Cosmo-skymed and radarsat-2 joint analysis and modeling for the evaluation of potential deformations caused by the large mass movements surrounding the Fiastra lake dam.

In the last 20 years, many studies have identified the presence of Deep-seated Gravitational Slope Deformations (DGSD) in the central Apennine Mountains, particularly along the calcareous mountain ranges [1] [2]. They typically affect the whole hillslope for thicknesses higher than several tens of meters and lengths of some kilometers, and are generally characterized by low deformation rates. Slopes affected by DGSD generally present peculiar morphological and structural features, such as double crest lines, downhill-facing and counter-slope scarps, slope-parallel trenches, tension cracks and a general bulging at the lowermost portions of the slopes. Often such DGSD are located near strategic works such as highways, aqueducts and dams, making it necessary to monitor them, in order to prevent any possible damage to civil infrastructures. Among the different monitoring methods, Advanced Differential Radar Interferometry technique (A-DinSAR) [3], allows to quantify the surface deformation due to large gravitational phenomena. Indeed, ground velocities obtained from DinSAR time series analysis give quantitative information which can be used to support the geomorphological interpretation of the observed gravitational deformations. Also tomographic extensions of interferometric methods have been developed, in particular of 4D (3D + time) kind, allowing deformation measurements also in layover areas.