Catalogue of Rainfall Events with Shallow Landslides and New Rainfall Thresholds in Italy

In Italy, rainfall-induced shallow landslides are frequent and harmful phenomena. The prediction of their occurrence is of social significance for civil protection purposes. For the operational prediction of rainfall-induced shallow landslides empirical rainfall thresholds based on the statistical analysis of past rainfall conditions that triggered slope failures are commonly used. The paper describes a catalogue of 1981 rainfall events, which caused 2408 shallow landslides in Italy in the period 1996–2012. Information on rainfall-induced landslides was collected searching chiefly online newspaper archives, blogs, and fire brigade reports. For each documented failure, we reconstructed the triggering rainfall conditions (rainfall duration D and cumulated rainfall E) using national and regional rain gauge networks. We analysed the rainfall conditions to determine new ED rainfall thresholds for Italy. The calculated thresholds can be implemented in a landslide forecasting system to mitigate landslide hazard and risk.