基于InSAR技术的库水位波动诱发岸坡变形破坏时空演化规律研究——以金沙江溪洛渡水库为例

Deformation-Damages of Bank Slope (DDBS) induced by fluctuation of reservoir water level is a serious threaten to the safe operation of reservoir operation, so the recognition to evolution laws of DDBS is the foundation of disaster prevention and protection. As large area and dynamic occurrence of DDBS, the traditional engineering geology investigation and monitoring are not suit to carry out widely, which make that it improve slowly. Based on high-precision, large-covering, retrospected InSAR survey, this proposal will execute the study of DDBS in Xiluodu Reservoir on Jinsha River. Firstly, improve the special InSAR technology for fitting to the dry-hot Jinsha River valley environment, including combination observation plan of varied SAR data and incident angles, optimizing DEM, rectifying atmosphere delay model ect.; secondly, based on non-line deformation observed by the archived and archived-programming SAR data before and after impoundment, gain DDBSs in different time periods; furthermore, analyze the correlation between sequence DDBSs and water level fluctuation; lastly, achieves three goals: discovering the spatio-temporal distribution of DDBS, period effect of DDBS, as well as indication of exist deformation to DDBS after impoundment, and apply it to the evaluation of bank stability. This project have important scientific and practical signification for understanding the geological environmental effect of hydro-power development and supporting the construction of major projects.

库水位波动诱发库岸变形破坏是水库安全运行的重大威胁，对其时空演化规律的认识是库区减灾防灾的重要基础。由于库岸变形破坏范围大且持续时间长，传统的工程地质调查和监测工作不宜全面开展，导致了其研究进展缓慢。本项目以InSAR观测为主要技术手段，对溪洛渡水电站库岸开展研究。首先，优化InSAR技术方法体系以满足金沙江干热河谷岸坡变形观测要求，包括采用多角度、多分辨率SAR数据组合方案，优化高陡峡谷区DEM，研发干热河谷大气延迟模型等；其次，利用蓄水前存档与蓄水后存档-编程SAR数据联合观测岸坡非线性变形，提取不同时段的地质灾害信息；进而分析岸坡变形破坏与库水位波动的时空相关性；最终获得水位涨落致灾的空间分布、变形破坏的时段效应、先存微小变形对蓄水破坏指示作用等岸坡变形破坏的时空演化规律，并应用于库岸稳定性评价。本项目对于理解水电开发的地质环境效应和支撑国家重大工程建设有重要的科学意义与实用价值。

系统的完成了中国第二大水电站溪洛渡库区岸坡InSAR与高分辨率遥感观测，获取了长期、精确的变形监测值，有效的识别了库区滑坡发育变化。首次揭示了巨型库区受水位波动影响的岸坡变形破坏时空发育分布规律。对典型岸坡的变形破坏进行了InSAR监测与稳定性分析，并探索了基于InSAR数据的预警方法。构架综合遥感应用于滑坡防控全过程的理论框架并初步实践。有力促进了中国地质调查局的地灾InSAR技术进步与国际合作交流，举办了全国性的“地质灾害InSAR监测技术研讨与交流会”，推进了InSAR技在地质灾害防治领域的应用，支撑了所在单位的科技支撑平台的建设，实现成果转化合同额金额563万元，成果尚有进一步深入转化的潜力。