基于时序InSAR的雅鲁藏布江色东普流域冰崩碎屑流运动区地面变形研究

Study on the Surface Deformation of Ice Avalanche Debris Flow Movement Area in Sedongpu Basin of Yarlung Zangbo River Based on Time Series InSAR

以雅鲁藏布江色东普流域冰崩碎屑流运动区为研究区,选取2016-2020年91景降轨Sentinel-1A合成孔径雷达(SAR)数据,采用小基线集(SBAS)方法获取了色东普流域冰崩碎屑流运动区地面变形数据,并分析了地面变形的空间特征及时间规律.结果显示,色东普沟上部冰崩区、中部流通区及下部堆积区地表均以下沉为主,堆积区下沉幅度最大.变形时间序列显示,上部冰崩区在冰崩事件前均未发现明显的加速变形规律,中部流通区在冰崩事件前后未见显著变化,而下部堆积区在冰崩事件后都出现了先堆积抬升后侵蚀下沉的规律.研究也表明时序合成孔径雷达干涉(InSAR)技术在冰崩灾害监测方面有着很大的优势,InSAR变形结果有助于了解冰崩事件的发生机理及冰崩碎屑流运动特征,可为冰崩灾害防灾减灾提供科学依据.

In this paper,taking Sedongpu Basin of Yarlung Zangbo River as the research area,we use 91 scenes of Sentinel-1A SAR data from 2016 to 2020 in descending orbit to obtain the surface deformation of the ice avalanche debris flow movement area by SBAS method,and then the spatial and temporal characteristics of the surface deformation are analyzed.The results show that the upper,middle and lower parts of Sedongpu gully show the tendency of subsidence,and the downstream accumulation area has the largest subsidence.The deformation time series show that there is no obvious accelerated deformation in the upper reaches before the ice avalanche events,and there is no significant deformation in the middle reaches before and after the ice avalanche events,while the lower reaches appears accumulation and uplift before the ice avalanche events and subsidence after the events.This study also shows that time series InSAR technology has great advantages in ice avalanche disaster monitoring in the high mountainous area.InSAR deformation results help to understand the ice avalanche dynamics and the movement of the debris flow caused by ice avalanche,which can provide scientific basis for ice avalanche disaster prevention and mitigation.