A 3D Shallow Translational Landslide Susceptibility Model Accounting for Side Resistance and Vegetation Roots

Uniform rainfall infiltration and infinite slope stability models are computationally efficient for large-scale landslide susceptibility mapping but overlook three-dimensional (3D) effects from complex topography, side resistance, and spatial-temporal variability in rainfall and soil properties. While 3D limit equilibrium models address these issues, they are computationally intensive over large regions. This study introduces a Three-Dimensional Translational Slide (3DTS) model for simulating rainfall-induced shallow landslides. The 3DTS model integrates the generalized Green-Ampt infiltration approach for non-uniform rainfall with a corrected 3D Janbu method that accounts for side resistance and vegetation root reinforcement. Each digital elevation model (DEM) cell is treated as a soil column, aggregated to form slip surfaces. Validation against 3D Bishop and finite element methods demonstrates the model’s accuracy and efficiency. A case study of landslides in 2011 at Kvam, Norway, investigates the influence of slip surface geometry, rainfall conditions, side resistance, and vegetation roots on landslide prediction. • Developed a physically-based 3D slope stability model that can account for side resistance and vegetation root reinforcement for shallow landslides • Developed a model simulate a non-uniform rainfall history to compute transient infiltration analysis efficiently • Simple and optimized approaches for generating 3D slip surfaces efficiently • Highly efficient model capable of analyzing 3.5 times the existing 3D slope models for a regional scale, whilst maintaining similar performance • Recommends the appropriate 3D slip surface for forward analysis of slope stability