基于高分辨率SAR影像的上海临港新城沉降格局分析

The analysis of the subsidence patterns in Lingang New City(Shanghai) using high-resolution SAR images

上海临港新城是通过围垦造地工程建设而成,特殊的地质条件和地理位置,使其地质环境变化备受关注。而建立和完善该新城的水准测量网需要一定时间,且基于点的水准监测难以获得区域沉降情况。时间序列InSAR方法可通过空间信息实施大范围监测,对于此类海塘新区的地面沉降监测具有独特优势。本文处理和分析了11景TerraSAR-X影像,并与之前的研究成果进行分析。实验结果表明,临港新城的沉降情况与围垦成陆的建设施工时序密切相关,九四塘以西的老冲填土区已趋于稳定,并有回弹趋势;九四塘以东的新冲填土区形变量较大,沉降速率近35mm/a。利用14个水准点的监测数据进行验证,其平均误差为1.510mm、中误差为2.016,说明该方法可以满足城市形变监测的需求。

Lingang New City in Shanghai was built on land reclaimed ~om the sea, and the associated changes in the geological environment required considerable attention due to the special nature of the geological conditions and geographic location. In such a setting, monitoring land levels is difficult, and obtaining regional subsidence information is time consuming. However, the large-scale monitoring time series derived from InSAR measurements offers unique advantages in these situations. In this paper, analysis of InSAR time series was used to investigate ground deformation in Lingang New City using 11 TerraSAR-X images acquired between 2009 and 2010, and the results of this study were compared with previous research. The results demonstrate that, dunng this period, subsidence in Lingang New City was closely related to the sequence of construction works. The areas of former hydraulic fill soil become stable and even rebounded, while the new hydraulic fill soils showed greater deformation, with an average subsidence rate of 35 mm/year. These results have been validated by monitoring data ~om 14 leveling points provided by the Shanghai Institute of Geological Survey, and the average error was 1.510 mm, while the mean square error was 2.016, which means that the results of the time sedes analysis meet the demands of the city with regard to deformation monitonng.