Recent subsidence in Tianjin, China: observations from multi-looking TerraSAR-X InSAR from 2009 to 2013
Recent subsidence in Tianjin, China: observations from multi-looking TerraSAR-X InSAR from 2009 to 2013
复制标题
中国天津最近的沉降：2009 年至 2013 年多视 TerraSAR-X InSAR 观测
DOI：
10.1080/01431161.2015.1109729
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发表时间：
2015
影响因子：
3.4
通讯作者：
Zhang YH
中科院分区：
文献类型：
--
作者：
Zhu Chuanguang;Zhang Liya;Long Sichun;Zhu Chuanguang;Zhang Yonghong;Zhang Jixian;Wu Hongan;Zhang YH
有人指出，中国天津由于过度开采地下水，地面沉降严重。监测这种下沉是必要的，它具有潜在的危害和风险。时间序列InSAR (TS-InSAR)，如小基线子集（SBAS），是一种能够长时间高精度、高空间分辨率监测地面变形的强大工具。然而，当使用高空间分辨率SAR（如TerraSAR-X、TSX）图像时，计算复杂度可能会超过计算机内存限制。本文将多视角方法引入stamp /MTI （Stanford method for persistent scatter/multi-temporal InSAR）的SBAS工具中，以平衡探测中的空间分辨率和沉降信息。用于多视的外观首先根据变形的精度和相干点的密度来确定。然后，基于2009 - 2013年采集的48幅TSX图像，采用多视SBAS提取天津地区近期沉降。结果通过平整测量得到验证，其均方根误差（RMSE）为4.7 mm - 1，这表明SBAS分析可以有效地监测调查区域基于多视角TSX采集的变形。此外，研究结果还表明，天津在此期间一直遭受沉降，研究区内存在两个独立的大型沉降盆地，累积沉降量大于500 mm。而且，2010年12月以后，天津的沉降速率有所增加。
Tianjin, China, has been suggested to have serious ground subsidence due to excessive extraction of groundwater. It is essential to monitor this subsidence, which has potential hazards and risks. Time series InSAR (TS-InSAR), such as small baselines subset (SBAS), is a powerful tool that can monitor ground deformation with high accuracy and at high spatial resolution over a long time interval. However, the high computational complexity may exceed computer memory limit when high-spatial resolution SAR (such as TerraSAR-X, TSX) images are used. In this article, the multi-look approach is introduced to the SBAS tool from StaMPS/MTI (Stanford method for persistent scatter/multi-temporal InSAR) in order to balance the spatial resolution and subsidence information in detection. The looks used for multi-looking are first fixed in terms of the accuracy of deformation and the density of coherent points. Then, the recent subsidence in Tianjin is extracted using multi-looking SBAS based on 48 TSX images acquired from 2009 to 2013. The results are validated by levelling measurements with a root mean square error (RMSE) of 4.7 mm year–1, which demonstrates that SBAS analysis can effectively monitor deformation based on multi-looking TSX acquisitions in the area under investigation. Besides, the results also show that Tianjin has been suffering from subsidence during this period, and there were two separate large subsidence basins located in this study area with more than 500 mm cumulative subsidence. Moreover, the subsidence rate increased after December 2010 in Tianjin.