The Sbas-dinsar Approach for the Spatial and Temporal Analysis of Sinkhole Phenomena

Sinkholes represent the main hazards in karst areas, and are related to presence of natural and anthropogenic cavities. In order to mitigate the risk related to sinkholes, identification of likely premonitory signs preceding the catastrophic phase of collapse may be extremely important. Remote sensing and surface monitoring can be used at this aim: multi-pass spaceborne Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques, in particular, provide a valid support to remotely investigate the sinkhole susceptibility over large areas and long time intervals. In this work, we analyze surface deformation occurring in Apulia region, Southern Italy, at two spatial scales. In particular, we apply the advanced DInSAR approach referred to as Small BAseline Subset (SBAS) for carrying out regional scale analysis and the 4-D (space velocity) imaging technique for investigating deformation phenomena at local scale. We exploit ascending ENVISAT images spanning the 2003-2010 period and analyze subsidence phenomena induced by both natural and anthropogenic factors.