<![CDATA[Landslides are among the most significant natural disasters in Indonesia, and the Beji Sub-watershed in Pulung District, Ponorogo Regency, is identified as a hazard-prone area with a history of major landslides in 2017. This study aims to assess landslide hazard levels in the Beji Sub-watershed using a fuzzy logic method based on two parameters: slope gradient (40% weight) and landslide density derived from Kernel Density analysis (60% weight). Both parameters were fuzzified using linear membership functions and subsequently combined via Fuzzy Overlay using Gamma (γ = 0.975) and Product operators in ArcGIS 10.4.1. Pixel correlation analysis revealed a weak-to-moderate negative relationship between slope gradient and landslide density (r = -0.29), indicating that the two parameters are complementary rather than mutually reinforcing. Validation against 32 historical landslide points demonstrated the superiority of the map produced by the Gamma operator, with 90.6% of events concentrated in the High to Very High hazard classes, compared to only 59.4% for the Product operator map. Analysis of soil physical properties at 12 sample points reinforced this spatial pattern: the eastern region, characterised by clay texture, low permeability (7.41 cm/hour), and moderate Soil expansivity potential, supports the high-hazard classification, whereas the western region, characterised by sandy loam texture and high permeability (28.32 cm/hour), exhibits a more varied hazard pattern across gentle and steep zones. This study confirms that the Gamma operator provides a more representative approach for landslide hazard mapping in the Beji Sub-watershed and can serve as a basis for disaster mitigation recommendations]]>
Copyrights © 2026
