西藏樟木口岸震后滑坡灾害变形InSAR监测分析

位于中国和尼泊尔边境的西藏樟木口岸是国家一类陆路通商口岸，也是西藏最大的边贸中心口岸。2015年尼泊尔大地震之后，西藏樟木口岸因多次发生滑坡灾害，而导致口岸关闭。为了调查樟木口岸区域滑坡灾害的分布和变形情况及更好的服务于区域减灾防灾，利用InSAR技术对覆盖该区域的Sentinel-1A和ALOS-2两种卫星影像数据进行了处理，并通过分析视线向年均形变速率图，圈定了17处疑似滑坡，并对其中的5处典型滑坡进行时间序列形变特征分析，监测识别出的滑坡基本沿318国道所在一侧的波曲河左岸分布。InSAR调查结果表明受地震影响樟木地区的滑坡多分布在沿波曲河左岸的陡峭山体上，中尼公路迪斯岗至友谊桥段的古滑坡出现了局部复活的现象，同时樟木镇居民所在的城区也发育有扎美拉山危岩体崩塌滑坡灾害。 

InSAR monitoring and analysis of landslide deformation after the earthquake in the Zhangmu Port, Tibet

The Zhangmu Port, located on the border between China and Nepal, is a national first-class land trading port and the largest border trade port in Tibet. After the Nepal earthquake in 2015, the Zhangmu port was closed due to multiple landslide disasters. In order to investigate the distribution and deformation of landslide disasters in the Zhangmu port area so as to serve regional disaster mitigation and prevention, the InSAR technology was used to process the satellite image data of Sentinel-1A and ALOS-2 covering the area, and by analyzing the annual average rate map of line-of-sight deformation, 17 suspected landslides were delineated, and the time series deformation characteristics of 5 typical landslides were analyzed. From the distribution point of view, the landslides identified by monitoring are basically distributed along the left bank of the Boiqu River on the side of National Highway 318. InSAR survey results show that the landslides in the Zhangmu area affected by the earthquake are mostly distributed on the steep hills along the left bank of the Boiqu River. The ancient landslides on the section of Disigang to Youyi Bridge on the China-Nepal Highway have partially resurrected, and the Zhameila dangerous rock mass collapses and landslides are also developed in the urban area where residents live in Zhangmu Town.