基于SBAS-InSAR技术的山早滑坡形变分析

Deformation Analysis of Shanzao Landslide Based on SBAS-InSAR Technology

台风暴雨诱发滑坡具有突发性,调查难度较大。以台风“利奇马”期间发生的山早滑坡为例,基于滑坡发生前的升轨哨兵一号2017年9月12日至2019年8月9日的24景数据,采用SBAS-InSAR技术分析了该时段滑坡的时序累积变形,并结合气象资料进一步分析了滑坡体地表形变的规律。结果表明,山早滑坡发生前的形变主要划分为滑坡体蠕变阶段、滑坡体前缘变形显著增加并向坡体中部逐渐扩大阶段、滑坡体后缘加速变形阶段3个阶段;滑坡体上InSAR监测点垂直方向的形变速率及累积变形数据显示坡体前缘及中部形变速率和累计变形较小,变形主要集中在滑坡体的后缘,其形变速率和累计沉降最大分别可达40 mm/a和320 mm,该滑坡为推移式滑坡。研究结果为滑坡的早期识别及监测预警提供了新的思路和方法,对滑坡灾害的防治有一定的参考价值。

Landslides induced by typhoon rainstorm has the characteristics of abruptness and difficulty in the investigation.Taking the Shanzao landslide that occurred during the typhoon"Lekima"as an example,based on 24 landscape data of Railway Sentinel-1 from Sept.12,2017,to Aug.9,2019,this paper analyzed the sequential cumulative deformation of landslides in this period by SBAS-InSAR technology and further analyzed the regularity of surface deformation of landslide mass with meteorological data.The results show that the deformation before the occurrence of Shanzao landslide is mainly divided into three stages:creep stage of landslide mass,deformation of front edge of landslide mass increases significantly and gradually expands toward the middle of the slope mass,and accelerated deformation stage of the rear edge of landslide mass.The vertical deformation rate and accumulated deformation data of InSAR monitoring points on the landslide mass show that the deformation rate and accumulated deformation in the front and middle of slope are small,and it mainly focus on the rear edge of the landslide,with the maximum deformation rate and accumulated settlement of 40 mm/a and 320 mm respectively.The landslide is a push-over landslide.The research results provide a new idea and method for the early identification,monitoring and early warning of landslides,and have a certain reference value for the prevention and control of landslide disasters.