多平台多时域InSAR估计山岳冰川三维运动及物质平衡变化

Recently, mountain glaciers' melting and recession have been accelerated under the background of global warming. It exerts significant effects on the local vulnerable ecological environment, global climate and sea level rise. Glacier flow velocity monitoring can provide vital information for assessing its mass balance and stability. Currently, using InSAR to monitor mountain glaciers mainly focuses on its one- and two-dimensional flow velocity. However, as mountain glaciers generally locate at steep area, accurate estimation of its flow velocity must rely on high-precision three-dimensional motion measurements. This project proposes integrating multi-platform and multi-temporal InSAR observations to estimate mountain glacier's 3-D motion, and based on the results analyzing its motion patterns and assessing its mass balance variation and stability. The main content includes developing InSAR glacier topography refining method, investigating variance component estimation- and Kalman filter-based 3-D glacier motion velocity and time series estimation, analyzing the glacier's motion patterns, mass balance variations and stability based on the 3-D motion results. Through determining mountain glacier's motion pattern, mass balance and stability, the project will contribute to provide important scientific basis for ecological environment maintaining, water resource preservation, and glacier hazard prevention and mitigation. It will also put forward the advance of InSAR technology, and upraise our mountain glacier monitoring standard and sharp international competiveness in this field.

近年来，在全球气候变暖背景下山岳冰川加速消融和退缩，对冰川区脆弱的生态环境、全球气候和海平面变化产生了重要影响。冰川流速监测能为冰川物质平衡及稳定性评估提供重要信息。目前采用InSAR监测山岳冰川流速，主要集中在一维和二维。然而，山岳冰川普遍处于地形起伏大的区域，准确获取其流速必须建立在高精度三维形变监测的基础上。 本项目提出融合多平台、多时域InSAR观测值估计山岳冰川的三维运动，并基于此分析其运动规律、物质平衡变化及稳定性。具体包括发展多基线InSAR冰川地形精化方法，研究基于方差分量估计和卡尔曼滤波的三维运动速率和序列估计，基于高分辨率三维监测结果分析冰川的运动规律、物质平衡变化和稳定性。本项目不仅可以获取典型冰川的运动规律、物质平衡变化和稳定性结果，为维护区域生态平衡、保护淡水资源及冰川防灾减灾提供重要的科学依据；还可以推动InSAR技术的发展，提高我国山岳冰川监测水平和国际影响。

本项目首先开展了基于多基线InSAR 的山岳冰川地形残差估计研究，通过升降轨融合和基于外部控制点平差实现山岳冰川地形的精化和更新；然后，开展了基于方差分量估计的InSAR 山岳冰川三维运动速率估计和基于三维流速的冰川厚度变化估计；其次，开展了融合不同平台、轨道和时序InSAR数据的InSAR 山岳冰川三维形变估计，提高了SAR冰川三维流速观测的时间分辨率；最后，基于InSAR三维时序形变结果估计了冰川厚度变化和物质平衡，开展了基于影像大地测量方法的冰川厚度变化和物质平衡定量估计研究，发展了InSAR 和光学摄影测量定量估计山岳冰川物质平衡变化的技术，揭示全球气候变暖背景下典型山岳冰川的变化规律以及冰川消融对青藏高原湖泊扩张的贡献。.项目共发表论文27篇，其中SCI论文26篇，EI论文1篇，培养研究生10名；举办全国性学术会议1次，参加国际学术会议8次；参与获国家科技进步二等奖1项，湖南省科技进步一等奖1项，电力工程科学技术进步一等奖1项，中国卫星导航定位科技进步二等奖1项。