Reconstruction of scenarios of actual and future probability of occurrence to shallow landslides in a prone area of Northern Italy

Rainfall-induced shallow landslides affect buildings, roads, facilities, cultivations, provoking significant damages to people, economy and territory. The change in climatic conditions may impact the temporal probability of occurrence of these phenomena in a particular territory, in terms of both number of events per year and volumes of mobilized materials in a particular triggering event. For these reasons, it becomes fundamental the application of methodologies able to predict scenarios of temporal occurrence of shallow failures according to forecasted trends of the triggering parameters. In this framework, this work investigates the possible modification of the temporal probability of occurrence of shallow landslides in a prone area, passing from the actual climatic conditions to the projected climatic changes up to 2070. This approach was applied in Oltrepò Pavese (northern Italian Apennines), where several triggering events occurred since 2009. Temporal probability of occurrence was estimated applying a data-driven method based on rainfall and soil water content conditions at daily resolution, allowing to predict the possibility that shallow landslides could occur in a particular day. This model was applied using actual climatic conditions, since the use of field meteorological data of last 20 years, and projected future climatic conditions up to 2070, derived from climatic projections available in the study area. The results of this work allow to estimate the future changes in the probability of occurrence of shallow failures in this area than the actual conditions, both at yearly and seasonal scales, furnishing an important tool for the implementation of solution to reduce the future risk and to make effective land planning strategies. This work is part of the project NODES which has received funding from the MUR – M4C2 1.5 of PNRR funded by the European Union - NextGenerationEU (Grant agreement no. ECS00000036).