ИСТИНА

The Black Sea coast of the Great Caucasus has always been a region of high landslide risk due to widely spread clays and marls seasonally saturated by abundant rainfalls. In recent years landslide risk assessment has become vital because of strongly increased human-induced impact dealt with construction of the Sochi-2014 Olympic Games facilities. We studied the landslide activity in mainly the area of the Bolshoy Sochi (Big Sochi) using different INSAR methods: the StaMPS PS-InSAR and SBAS methods, DEPSI, NSBAS, offset tracking. We incorporated radar images from the satellites with different wavelengths: 17 ALOS images (track 588A, ascending orbit, 22.01.2007-17.09.2010), 13 Envisat images (track 35D, descending orbit, 29.11.2010-23.03.2012), 17 TerraSAR-X images (track 54A, ascending orbit, 24.12.2011-13.09.2012). StaMPS appeared to provide the best results for this area. For all of these three sets of images we present deformation maps in the line of site (LOS) direction. Areas of relatively high surface displacement rates located using the SAR data appeared to match in many instances zones of high landslide activity identified by geological field observations. We identified all well known landslides where movements were fixed during the time of acquisitions according to ground data.