Rapid Landslide Analysis in an Alpine Watershed: A Case Study of the Rio Fenils (NW Italy)

This study, developed within the framework of the “Rapid landslide risk mitigation: design for sustainability criteria in mountain areas” (RaRiskD) – PRIN 2022 program (D.D. 104 - 02/02/2022 Ministero dell’Università e della Ricerca – CUP E53C24002910006), investigates rapid landslide processes affecting the Rio Inferno watershed, in the vicinity of the former Chaberton Military Road (Cesana Torinese, Western Alps, Italy). Repeated debris flow events have severely damaged the historical road, leading to its permanent closure to traffic. The research integrates geological, geomorphological, and historical analyses to evaluate the local susceptibility to rapid landslides using the DfPI methodology. A high-resolution digital terrain model was produced through UAV photogrammetry, providing the basis for detailed geomorphological interpretation and numerical simulations. Rainfall data from nearby monitoring stations were processed to identify critical precipitation thresholds responsible for triggering debris flow events. The HEC-RAS code was employed to simulate propagation scenarios under varying rainfall conditions and return periods. The outcomes highlight the dynamic behavior and destructive potential of these mass movements, stressing the need for improved hazard assessment and mitigation measures. The approach demonstrates how the integration of remote sensing, rainfall analysis, and numerical modeling can effectively support the design of protective structures and risk management strategies in alpine environments, particularly under the evolving impacts of climate change.