利用时序InSAR监测兰州市中心城区地面沉降

Surface subsidence monitoring of Lanzhou downtown area based on time series InSAR technology

针对兰州市中心城区的地面沉降问题,该文采用PS-SBAS和PS-InSAR技术,利用2016-01-20—2019-02-21时间段内的39景Sentinel-1A/B降轨数据,使用缓冲区分析技术对兰州市中心城区轨道交通线和铁路线周边100m区域做了沉降影响分析,监测结果表明:基于Sentinel-1A/B数据和时序InSAR技术,可以准确监测城市地表的沉降和轨道交通线的沉降时空规律;沉降区域主要集中在研究区东南部的方家泉村、和平镇和猪咀岭村;软土地基下地铁的施工会导致沉降现象的发生,兰州轨道交通线和铁路线的沉降主要发生在城区东南方向;在监测时段内,使用两种时序InSAR技术监测的同名点在沉降趋势和累计沉降量上保持了良好的一致性和吻合性,但PS-InSAR的时序变化曲线较PS-SBAS更为平缓。

Aiming at the land subsidence in the downtown area of Lanzhou City,based on the Sentinel-1A/B rail descending data of 39scenes from January 20,2016to February 21,2019,PS-SBAS and PS-InSAR technologies were adopted to analyze the impact of subsidence on the rail transit line and 100marea around the railway line in the downtown area of Lanzhou City by using the buffer zone analysis technology.The monitoring results showed that,based on Sentinel-1A/B data and time-series InSAR technology,the subsidence of land surface and the subsidence of rail transit lines at the urban scale could be accurately monitored.and the subsidence area was mainly concentrated in Fangjiaquan Village,Heping Town and Zhuzuiling Village in the southeast of the study area.The construction of the subway under the soft soil foundation would lead to the occurrence of subsidence,the subsidence of the rail transit line and railway line in Lanzhou City during the monitoring period was mainly in the southeast direction of the downtown area of Lanzhou City.During the monitoring period,the correspondence points monitored by the two time-series InSAR technologies maintained a good consistency and agreement in the subsidence trend and accumulated subsidence,but the time-series variation curve of PS-InSAR was gentler than that of PS-SBAS.