Assessing landslide susceptibility using geospatial technology in Bonga town, southwestern Ethiopia

Abstract

ABSTRACT This study aims to investigate the main factors that contribute to frequent landslides in Bonga town using GIS and remote sensing. To this end, a frequency ratio model in integration with geospatial technology was applied. The first input parameter (landslide inventory data) was collected and randomly categorized into training and validation. The second input parameters were causative landslide factors such as slope, aspect, curvature, elevation, land use, lithology, stream distance, and distance to the road. The contributing rates of landslide causative factors were calculated using the frequency ratio model based on causative factors and landslide training data. The study found that distance to the road, distance to the stream, elevation, and aspect were the most important factors for the occurrence of landslides in Bonga town. Land use and slope were the moderate contributing factors to landslide occurrence, while curvature and lithology were the least important contributing factors. The landslide susceptibility index map shows that the largest portion of the study area falls under the moderate (42.3%,) and high (34.3%) susceptibility zones. Hence, different intervention strategies for saving lives and assets should be developed swiftly based on the vulnerability level of each site.