Landslide Assessment and Hazard Zonation in the Birbir Mariam District, Gamo Highlands, Rift Valley Escarpment, Ethiopia

Abstract

The current research focused on landslide assessment and hazard zonation in the Birbir Mariam district of the Gamo highlands. The study examined landslide causative factors and used the slope susceptibility evaluation parameter to create a landslide hazard zonation covering an area of 110 km2. The landslide hazard zonation was classified using facet-wise observation. As a result, the intrinsic and external causal parameters of score schemes have been held responsible for slope instability. Inherent causative elements consist of slope geometry, slope material (rock/soil), structural discontinuities, land use/land cover, and groundwater conditions. Rainfall and human interest have seemed as external elements. The intrinsic and external triggering elements for every facet (a total of 106) were rated for their contribution to slope instability. Finally, an evaluated landslide hazard value was calculated and classified into three landslide hazard classes. According to the findings, the area has a high hazard zone of 18.87% (20.76 km2), a moderate hazard zone of 54.72% (60.19 km2), and a low hazard zone of 26.41% (29.05 km2).