Understanding the Factors Contributing to Landslide Hazards in Sheko, Ethiopia

Abstract This study was conducted in Sheko District, Bench Sheko Zone, and Southwestern Ethiopia Regional State. The region has been experiencing recurrent landslide problems for several years. The primary objective of the study was to evaluate landslide hazard in the study area. To achieve this: the Slope Susceptibility Evaluation Parameter rating scheme was used. The parameters considered in this study included slope geometry, slope material, structural discontinuities, land-use and land-cover, groundwater depth, seismicity, rainfall, and human activities. In addition, an inventory of past landslides in the study area was prepared. Facet-wise observations were made thematic layers for past landslides, slope facets, and causative factors were created in a GIS environment using secondary data, field observations, topographical maps, and satellite images. Hazard index value was first calculated for each parameter class and ratings for each parameter class were assigned based on the prevailing conditions on individual facets. The results showed that the landslide hazard map produced by the Slope Susceptibility Evaluation Parameter approach categorized the study area into Very High hazard, High hazard, Moderate hazard, and Low hazard zones with areal coverage’s of 2.372 km², 48.198 km², 54.75 km², and 0.015 km², respectively. The LHZ map produced by the SSEP approach demonstrated approximately 100% validation with past landslide activities.