Landslide disasters triggered by extreme rainfall events: the case of Montescaglioso (Basilicata, southern Italy).

We present the results of the study of a large and rapid landslide disaster event, which occurred in Montescaglioso, southern Italy, on 3 December 2013. The studied landslide developed following extreme rainfalls in a zone characterized by a stabilized paleo-landslide body and anthropized in time, filling some streams of the original hydrographic network. The morpho-topographic setting characterizing the slope before the new landslide, has showed, in fact, a substantial stability confirmed also by the application of SINMAP (Stability Index MAPping) analysis. Nevertheless, heavy rains and floods caused a powerful and spectacular landslide event because of the anthropic removal of the old drainage network, which has caused the heaviness of the slope located upstream of the 20 collapsed buildings and along the ill-drained quick-road, built transversely to the slope.