A novel physically-based methodology for assessing landslide susceptibility at large scales

Landslide susceptibility is the likelihood of a landslide occurring in a given area based on local terrain conditions (Brabb, 1984). It is fundamental for land-use planning and risk mitigation strategies and can be assessed through various approaches, including statistical and physically-based methods (Guzzetti et al., 1999; Reichenbach et al., 2018). Statistical approaches are preferred for small scale zoning as they rely on landslide inventories and thematic maps that are easier to gather, while physically-based methods remain challenging as they demand detailed geomechanical and hydrological inputs that are time-consuming and costly to acquire.

This study presents a novel physically-based methodology for large-scale landslide susceptibility assessment that integrates the limit equilibrium method (Borselli, 2023) with spatialisation criteria and statistical classification approaches (Mevoli et al., 2026). The procedure enables the generation of spatially distributed safety factor and failure surface depth maps, and susceptibility zoning. The methodology was applied to a ~40 km² area in Southern Italy, testing multiple scenarios to evaluate the influence of different geomechanical and hydraulic configurations. Model performance was assessed through a classification algorithm, revealing scenarios with optimal discrimination capability. The physically-based results were compared with those obtained from statistical approach, demonstrating the promising applicability of the proposed physically-based methodology for assessing landslide susceptibility at large scales.

This reproducible and adaptable framework offers a physically-based alternative for assessing ladslide susceptibility at large scales, proividing direct applications for landslide susceptibility zoning in research and operational contexts.

 

References

Borselli L. (2023). "SSAP 5.2 - slope stability analysis program". Manuale di riferimento. Del codice ssap versione 5.2. Researchgate.  https://dx.doi.org/10.13140/RG.2.2.19931.03361

Brabb, E.E., 1984. Innovative approaches to landslide hazard and risk mapping. In: Proceedings 4th International Symposium on Landslides, vol. 1, Toronto, pp. 307–324.

Guzzetti, F., Carrara, A., Cardinali, M., & Reichenbach, P. (1999). Landslide hazard evaluation: a review of current techniques and their application in a multi-scale study, Central Italy. Geomorphology, 31(1-4), 181-216. https://doi.org/10.1016/S0169-555X(99)00078-1

Mevoli, F. A., Borselli, L., Santangelo, M., Monte, N., de Lucia, D., Ugenti, A., & Rossi, M. (2026). Landslide susceptibility zoning through physically-based limit equilibrium method modelling. CATENA, 263, 109726. https://doi.org/10.1016/j.catena.2025.109726

Reichenbach, P., Galli, M., Cardinali, M., Guzzetti, F., & Ardizzone, F. (2005). Geomorphological mapping to assess landslide risk: Concepts, methods and applications in the Umbria region of central Italy. Landslide hazard and risk, 429-468.