基于时序InSAR的沿江地面形变监测与精度分析

Monitoring and accuracy analysis of ground deformation along the Yangtze River based on time-series InSAR

针对长江两岸部分城市区域出现的地面沉降问题,提取2018年1月至2023年4月覆盖长江沿线南京-马鞍山段部分区域的60余景Sentinel-1A SAR影像,结合高精度PS特征点和SBAS-InSAR技术,监测该区域的地表形变情况。融入PS点的SBAS-InSAR技术与常规SBAS-InSAR技术结果均与水准测量结果高度一致,前者一致性和精度更高,相关决定系数高达0.91。实验发现该区域有3个典型沉降漏斗,分布在南京浦口区长江沿岸、建邺区东北部与秦淮区西北部交界处以及江宁区与安徽马鞍山市交界处,该区域沉降的主要原因地层岩性及新构造运动、工程活动、地下水位变化等。文中研究结果表明,融入PS点的SBAS-InSAR技术既可以获取高精度的地面形变结果,又可以为相关部门进行灾害风险管理和城市规划提供一定的技术支持。

In response to the land subsidence problem in some urban areas along Yangtze River,more than 60 Sentinel-1A SAR images covering the areas of Nanjing and Ma’anshan from January 2018 to April 2023 were extracted.By combining high-precision PS feature points and SBAS-InSAR technology,the ground deformation situation in the area was monitored.The results of SBAS-InSAR technology integrated with PS points and conventional SBAS-InSAR technology were highly consistent with leveling results.The former has higher consistency and accuracy,with a correlation coefficient of up to 0.91.The experiment found three typical subsidence funnels in this area,which distributed along the Yangtze River in Pukou District,at the junction of northeast of Jianye District and northwest of Qinhuai District,and at the junction of Jiangning District and Ma’anshan City in Anhui.The main causes of subsidence in this area include stratigraphic lithology,neotectonic movement,engineering activities,and changes in groundwater level.The results demonstrate that the SBAS-InSAR technology integrated with PS points can obtain high-precision ground deformation results,which can provide certain technical support for relevant departments in disaster risk management and urban planning.