基于时序InSAR技术的滨海新区地面沉降监测

Land subsidence monitoring in Binhai New Area based on time-series InSAR technology

针对传统地面沉降测量方法在大范围测区内费时长、时效性差等缺点,本文利用2017—2021年覆盖天津市滨海新区Sentinel-1A影像数据,采用永久散射体合成孔径雷达干涉测量(PS-InSAR)和短基线集合成孔径雷达干涉测量(SBAS-InSAR)技术获取地面沉降数据,通过地表形变信息的时空分析确定各类因素对地面沉降的影响并交叉验证结果的可靠性。分析结果表明,天津市滨海新区的地面沉降受到降水、第四系地层厚度、地下水等因素影响。其中,天津市滨海新区在2017—2021年存在地面沉降现象,最大沉降速率为-130 mm/a,最大抬升速率为40 mm/a,最大累计沉降量为-411 mm。重点沉降区域主要分布在东北部的杨家泊镇与寨上街道交界地区以及西南部的中塘镇和北大港水库附近。

In view of the shortcomings of traditional land subsidence measurement methods such as long time consumption and poor timeliness in a wide range of measurement areas,this paper used Sentinel-1A image data covering Binhai New Area in Tianjin from 2017 to 2021 and adopted persistent scatterer interferometric synthetic aperture radar(PS-InSAR)and small baseline subset interferometric synthetic aperture radar(SBAS-InSAR)to obtain land subsidence data.The spatio-temporal analysis of land surface deformation information determined the influence of various factors on land subsidence,and the reliability of the results was cross-verified.The analysis results show that the land subsidence in Binhai New Area in Tianjin is affected by precipitation,quaternary strata thickness,groundwater,and other factors.Among them,there is land subsidence in Binhai New Area in Tianjin from 2017 to 2021,with a maximum subsidence rate of−130 mm/a,a maximum lifting rate of 40 mm/a,and a maximum cumulative subsidence of−411 mm.The key subsidence areas are mainly distributed in the junction area of Yangjiabo Town and Zhaishang Street in the northeast and near Zhongtang Town and Beidagang Reservoir in the southwest.