Investigation and monitoring in support of the structural mitigation of large slow moving landslides: an example from Ca' Lita (Northern Apennines, Reggio Emilia, Italy)

The Ca' Lita landslide is a large and deep-seated mass movement located in the Secchia River Valley, in the sector of the Northern Apennines falling into Reggio Emilia Province. about 70 km west of Bologna (Northern Italy). It consists of a composite landslide system that affects Cretaceous to Eocene flysch rock masses and chaotic complexes. Many of the components making up the landslide system have resumed activity between 2002 and 2004, and are now threatening some hamlets and an important road serving the upper watershed area of River Secchia, where many villages and key industrial facilities are located. This paper presents the analysis and the quantification of displacement rates and depths of the mass movements, based on geological and geomorphological surveys, differential DEM analysis, interpretation of underground stratigraphic and monitoring data collected during the investigation campaign that has been undertaken in order to design cost-effective mitigation structures, and that has been conducted with the joint collaboration between public offices and research institutes.