National scale landslide susceptibility mapping in Ethiopia using multi criteria decision analysis with InSAR validation for disaster risk reduction and early warning
摘要
Ethiopia’s complex topography, intense seasonal rainfall, and active geological settings render it highly susceptible to landslides, particularly in highland regions above 2000 m. This study presents a comprehensive national-scale landslide susceptibility assessment integrating multiple geospatial datasets using the Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC) methodologies. Nine conditioning factors were systematically evaluated: slope gradient, precipitation, lithology, soil type, road proximity, land use/land cover, aspect, elevation, and historical landslide records. The susceptibility model classified Ethiopia’s terrain into five zones: very high (0.1%), high (8%), moderate (37%), low (44%), and very low (11%), indicating that approximately 45% of the national territory exhibits moderate to very high landslide probability. High-susceptibility zones predominantly occur in the Amhara, Oromia, Tigray, and Southern Ethiopian regions, and correlate with steep slopes (> 25°), intense rainfall (> 1,000 mm/yr), volcanoclastic lithology, and anthropogenic pressures, including deforestation and infrastructure development. Model validation employed 405 historical landslide inventory points, achieving 87% accuracy in high-susceptibility zone predictions, while Receiver Operating Characteristic (ROC) analysis yielded an Area Under Curve (AUC) of 0.87. Complementary Interferometric Synthetic Aperture Radar (InSAR) displacement analysis in selected high-risk areas (Dessie, Arba Minch-Gofa, Debre Berhan, and Jimma) corroborated susceptibility predictions through detected surface deformation patterns. These findings provide critical baseline information for Ethiopia’s Multi-hazard Impact-based Early Warning and Early Action System (2023–2030), supporting evidence-based decision-making for land use planning, infrastructure development, and climate adaptation strategies in vulnerable regions. By enabling risk-informed land-use planning, prioritization of slope-stability interventions, and targeting of early warning in high-exposure corridors, this framework directly supports the Sustainable Development Goals—especially SDG 11 (Sustainable Cities and Communities), SDG 13 (Climate Action), and SDG 9 (Resilient Infrastructure)—with co-benefits for SDG 1 (No Poverty), SDG 2 (Zero Hunger), SDG 3 (Good Health and Well-being), and SDG 15 (Life on Land).