基于小基线集干涉测量的天津地区地表沉降时空分析

Spatial-temporal Analysis of Surface Subsidence in Tianjin Area Based on SBAS-InSAR

基于覆盖天津地区2017—2019年的30景Sentinel-1A影像数据,采用小基线集合成孔径雷达干涉测量(small baseline subset interferometric synthetic aperture radar,SBAS-InSAR)方法对研究区域进行地表沉降监测,获取了天津地区的年平均沉降速率和累积沉降,并与水准数据进行比对,最后分析了该地区的沉降时空特征。结果表明:2017—2019年大部分区域地表形变速率为-15.8~4.1 mm/a,最大沉降速率超过-130 mm/a,最大沉降中心位于天津市西青区王庆坨镇;基于SBAS-InSAR获取的沉降结果与水准测量结果比对,其精度达到2.96 mm;地表沉降受地下水开采、城市基础建设的发展以及工业用地量、人为活动等方面因素影响明显。

Based on 36 scenes of Sentinel-1 A image data covering the Tianjin area from 2017 to 2019, the small baseline subset interferometric synthetic aperture radar(SBAS-InSAR) method was used to study the land subsidence monitoring area and determine the annual average settlement rate and cumulative settlement in Tianjin area. The SBAS-InSAR derived results were compared with the leveling data. Finally, the spatial-temporal characteristics of subsidence in the region were analyzed. Results show that most of the regional surface deformation rate is in the range of-15.8 to 4.1 mm/a from 2017 to 2019, and the maximum subsidence rate is more than-130 mm/a;the largest settlement center was located in the town of Wang Qingtuo, Xiqing District, Tianjin. The settlement data obtained by SBAS-InSAR are compared with the level measurement results, and the accuracy reaches 2.96 mm. The surface subsidence was obviously affected by factors such as groundwater exploitation, urban infrastructure development, industrial land use, and human activities.