甘肃黑方台黄土滑坡InSAR识别、监测与失稳模式研究

Research on Loess Landslide Identification, Monitoring and Failure Mode with InSAR Technique in Heifangtai, Gansu

采用合成孔径雷达干涉测量(interferometric synthetic aperture radar,InSAR)技术对甘肃黑方台地区潜在的黄土滑坡开展了多时相编目、长时序监测以及失稳模式识别研究。首先,采用不同空间分辨率、不同波长的历史存档合成孔径雷达(synthetic aperture radar, SAR)数据对黑方台地区2006-12至2017-11间的潜在滑坡开展了识别研究,在2006-12至2011-03和2016-01至2016-11两个时间段均识别出数10处不稳定坡体,实地调查和光学遥感影像验证了InSAR技术识别结果的可靠性与准确性。然后,对典型不稳定滑坡体采用高空间与高时间分辨率的TerraSAR-X数据开展了长时序监测,结果表明,在InSAR监测期间,累积形变最大的滑坡体在随后的时间里均发生了滑动,并成功地捕获到滑坡体形变加速的时间点。最后,利用升降轨SAR数据开展了黄土滑坡二维形变监测研究,基于滑坡的二维形变特征并结合地形图以及光学遥感影像进一步研究了滑坡的失稳模式,现场调查结果验证了所获得滑坡失稳模式的准确性。

The interferometric synthetic aperture radar(InSAR)technique is used over Heifangtai loess terrace,Gansu province of China to map the distribution of potential loess landslides,the evolution of landslide deformation and the failure mode.Firstly,the archived synthetic aperture radar(SAR)datasets with different spatial resolutions and wavelengths from December 2006 to November 2017 are used to identify the potential landslides.Tens potential landslide areas are identified from December 2006 to March 2011 and from January 2016 to November 2016.Field investigation and optical remote sensing images validate the reliability and accuracy of the identified landslides.Then,the TerraSAR-X data with high spatial and temporal resolution are used to monitor the time series deformation of the typical unstable slopes.Results demonstrate that the landslides with the large accumulative deformation all occur in the following time,and the acceleration dates of failed landslides are successfully captured by InSAR time series results.Finally,two-dimensional deformation monitoring of loess landslide is conducted by combining with ascending and descending SAR datasets.The landslide failure mode are analyzed in depth according to the obtained two-dimensional deformation results,topographic map and remote sensing images.The accuracy of the obtained result is verified by field investigation.