Landslide Susceptibility Analysis by Applying TRIGRS to a Reliable Geotechnical Slope Model

This paper presents the results of a research aimed at analysing the susceptibility to shallowlandslides of a study area in the Calabria region (Southern Italy). These shallow landslides, which insome cases evolve as debris flows, periodically affect the study area, causing damage to structuresand infrastructure. The involved soils come from the weathering of gneissic rocks and cover about60% of the study area. To fulfil the goal of the research, the Transient Rainfall Infiltration and GridbasedSlope-Stability (TRIGRS) model was first used, assuming input data (including physical andmechanical parameters of soils) provided by the scientific literature. Then, the preliminary resultsobtained were used to properly locate in situ investigations that included sampling. Geotechnicallaboratory tests allowed characterising the investigated soils, and related parameters were used asnew input data of the TRIGRS model. The generated shallow landslide susceptibility scenario showeda good predictive capability based on the adoption of a cutoff-independent performance technique.