Evaluating flood risk management practices and vulnerability mapping in Alawuha watershed (North Wollo Zone, Ethiopia) using GIS and remote sensing

The current magnitude of flooding in Ethiopia is unprecedented. It is a typical disaster in Ethiopia with the evidence of the recent Dire Dawa and Omo River surroundings, especially during the rainy season. The situation resulted in much human death and destruction of infrastructures in different parts of the country, and the Alawuha watershed is among the typical areas for this problem. The study’s aim was to evaluate the flood risk management practices and map flood-vulnerable areas in the Alawuha catchment. Geographic information system (GIS) multi-criteria analysis and remote sensing with field verification were employed to meet the objective of this study. Slope, elevation, rainfall, drainage density, soil type, and distance to rivers are flood event aggravating factors in this study. These factors were weighted accordingly with their contribution to flood hazards. In addition, land use/land cover (LULC) and population distribution were identified as flood vulnerability factors. The weighted overlay analysis result shows that Sanka, Afrikari, Gedo-ber, Hara, and the surroundings, Woldia, were identified as high flood risk areas of the watershed. To minimize this problem, applying physical and biological measures at the watershed level is recommended.