基于时序InSAR的理县清流村滑坡二维变形特征与影响因素研究

Two-dimensional deformation characteristics and influencing factors of the Qingliucun landslide in Lixian County by using time-series InSAR

【目的】滑坡灾害在中国西南山区频发,大量的滑坡灾害对区域内居民的生产生活造成了严重影响,因此,对滑坡灾害进行长时间序列监测以探究其变形特征十分必要。【方法】以2020年四川省理县清流村H01和H02滑坡事件为例,基于SBAS-InSAR方法反演了滑坡失稳前后的地表运动过程,联合上升和下降轨道数据并基于二维分解模型获取了滑坡的二维形变特征。【结果】结果显示,H01滑坡和H02滑坡的水平方向(E-W)最大变形速率分别为-43 mm/a和-9 mm/a,垂直方向(U-D)最大变形速率分别为-76 mm/a和-34 mm/a。【结论】结果表明,清流村滑坡在早期失稳之后一直处于不稳定状态,并且还有进一步失稳的趋势。为了进一步研究清流村滑坡的空间变形特征,还探究了降雨和重力作用对于H01滑坡和H02滑坡的影响。研究成果为山区小型滑坡的InSAR形变结果分析提供参考,并且可为清流村滑坡后续的风险管理提供支撑。

[Objective]Landslide disasters occur frequently in the mountainous areas of Southwest China,and a large number of landslide disasters have caused serious impacts on the production and life of the residents in the region,so it is necessary to carry out long time series monitoring of landslide disasters in order to explore their deformation characteristics.[Methods]In this paper,we take the landslide events H01 and H02 in Qingliu Village,Lixian County,Sichuan Province,in 2020 as an example,and invert the surface motion process before and after the landslide destabilisation based on the SBAS-InSAR method,and obtain the 2D deformation characteristics of the landslides based on the two-dimensional decomposition model by combining the ascending and descending orbital data.[Results]The result show that the maximum deformation velocity in the horizontal direction(EW)are-43 mm/a and-9 mm/a for landslide H01 and landslide H02,respectively,and the maximum deformation velocity in the vertical direction(U-D)are-76 mm/a and-34 mm/a for landslide H01 and landslide H02,respectively,[Conclusion]and the result show that the landslide in Qingliu Village has been in an unstable state after the early destabilisation,and there is a tendency of further destabilisation.In order to further investigate the spatial deformation characteristics of the landslides in Qingliu Village,the effects of rainfall and gravity on landslides H01 and H02 were investigated in depth.This study provides a reference for the analysis of InSAR result of small landslides in mountainous areas,and also provides support for the subsequent risk management of landslides in Qingliu Village.