基于小基线集干涉测量的天津地区地表沉降时空分析

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。

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

In this paper, based on 36 scenes of Sentinel-1A image data covering the Tianjin area from 2017 to 2019,we used SBAS-InSAR method to study land subsidence monitoring area and achieve the annual average settlement rate and cumulative settlement Tianjin area. The SBAS-InSAR derived results were compared with leveling data. Finally, the spatial-temporal characteristics of subsidence in the region was analyzed. The results show that most of the regional surface deformation rate is in the range of -15 to 13 mm / a from 2017 to 2019,and the maximum subsidence rate of more than -130 mm/a,the largest settlement center is located in the town of wang qingtuo, xiqing district, Tianjin; the settlement results obtained based on SBAS-InSAR are compared with the level measurement results, and the accuracy reaches 2.96 mm; surface subsidence is obviously affected by factors such as groundwater exploitation, urban infrastructure development, industrial land use, and human activities.