Landslide susceptibility assessment in Sabah, Malaysia: A bivariate frequency ratio approach

Abstract

A statistical bivariate model, frequency ratio, was used to assess the susceptibility of Pekan Nabalu to Kundasang area to landslides, using a geographic information system as a tool because the number of reported landslide cases rises annually. A total of 564 landslides (0.27 km2) were detected from field observations, Google Earth satellite imagery, and IFSAR imagery, creating a landslide inventory map (dependent factor). To determine landslide susceptibility, eight landslide causative factor maps (independent factor) were considered: slope angle, slope aspect, slope curvature, drainage proximity, lineament proximity, lithology, land use, and soil series. The integration of these dependent and independent factors resulted in a regional-scale spatial landslide susceptibility analysis (LSA) map with five susceptibility classes. Approximately 11.39% (12.99 km2), 25.56% (29.14 km2), 29.67% (33.82 km2), 23.6% (26.9 km2), and 9.78% (11.15 km2) are classified as very low, low, moderate, high, and very high susceptibility classes, respectively. Using the area under the curve validation method, the prediction and success rates were 82.63% and 82.6%, respectively. The LSA map is considered reliable because 239 landslides (0.14 km2) were classified as high to very high susceptibility classes. Therefore, this study provides valuable insights for stakeholders, researchers, and professionals, facilitating the proposal of suitable mitigation measures and the development of robust landslide management plans.

Quantitative Landslide Hazard Assessment Using Frequency Ratio Model: A Case Study from SMK Kundasang, Sabah, Malaysia

“…The elements of distance from lineament, drainage and road agree on the significance of 0 m to 50 m intervals contributing to the highest Frequency Ratio value. This is justified by Arbanas and Dugonjic [30] and Roslee and Krishnan [20]. More landslide occurrence can be observed closer to lineament, drainage and road.…”

“…This is attributed to the fact that drainage has the potential to induce erosion and saturate the lower portion of a slope [19]. The possibility of a landslide to occur also significantly elevates as the distance from the road decreases [20]. Landslide scars were spotted, whether treated or not, along the main and minor roads in the study area.…”