基于雷达遥感的大型水电工程库岸边坡及大坝稳定性监测方法研究

The problem of safety monitoring of dams and reservoirs is receiving more and more attention along with the rapid and large-scale developments of hydropower projects in southwestern China in recent years. Satellite Synthetic Aperture Radar (SAR) remote sensing technology such as differential SAR interferometry (DInSAR) has shown unique capabilities and various potential applications in the field of landslide detection and monitoring across wide reservoir areas. Nevertheless, for practical applications of SAR remote sensing in mountainous and valley areas of southwestern China, there are still crucial problems in current studies that remain unsolved up to now in aspects of SAR acquisition plan making, potential landslide detection and identification, accurate measurement of surface deformation, as well as highly efficient mode of time series InSAR data processing and analysis..Aiming at these problems, in this project we will firstly develop an approach of optimizing satellite SAR acquisition plans for landslide monitoring in reservoir areas through applicability evaluation of various SAR observation modes and system parameters. Then, we will try to solve the problem of potential landslide identification across wide reservoir area by combining DInSAR analyses and landslide expert knowledge base. Afterwards, the methodology and approach of joint utilization of various SAR remote sensing techniques including multi-temporal InSAR (MT-InSAR), multiple aperture interferometry (MAI) and pixel offset tracking (POT) will be developed and implemented to accurately measure surface displacements of reservoir bank slopes and dams with single/multi-track SAR observation datasets. At the same time, we will explore new modes of time series InSAR data processing and analysis to meet the emerging requirements of near-real-time routine monitoring applications. Finally, a methodological application framework of satellite SAR remote sensing technology for stability monitoring of bank slopes and dams will be established as an efficient tool for geohazard detection and surveillance in reservoir areas.

随着近年来我国西南地区水电资源加速密集开发，坝库安全监测的必要性和重要性日益凸显，以差分干涉测量为代表的卫星雷达遥感技术在大范围库区滑坡普查监测方面具有独特的优势和广阔的应用潜力。然而对于众多水电工程所处的西南高山峡谷地区来说，现有相关方法和应用研究在雷达数据获取方案制定、潜在滑坡探测识别、形变信息精确提取、时序数据处理模式等方面还存在诸多亟待解决的突出问题。针对这些问题，本项目拟首先从开展雷达遥感适用性条件分析入手，研究建立面向库区的星载SAR观测模式与系统参数优化选取准则，发展差分干涉测量与滑坡专家知识相结合的潜在滑坡识别新途径，在此基础上，研究综合利用时序差分干涉测量、多孔径干涉测量和偏移量跟踪等雷达遥感技术高精度提取库岸边坡及大坝表面形变信息的方法途径，同时探索适合业务化准实时监测需求的时序差分干涉测量数据处理新模式，最终构建基于卫星雷达遥感的库岸边坡及大坝稳定性监测方法技术体系。

随着近年来我国西南地区水电资源加速密集开发，库岸边坡安全监测的必要性和重要性日益凸显，以差分干涉测量为代表的卫星雷达遥感技术在大范围库区滑坡普查监测方面具有独特的优势和广阔的应用潜力。然而对于众多水电工程所处的西南高山峡谷地区来说，现有相关方法和应用研究在雷达数据可用性评价、潜在滑坡探测识别、形变信息精确提取、时序数据处理模式等方面还存在诸多亟待解决的突出问题。针对这些问题，本项目首先从开展雷达遥感适用性条件分析入手，研究提出了面向广域山区的星载SAR数据有效性和可用性的评价指标和技术方法，并以贵州全省地质灾害隐患排查为实例开展了验证应用；在此基础上，分别面向缓慢变形的和快速滑动的两大类滑坡体，提出发展了综合利用点目标与分布式目标的相干散射体时序InSAR方法（CSI）和点目标时序偏移量追踪方法（TS-PTOT），实现了不同量级的滑坡体表面形变场的准确有效提取，为山区滑坡灾害隐患的识别监测提供了有效的技术手段支撑；同时，考虑到西部山区普遍存在的大气对流层传输延迟对于时序InSAR相位测量的干扰影响问题，提出构建了顾及大气延迟改正的精细化时序InSAR处理流程，改善了形变测量结果精度和可靠性；面向三类不同约束条件下的滑坡监测应用场景，分别提出实现了相应的三维形变场反演技术途径；以典型滑坡灾害为实例，探索研究了基于密集时序星载SAR观测动态更新处理进行早期预警与失稳成灾时间预测的可行性和方法途径。综合以上研究成果，初步构建形成了基于卫星雷达遥感的西部山区大型滑坡稳定性监测方法技术体系。