基于光学与SAR数据的贵州发耳镇尖山营滑坡监测研究

Monitoring of Jianshanying Landslide in Fa’er Town,Guizhou Province Based on Optical and SAR Data

以贵州省发耳镇尖山营滑坡为研究对象,利用Google Earth历史影像、Sentinel-1 SAR影像及Sentinel-2光学影像,采用目视解译、SBAS-InSAR和光学偏移量技术对该滑坡的二维形变及时间序列变化特征进行监测研究,揭示其形变演化的过程及特征。多期Google Earth历史影像的对比表明,滑坡体面积呈逐年增长趋势,且2018年以后增长加快;SBAS-InSAR监测结果表明,尖山营滑坡年均形变速率达-150 mm/a,形变主要发生在滑坡体的前缘,且滑前累积达-108 mm;基于Sentinel-2影像的光学偏移量跟踪技术揭示该滑坡2016~2021年二维形变时间序列特征,补充SBAS-InSAR技术无法获取的滑坡主体的形变信息,结果表明,该滑坡最大累积形变量东西向达32 m、南北向达-52 m;对滑坡的二维时间序列进行特征点以及剖线分析发现,该滑坡形变与煤矿的重复开采和降水等因素有关。

This study focuses on the Jianshanying landslide in Fa’er town,Guizhou province and utilizes Google Earth historical images,Sentinel-1 SAR images,and Sentinel-2 optical images to monitor the two-dimensional deformation and time series of the landslide through visual interpretation,SBAS-InSAR,and optical offset techniques.The comparison results of multiple periods of historical Google Earth images indicate a year-by-year increase in the slope area of the landslide,with faster growth observed after 2018.The SBAS-InSAR monitoring shows an average annual deformation rate of-150 mm/a for Jianshanying landslide,with most of the deformation occurring at the slope’s front.The cumulative deformation before sliding is-108 mm.The optical offset tracking technology using Sentinel-2 images revealed the 2D deformation time series of a landslide from 2016 to 2021,providing additional information on the landslide body’s deformation that SBAS-InSAR technology could not capture.Results show a maximum cumulative shape change of 32 m in the east-west direction and-52 m in the north-south direction.By integrating the two-dimensional time series results of Jianshanying landslide with geological exploration data,rainfall patterns and other relevant factors,we determine that the deformation of the landslide is closely linked to recurrent mining activities as well as precipitation events.