Infrared thermographic surveys for landslide mapping and characterization: the Rotolon DSGSD (Norther Italy) case study

On November 4th 2010, after several days of intense rainfall, a huge mass (about 225000 m3) detached from the debris cover of the Rotolon landslide, converging within the Rotolon Creek river bed, and evolving into a mobile debris flow that damaged various infrastructures, putting on high risk three villages located along the creek banks. After this event the National Department of Civil Protection (DPCN) appointed the Earth Sciences Department of the Firenze University (DST-UNIFI) to start a GB-InSAR (ground based interferometric synthetic aperture radar) monitoring activity, in order to support the local authorities for the emergency management by analyzing the landslide displacements and evaluating the residual risk. During this phase accurate geomorphological and infrared thermographic (IRT) surveys were also carried out, in order to study the landslide morphological features, with the aim of improving the radar displacement data interpretation. The obtained geomorphological map suggests that the debris production and detachment are hazardous phenomena that involve the surficial detrital cover of a bigger and more complex landslide. The latter has the characteristics of a deep seated gravitational slope deformation (DSGDS).