Rainstorms as a landslide-triggering factor in Slovenia

Rainfall plays an important role in the landslide triggering processes. Analyses of landslide occurrence in the area of Slovenia have shown that areas where intensive rainstorms occure (maximal daily rainfall for the 100 years period), and where the geologicalsettings are favourable, abundance of landslide can be expected. This clearly indicates the spatial and temporal dependence of landslide occurrence upon the intensive rainfall. Regarding the landslide occurrence, the intensity of maximal daily and average annual rainfall for the the 30 years period were analysed. Results have shown that daily rainfall intensity, which significantly influences the triggering of landslides, ranges from 100 to 150 mm, most probably above 130 mm. Despite the vague influence, if any at all,of the average annual rainfall, the threshold above which significant number of landslides occurs is 1000 mm.