Susceptibility analysis to identify the zones potentially exposed to rapid flowslide risk

Rapid landslides are one of the most significant natural hazards and the cause of important losses of human lives and material damages worldwide. In order to achieve an efficient protection from these disasters, a full knowledge about the propagation phase, once the landslide has started, is necessary. Landslide susceptibility analysis allows to assess volume (or area) and spatial distribution of landslides which exist or potentially may occur in an area. The aim of this PhD thesis has been to perform a landslide susceptibility analysis on an area in the Province of Reggio Calabria, regularly and historically involved by flow-like landslide events. The susceptibility analysis has allowed drawing the susceptibility maps of the area, where the hypothetical areas involved by rapid flowslides has been drafted. Laboratory tests have been performed to obtain the rheological law that controls the soil-water mixtures behaviour involved by the flowslides and numerical back-analyses have been carried out on past flowslides occurred in the area in order to validate the rheological law. A numerical code has been used to simulate the propagation phase of the hypothetical trigger zones, previously identified, changing a lot of parameters. Several susceptibility maps have been obtained and the hypothetical zones at risk have been delimited. Moreover, the evaluation of potential impact forces caused by flowslides, which are useful for the design of passive structural mitigation measures, has been performed.