Numerical earthquake-induced landslide hazard assessment at regional scale in the Colombian Andes

Abstract

This paper presents an implementation of the SEM-Newmark analysis framework as a method for the earthquake-induced landslide hazard assessment at a regional scale. The implementation relies on a semi-coupling between ($i$) the physics-based numerical simulation of seismic wave propagation in the 3D domain through the Spectral Element Method (SEM) and ($ii$) the evaluation of seismic permanent displacements in spatial domains through the direct Newmark Method. The numerical solver was verified against analytical solutions and validated on the case study of the $M_{w}6.0$ Mesetas earthquake in the Colombian Andes, where hundreds of landslides were triggered. Results highlight the significance of incorporating topographic effects and demonstrate that the proposed framework provides a more accurate hazard assessment compared to traditional pseudo-static approaches. A basic probabilistic hazard zonation approach is introduced, linking landslide occurrence to permanent displacement thresholds, resembling the concept of a fragility curve. The SEM-Newmark analysis framework offers a robust alternative for seismic hazard evaluation in regions with complex topography, improving decision-making for earthquake-prone areas.