基于卫星PS-DS InSAR的龙门山断裂带滑坡监测与反演

Due to the special geomorphology and geological settings, the Longmenshan faulting system (LFS) in Sichuan (China) with frequent occurrence of earthquakes possesses many potentially disastrous landslides, thus already causing enormous casualties and economic loss. It is very important to carry out monitoring and analyzing of the large-scale landslides along the LFS. However, such work has not been started yet due to some apparent limitations of the conventional monitoring techniques. This research project will concentrate on investigation on monitoring and inversing of landslides along the LFS through developing the PS-DS InSAR technique. The objective of this project is to explore an effective approach for monitoring landslides in a large region and analyzing their evolution process. The primary strategies are provided here. We will extend the theory and models of multi-temporal interferometric synthetic aperture radar (InSAR) with a combined use of both point scatterers (PS) and distributed scatterers (DS). Such method can be abbreviated and termed as PS-DS InSAR. With use of SAR images collected along ascending and descending orbits of multi satellites, the distribution of landslides and their spatiotemporal evolution will be assessed and analyzed. The physical models of the typical landslides selected in the study area will be inversed using the deformation time series. Such strategies proposed will be useful for raising the accuracy and reliability of monitoring and inversing of landslides in a large region. The primary research contents of this project include backscattering characteristics of PS/DS and their automated detection, phase analysis and optimized processing, PS-DS InSAR modeling and deformation estimation, data fusion and inversion of landslides.

因特殊地貌及地质构造，地震频发的四川龙门山断裂带存在大量滑坡灾害隐患，并已造成人员伤亡和巨大经济损失，及时开展龙门山断裂带滑坡监测与分析至关重要。然而，受常规监测技术劣势的制约，该区域的全局性滑坡监测始终未能全面展开。本项目将针对"基于卫星PS-DS InSAR的龙门山断裂带滑坡监测与反演"展开研究，旨在为大范围滑坡监测及其演变规律分析探索有效的技术途径。其基本思路是：在扩展面向点散射目标(PS)和分布型散射目标(DS)的时序雷达干涉理论与模型的基础上，使用多卫星平台所获取的升降轨SAR影像对滑坡点分布及其形变时空演变进行普查、评估与监测，利用形变时序数据对典型滑坡进行物理模型反演，从而提高大范围滑坡普查、评估及其位移监测与反演的精度与可靠性。本项目将针对PS/DS散射特性及其自动探测、PS/DS相位分析与优化处理、PS-DS InSAR建模与形变计算、数据融合与滑坡反演等进行深入研究。

考虑到四川龙门山断裂带大范围内滑坡监测的特殊性、紧迫性和挑战性，本项目提出对“基于卫星PS-DS InSAR的龙门山断裂带滑坡监测与反演”进行系统研究，旨在为我国大范围内滑坡监测及其演变规律分析探索有效的技术途径。主要工作内容为沿四川龙门山断裂带选取典型实验区域，在扩展面向点散射目标(PS)和分布型散射目标(DS)的时序雷达干涉理论与模型的基础上，使用多卫星平台所获取的升降轨高分辨率SAR影像对滑坡点分布及其时空演变进行普查与评估，融合高时空分辨率形变数据对典型单体滑坡进行物理模型反演，从而提高大范围滑坡普查、评估及其位移监测与反演的精度与可靠性。本项目重点针对PS/DS目标散射特性及其自动探测、PS/DS相位分析与优化处理、PS-DS InSAR 建模与形变计算、数据融合与滑坡反演等方面进行深入系统的研究，取得了较好的研究成果。本课题的研究对我国滑坡监测、地质灾害普查以及区域环境保护具有重要的现实意义。.课题组成员依托项目资助开展了积极的研究，取得了较好的研究成果和较大的社会影响力。项目组成员在项目的研究过程中，撰写了科研论文34篇，其中SCI论文20篇，EI论文5篇，中文核心论文6篇，会议论文3篇。研发了InSAR数据处理软件2套，申请了实用新型专利3项、国家发明专利4项、软件著作权2项，并培养了研究生20余名。此外，借助雷达遥感技术的优势，在科技部国家遥感中心的协调下，课题组开展了国务院办公厅遥感监测信息服务工作，并上报了《四川省茂县滑坡灾区高风险区域遥感监测分析报告》、《长江中游石首-岳阳-武汉段水情遥感监测报告》和《四川省九寨沟县7.0级地震灾情遥感监测分析报告》等3期遥感监测报告，报告已被国务院办公厅“全国空间信息系统”收录，充分发挥了雷达遥感信息技术的优势，获得了相关部门的高度重视，在防灾减灾工作中发挥了重要作用，取得了较大的社会影响力。