On the Use of Ground-Based SAR Interferometry for Slope Failure Early Warning: the Cortenova Rock Slide (Italy)

Abstract

This contribution illustrates the capabilities of ground-based SARinterferometry (GBInSAR) to be used as an early warning for thedetection of precursory ground displacements that can suggest theimminent occurrence of a slope failure. SAR data were acquired by aground-based SAR system, belonging to the LISA interferometer seriesdesigned by the Joint Research Centre of the European Commission, overthe Cortenova rock slide (Regione Lombardia, Italy) andinterferometrically analyzed in near-real time. The system was used toprovide, during the 2002-2003 emergency caused by the landslidereactivation, the civil protection authorities with an operational toolfor the assessment of the mass movement temporal evolution. After themain rupture occurred at the beginning of December 2002, which causedsevere damage to the Bindo Village, destroying several houses andfactories, interrupting one key connection road and partially damming ariver, concern over the occurrence of further collapses of the stillunstable slope led to the evacuation of 900 people living close to therun-out area. Such a situation induced the civil protection authoritiesto arrange a real-time monitoring system. Measurements of grounddisplacements continuously collected by the radar system up to May 2003,besides detecting the portions of the slope affected by movement,revealed the gradual deceleration of the residual movements passing from5 cm d(-1) to 0.3 cm d(-1).