TXT-tool 4.039-1.1 Definition and Use of Empirical Rainfall Thresholds for Possible Landslide Occurrence

In Italy, landslides are frequent and widespread phenomena triggered chiefly by intense or prolonged rainfall. Individual rainfall events can result in single or multiple slope failures in small areas or in very large regions, causing fatalities and large economic damage. Thus, assessing the rainfall conditions responsible for landslides is important and may contribute to reducing risk. Following a review of methods for establishing the dependence of landslide occurrence on rainfall. Next, we present the statistical method used for the definition of objective cumulated event rainfall-duration (ED) thresholds, and we show regional, lithological and seasonal thresholds in central Italy.