Predicting Large-Scale Landslide Initiation Based on the Local Field Factor of Safety: An Application to the Braies Catchment in Northern Italy

Landslides pose a significant hazard to citizens, infrastructures, especially in mountainous landscapes. The deterministic prediction of landslide susceptibility requires an incorporated approach between multiple disciplines such as geology, geomorphology, and hydrology. This study uses a hydromechanical framework aimed at predicting large scale shallow landslide initiation by calculating the local field factor of safety (LFS) as an indicator of slope instability. The framework integrates (1) a finite element method (FEM) solver for a coupled hydromechanical landslide model within a Java object-oriented modeling system, and (2) a third-party hydrologic model, enabling detailed multidimensional simulations of slope stability under transient rainfall conditions in large-scale hillslopes. The hydromechanical framework is validated through a benchmark test on a homogeneous, constant-slope hillslope and then are further applied to a large-scale real-world scenario in the Braies Alpine Catchment, Alto Adige, Northern Italy. The first application successfully predicted the triggering of a shallow landslide under sustained rainfall, while the second application accurately identified the initiation of multiple landslides during an intense summer storm. The results demonstrate the framework’s capability to predict landslide initiation with high precision, even in complex slope environments, providing a cost-effective tool for landslide risk assessment.