InSAR-based monitoring of mass movements in Southern Kyrgyzstan using ALOS/PALSAR

Southern Kyrgyzstan is an area of high landslide activity causing significant damage every year. Since large areas are affected there is a big need for efficient methods for landslide monitoring. We use L-band ALOS/PALSAR imagery to analyze surface deformation related to gravitational mass movements. A total of 26 L-band ALOS/PALSAR raw data sets were received from JAXA covering the study area in South-ern Kyrgyzstan during a time period between 2007 and 2010. We applied SAR interferometry (InSAR) technique to identify surface changes which are the result of hillslope processes. In this study we present the results for the Kainama test site which has been subject to high landslide activity. The interferograms obtained by SAR interferometry analysis show very good coherence even though temporal resolution is more than 2 years over mountainous and vegetated terrain. Our InSAR derived results have been validated by field observations. It could be shown that InSAR analysis is capable to resolve the mobilization of mass movements in a quantitative way and thus indicate areas which are especially prone to experiencing landslide failures in the near future. The obtained results show the big potential of radar interferometry for monitoring of slope instabilities in Southern Kyrgyzstan.