Landslide assessment and susceptibility zonation in Ebantu district of Oromia region, western Ethiopia

Abstract

The present paper deals with landslide hazards in the Ebantu district of the Oromia regional state of western Ethiopia. Ninety-two landslides were recorded during field investigations and Google Earth interpretation. The data sets were prepared as a layer in the spatial GIS database that was later utilized for generating the landslide susceptibility zonation map. Slope, elevation, and distance from drainage were extracted from the digital elevation model, the geology is modified from the geological map of Nekemte, and the land use map was prepared from Landsat +ETM satellite (2015) using digital image processing techniques. The statistical index method was applied to identify landslide hazard areas, and statistical analysis was carried out based on the relationship between past landslides and the causative factors. The causative factor map is further classified into a number of classes based on their relative influence on mass movement and rating values are assigned to each class depending on their influence on slope instability. Based on their assigned weight values, the map overlay process is performed using Arc GIS 10.3, and finally, the landslide hazard map showing various zones is produced by the overlay technique.