REMOTE MONITORING OF A LANDSLIDE USING AN INTEGRATION OF GB-INSAR AND LIDAR TECHNIQUES

Landslide monitoring activities are of paramount importance for landslide hazard and risk assessment. They allow predictions to be made of the phenomenon evolution which can be used to define risk scenarios, especially when urban areas and infrastructures are involved. Over the last decades, spaceborne and, more recently, ground-based interferometric synthetic aperture radar (GB-InSAR) have been successfully used to identify and classify landslides. Ground-based synthetic aperture radar (GB-SAR) interferometry has already been recognized as a powerful tool, that can be considered complementary or alternative to spaceborne SAR interferometry for terrain monitoring and to detect structural changes in buildings. Terrestrial laser scanning (TLS) is a technique increasingly used in remote sensing of unstable slopes. Detailed digital models of the observed surface are generated with centimetric resolution. In particular, if multitemporal scans of the same area are performed, these scans can be compared in order to obtain displacement fields. Both GB-SAR and TLS observations were planned at the end of July 2007 and at the end of October 2007 in order to assess the hazard of a quarry that is subject to ground instabilities (the Ex-Locatelli quarry near the Baveno village in the Italian Alps on Lake Maggiore). This paper reports on these measurement campaigns and on a test site set up in Florence (Italy) and discusses the advantages of the combined use of these innovative techniques. The availability of radar and laser data at the same time has allowed a comparison to be made of the two techniques and has provided an effective validation test for both