融合升降轨InSAR数据的东川区滑坡隐患识别

Identification of potential landslides in Dongchuan district by integrating InSAR data of ascending and descending orbits

为解决常规In SAR技术仅能获取一维视线上的形变,导致升、降轨监测的模糊性和差异性,难以全面完整识别出区域内滑坡隐患问题.本文利用小基线数据集技术,以云南东川区为研究对象,获取该区域2018年至2020年升轨和降轨Sentinel-1A数据,采用融合升降轨数据的方法,反演研究区垂直向和东西向二维形变场进行滑坡隐患识别,并结合遥感影像对识别结果的可靠性进行验证.实验结果显示:(1)研究区在升轨和降轨雷达视线方向上的形变速率分别为-188.1~88.9 mm/a、-163.6~74.7 mm/a,融合升降轨数据反演出的东西向形变速率为-123.9~136.7 mm/a,垂直向为-206.5~58.5 mm/a,说明研究区地表形变在垂直方向变化较大,相对于其他方向,沉降中心更为明显.(2)在单一轨道雷达视线向的升降轨形变结果中,分别有15和12个滑坡隐患区被识别;而在融合后所提取的垂直向形变场中,则有25个滑坡隐患区被探测,除升降轨所识别的区域外,还新增6处滑坡隐患.表明垂直向形变结果具有较好的监测能力,能够有效识别区域内滑坡隐患,弥补单一轨道在复杂山区应用的不足.(3)通过对融合结果中典型形变区的详细分析,发现上述区域无论是在形变量时间序列特征上,还是遥感影像的光谱纹理上,都呈现出明显的滑坡特性.证明了融合升降轨数据进行滑坡隐患识别的方法,具有较高的可行性和可靠性,能够为该区域的地质灾害防治提供一定的参考.

In order to solve the problem that conventional In SAR technology can only obtain the deformation on the one-dimensional line of sight,which leads to the ambiguity and difference in the monitoring of ascending and descending orbits and makes it difficult to fully and completely identify the landslide hazards in the region.In this paper,we use the small baseline dataset technique to obtain the ascending and descending Sentinel-1A data from2018 to 2020 in Dongchuan district,Yunnan province,and use the method of integrating the ascending and descending data to invert the vertical and east-west twodimensional deformation fields in the study area for landslide hazard identification,and validate the reliability of the identification results by combining remote sensing images.The experimental results show that:(1)the deformation rates of the study area in the direction of the radar line of sight of the ascending and descending tracks are-188.1~88.9 mm/a and-163.6~74.7 mm/a,respectively,and the deformation rates of the inverse performance of the integrated ascending and descending orbit data are-123.9~136.7 mm/a in the east-west direction and-206.5~58.5 mm/a in the vertical direction,indicates that the surface deformation in the study area is more variable in the vertical direction,and the subsidence center is more obvious compared to other directions.(2)A total of 25 landslide potential areas were identified in the vertical deformation results from the inversion of integrated ascending and descending orbits data,and 6 new landslide potential areas were added except the areas detected by the single track.better monitoring ability,which can effectively identify the landslide hazards in the region and make up for the shortage of single orbit in complex mountain applications.(3)Through detailed analysis of the typical deformation areas in the integration results,it was found that the above-mentioned areas showed obvious landslide characteristics both in the time series characteristics of deformation variables and in the spectral texture of remote sensing images.The method of fusing lift-track data for landslide hazard identification is proved to be highly feasible and reliable,and can provide some reference for geological hazard prevention and control in the region.