Large Slow-moving Rock Slides – Earth Flows: the Case Study of Ca’ Lita Landslide (Northern Apennines, Italy).

The Ca’ Lita landslide is a large and deep-seated mass movement located in the northern Apennines of Italy. It consists of a complex-composite landslide that affects Cretaceous to Eocene flysch rock masses and chaotic complexes. The landslide head zone resumed activity in 2002 and in 2004 the landslide was totally reactivated. More than 50 m retrogression of the scarp, and about 400 m advancement of the toe threatened villages and an important road connecting several key industrial facilities located in the upper watershed. A national state of emergency was declared by the Authorities, following the evolution of 2004. A large plan of civil protection interventions was implemented, aimed at the management of risk and at the identification and realisation of structural mitigation. The Ca’ Lita landslide is a noticeable case history both from the geomorphic and the risk management perspectives. The relatively fast evolution undergone by the phenomenon from 2002 to date, and the remarkable advancement of the toe, point out that total and partial reactivations of dormant landslides can cause unexpected consequences in terms of involvement of new areas that, in practice, have no previous hazard rating assigned. Also, the landslide is a test bed for coupled monitoring and mitigation actions that, in a relatively short time, have allowed passing from response, to mitigation and preparedness phases. In this work, the management of the emergency is presented in the frame of monitoring, mitigation and modelling activities that are the result of the shared effort of public offices and research institutes.