GIS-Based Landslide Susceptibility Assessment of the Upper Marikina River Basin Protected Landscape, Rizal Province, Philippines, using Analytic Hierarchy Process

The Upper Marikina River Basin Protected Landscape (UMRBPL) suffers significant consequences from landslides, including fatalities, property damage, and environmental degradation. This study was conducted to assess the landslide susceptibility of UMRBPL using Analytic Hierarchy Process (AHP). The analysis identified that slope had the highest contribution to landslide with 28.04%, followed by land use and land cover (20.50%), average annual rainfall (20.08%), soil morphology (8.46%), typhoon frequency (8.08%), distance to lineament (7.74%), and soil geology (7.10%). Based on the landslide susceptibility, 1.80% with very high susceptibility, 46.39% of the area were classified as highly susceptible, 38.05% with moderately susceptible, 12.76% with low susceptibility, and only 1.00% with very low susceptibility. Validation of the susceptibility assessment through Area Under the Curve (AUC) analysis yielded a score of 0.87. Insights from AHP can facilitate informed decision-making for implementing mitigation strategies, such as slope stabilization and land use regulations. This study emphasizes the urgent need for proactive measures to safeguard vulnerable landscapes like UMRBPL from the devastating impacts of landslides.