Flow-like mass movements are among the most severe natural hazards. They often cause catastrophic consequences when involving pyroclastic soils. These soils are widespread all over the world, also in very high populated regions. Modelling the triggering mechanisms of these landslides is a fundamental step for the hazard assessment. Several approaches are available which, however, must be systematically checked through their application to well documented case histories. In this PhD Dissertation (University of Salerno, 2006) a general discussion is provided for these phenomena....