Geospatial Modeling of Landslide Susceptibility in Debek, South Wollo, Ethiopia: Comparative Analysis of Frequency Ratio and Analytical Hierarchy Process Models for Geohazards Management

Degfie Teku ^* Alemnew Ali ^* Tesfaldet Sisay Bishaw Mihret

• College of Natural and Computational Science, Mekdela Amba University, Tulu Awuliya, Ethiopia

Landslides represent a significant geohazard in the northern Ethiopian highlands, causing extensive damage to farmland, infrastructure, and settlements, with severe socio-economic repercussions. Addressing the critical need for improved natural hazard management, this study investigates landslide susceptibility in Debek, South Wollo, Ethiopia, using advanced geospatial modeling techniques. The primary objectives are to identify and integrate key causative factors of landslides, evaluate the efficacy of Frequency Ratio (FR) and Analytical Hierarchy Process (AHP) models, and provide actionable insights for georisk mitigation. Field surveys and satellite imagery identified 328 landslide events, partitioned into training (75%) and validation (25%) datasets. Eight critical landslide-influencing factors-slope gradient, aspect, elevation, proximity to streams and springs, slope material, distance to lineaments, and land use/land cover (LULC) were systematically analyzed. Among these, slope material and distance to springs were identified as the most significant contributors to landslide susceptibility. Landslide susceptibility map's were developed using FR and AHP models, with validation conducted through landslide density indices (R-index) and receiver operating characteristic (ROC) curves. Results demonstrated a high degree of concordance between highly susceptible areas and observed landslide events. The FR model exhibited marginally superior performance, achieving an ROC success rate of 0.828 and a prediction rate of 0.835, compared to the AHP model's ROC success rate of 0.826 and prediction rate of 0.832. The novelty of the study lays in the comparative analysis of Frequency Ratio (FR) and Analytical Hierarchy Process (AHP) models for landslide susceptibility mapping in a data-scarce region. These findings underscore the utility of GIS-based geomatics approaches in delineating landslide-prone zones, highlighting both the strengths and limitations of each model. This study provides critical resources for policymakers and stakeholders, supporting informed land-use planning, targeted geohazard mitigation, and comprehensive disaster prevention initiatives. By advancing the understanding of landslide dynamics in the Ethiopian highlands, this research reinforces the pivotal role of geospatial modeling in enhancing natural hazard management and susceptibility reduction frameworks.