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Mass movements of different thicknesses and types affect the slope where the Greci and Piscopie villages lie (Lago, Calabria, Italy). The study concerns a moderately urbanized area where the lithological, structural, and hydrogeological conditions have produced a large and complex unstable area. In the study area, a multi-temporal field survey has allowed for detailed landslide inventory mapping and definition of the geometric and kinematic characteristics of mass movements with long-term monitoring. In particular, an integrated monitoring network was progressively put in place, since 1996 to measure superficial and deep displacements (GPS stations and inclinometers). The network dataset shows that the mass movements in the study area are characterized by an extremely slow or very slow rate of displacement. The elements acquired by a long-term monitoring of the deep displacements point out that the landslide bodies are prone to develop new failure surfaces progressively shallower, with a consequent increase of the hazard. Moreover, medium-deep and deep-seated landslides may rapidly accelerate in relation to rainfall conditions and significantly affect structures and infrastructures. The integration of the geological and geomorphological knowledges with the monitoring data allows for distinguishing six different homogeneous sectors on the slope, as well as the relative geometric and kinematic characteristics, and the type of mass movements. In the study area, which is representative of several aspects of other areas, the method proposed and the knowledge acquired by long-term monitoring could be useful to define mass movement mechanisms, geotechnical models, and risk mitigation strategies. [ABSTRACT FROM AUTHOR]

Calabria is one of the Italian regions mostly affected by mass movements. The case study of a densely populated neighborhood (Ianò) located in the central-western sector of Calabria is presented. The several landslides triggered in February 2010 caused heavy damages to the built area, infrastructures and productions of this neighborhood, and increased the risk for the inhabitants. The results obtained through field surveys, photo interpretation, analyses of rainfall data and of the urban fabric evolution, historical survey on the reports of the damages caused by landslides, have enabled to formulate hypotheses on the potential causes that triggered landslide events and produced severe consequences on the area. These results have revealed that almost all landslides of February 2010 are partial reactivations of pre-existing landslide deposits. Moreover, the analyses have indicated a critical role of cumulative rainfalls over an interval of 15 days. However, the severe damage framework is explained through an unplanned urbanization which took place across the years on an area characterized by a high level of instability per se. Some buildings have been erected in proximity of or within pre-existing landslide scarps; in other cases, buildings have been constructed even inside the landslide bodies. [ABSTRACT FROM AUTHOR]