Slope Stability Analysis for Deterministic Shallow Landslide Assessment and Mapping: A Case Study in Kibawe, Bukidnon

Abstract

The slope’s stability in mountainous or hilly region is significantly important for the safety and protection of the people and the environment. Intensive field sampling was carried out in the study sites at Kibawe, Bukidnon, Philippines and soil samples were subjected to laboratory tests. The study applied the deterministic method through slope stability analysis to calculate the factor of safety (FOS) for landslide assessment. It also used Geographic Information System (GIS) particularly the ArcGIS software for FOS mapping. The results revealed that the study sites have mostly inorganic but highly expansive fine-grained soils. The values of the FOS varied in each steady-state condition. For fully-saturated and dry conditions, the values ranged from 1.54-9.98 and 1.94-12.66, respectively. For partially-saturated condition where m = 0.75, m = 0.5 and m = 0.25, the values of FOS ranged from 1.65-10.65; 1.74-11.32; and 1.84- 11.99, respectively. In general, the FOS values signified that the study area was stable against sliding; however, there was a considerable decrease in FOS values when the slope changed from completely dry to fully-saturated condition. The created set of FOS maps lay out a visual impression and the variation of slope stability condition in the study area. The findings provide a baseline reference study for the area’s slope stability that is essential in planning or further assessment of the study area. Furthermore, this can be directly used by the local government for land-use planning and future development.