Shallow flowslides triggered by intense rainfalls on natural slopes covered by loose unsaturated pyroclastic soils

The twentieth century is notable for a number of catastrophic landslides, involving essentially granular soils of pyroclastic origin, triggered by rainfall in a wide region around the town of Napoli. In particular, on 5 May 1998 a number of large flowslides killed 160 people (Cascini et al., 1998), but many other killer landslides of the same type have occurred in the last 20 years. Also, old chronicles report catastrophic landslides mobilised in the same area in previous centuries. The problem is hence recurrent, although in more recent years catastrophic flowslides seem to be much more frequent. There...