Rainfall events able to trigger shallow landslides in Calabria (Southern Italy)

The key role of rainfall in landslides activation is highlighted by the increasing number of studies on rainfall triggering thresholds for shallow landslides over the last decades. Such thresholds are generally defined in terms of cumulated rainfalls in a period preceding the mobilization itself (TERRANOVA et al., 2007). Many areas of the Mediterranean basin are recurrently subject to catastrophic geo-hydrological events with high economic and social impact. In Calabria, an active tectonic region characterised by small basins with steep slopes, rainfall-induced slope movements frequently cause dramatic consequences to the environment and to population. Proper understanding and forecasting of rainfall events is a prerequisite for the adoption of appropriate mitigation measures and for reducing the risk. Aiming at characterising the rainfall events able to trigger shallow landslides in Calabria, the temporal structure of 152,575 rainfall events characterised by different durations has been analysed by applying the approach proposed by TERRANOVA & IAQUINTA (2011). Considered events were recorded between 1989 and 2008 at 155 rain gauges, at time steps of five minutes