Analysis of the deep-seated gravitational slope deformations over Mt. Frascare (Central Italy) with geomorphological assessment and DInSAR approaches

A quantitative and innovative DGSD (deep gravitational slope deformation) assessment method that used integrated remote sensing was tested in the central Apennine mountain range (Italy). The movement rate was calculated for selected test areas using the differential SAR interferometry small baseline subset (SBAS) technique. The selected test areas were previously identified by interpreting both aerial photos and using 32 ERS radar images taken between 1993 and 2000. More than 15 cm of cumulative surface displacement occurred across the Podalla DGSD along the satellite line of sight (LoS). Moreover, the displacement time series showed non-linear deformation rates, which included periods of accelerated movement correlated with strong rainfall. The high estimated Podalla DGSD activity indicates that this type of study should be conducted to monitor the evolution of this phenomenon. In addition, the DInSAR movement rate can be used to improve mapping and identify DGSDs in specific landscapes.