Three-Dimensional Slope Stability Modeling of a Landslide-Prone Area in South Western Ghats, Kerala

Landslides, triggered by natural or anthropogenic factors like rainfall, earthquakes, and construction activities, are prevalent in the Western Ghats in the south and the Himalayas in the north of India. Most of the landslides in the Western Ghats are triggered by heavy rainfall during the monsoon. Despite many mitigations and slope stabilization measures, every monsoon season witness huge loss of human lives and property damage which demands further research studies. The current study focuses on Kavalappara, Malappuram district of Kerala, located on the windward slopes of the South Western Ghats. Following the 2019 landslide disaster, this region has been identified as prone to landslides. In this analysis, a Three-Dimensional (3D) slope stability analysis was conducted using Scoops3D, a software that assesses slope stability across digital landscapes using a 3D method of columns approach. A 1-Arc resolution Digital Elevation Model (DEM) obtained from USGS Earth Explorer, processed in ArcGIS Pro, served as the primary input for the model. The DEM used here along with additional topographic inputs makes the slope stability analysis more accurate. The results obtained show that as the pore pressure ratio (R_u) increases, the value of the Factor of Safety (FoS) decreases, indicating slope instability. Also, the higher R_u results in lower failure volumes, indicating shallow landslides. The study contributes toward planning of proper landslide mitigation measures and developing landslide early warning systems.