Using advanced InSAR time series techniques to monitor landslide movements in Badong of the Three Gorges region, China

The Three Gorges occupy 193 km of the middle reaches of the Yangtze River between Fengjie in Chongqing and Yichang in Hubei Province, China. Due to steep valley-side slopes and long-term river incision, landslides are a major hazard in the Three Gorges region. In this study, we employ the SBAS InSAR technique to process Envisat SAR images collected between 2003 and 2010. Our time series results enable identification of two distinct landslides with deformation rates of up to 10–15 mm/yr in Badong County, and field evidence is used to verify the positions of these failures. With both descending and ascending observations, two-dimensional velocity fields in north and up directions are recovered to better understand the landslide movements. Obvious correlation between seasonal landslide movements and water level changes is observed, which not only provides strong support of our InSAR time series results, but also indicates the impacts of water level changes to landslide activities.