Landslides, and in a more general sense, mass movements, cause severe damages both in terms of casualties as well as in terms of economic losses. Silent mass movements are so frequent that the cumulative damage caused by these unspectacular phenomena may even exceed the ones caused by disastrous landslide events.

The damages in economic terms, only considering the European Union, amount to several billion of $. Nonetheless, the publicity of these phenomena is quite low because of their often unspectacular development and because the limited extensions of the zones concerned by a single event. Disasters like floods or earthquakes are less frequent but huge areas may be destroyed by a single earthquake or flood with thousands and thousands of deaths. A UNESCO study, however, reports that the fatalities caused by landslides amount to 15% of the total number of victims of natural disasters.

This number, together with the increasing density of population and sensitive facilities bearing a high secondary highlight the necessity of accurate studies of landslide and mass movement risk with the scope of a better land-use and emergency planning.

The activities of Mestor concerning landslide risk are:

• Studies devoted to a better understanding of the phenomenon and the controlling factors
• Definition of landslide hazard on the base of various data sources, i.e., spaceborn data, data from field campaigns, historical data
• Development of monitoring methods on regional and national scale
• Development of slope instability models providing objective criteria for the assessment of local and social landslide and mass movement risk