development policies that consider the current flood risk in the area.