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 which triggered landsliding. Thus, identification and monitoring of slowly moving landslides is of particular interest. Our investigations demonstrated efficiency of INSAR application to locate and monitor activity of slowly moving landslides there. We studied the landslide activity in the area of the Bolshoy Sochi (Big Sochi) using the StaMPS software. We incorporated radar images from the satellites with different wavelengths from ascending and descending orbits: 13 Envisat images (track 35D, descending orbit, 14.08.2003-09.02.2006), 12 Envisat images (track 35D, descending orbit, 2007.11.01-08.07.2010), 13 Envisat images (track 35D, descending orbit, 29.11.2010-23.03.2012), 11 Envisat images (track 85A, ascending orbit, 01.08.2004-01.02.2009), 17 ALOS images (track 588A, ascending orbit, 22.01.2007-17.09.2010), 17 TerraSAR-X images (track 54A, ascending orbit, 24.12.2011-13.09.2012). We present results of processing of all these data sets for the Moldovka landslide which is a typical representative of slowly moving landslides on the Black Sea coast of the Northern Caucasus being of particular interest as it is situated nearby theSochi airport. The Moldovka landslide is an ancient landslide in the Chvizhepse folded area. Displacements of this landslide became visible and were fixed by ground methods after heavy rainfalls in winter-spring 2012. The boundaries of the Moldovka landslide were clearly determined applying the Stamps technique to the above mentioned data sets. Analyzing the time series it was found out that displacements of the landslide took place starting at least in 2004. Analyzing all the deformation maps and time series we determined the LOS displacement rates in 2004-2013 being about 20-30 mm/Y with several accelerations induced by rainfalls. Maximum estimates of displacement rates in the down the slope direction were revealed in the first months of 2012 being about 150 mm/Y . For atmospheric corrections we used the TRAIN software which appeared to be the most effective for the TSX data. Using the TRAIN software improved the results of the processing of the TSX data - boundaries of the landslide on the deformation map became more clearly seen and several new slowly moving zones became visible. @en

The landslide activity in the area of Bolshoy Sochi (Big Sochi) situated at the Black Sea coast of the Great Caucasus has been studied using the StaMPS PS-InSAR method. We incorporated three sets of radar images from the satellites with different wavelengths ALOS, Envisat and Terra-SAR-X from both ascending and descending tracks which cover the time period from January 2007 to September 2012. Comparative investigation of surface displacements obtained from all the data sets is presented. Areas where high surface displacement rates have been located on the base of the satellite data coincide well with zones of high landslide activity according to ground observations. We constructed time series for the two landslides: in the Baranovka and Mamaika villages where considerable surface movements had been observed during the time of acquisitions. Analysis of the time series made it possible to determine periods of activity and relative stability of the landslides and compare them with ground observations.@en