Monitoring Land Surface Displacement over Xuzhou (China) in 2015-2018 through PCA-Based Correction Applied to SAR Interferometry
Monitoring Land Surface Displacement over Xuzhou (China) in 2015-2018 through PCA-Based Correction Applied to SAR Interferometry
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DOI：
10.3390/rs11121494
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发表时间：
2019-06
期刊：
影响因子：
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通讯作者：
Yu Chen;Kun Tan;Shiyong Yan;Kefei Zhang;Hairong Zhang;Xiaoyang Liu;Huaizhan Li;Yaqin Sun
中科院分区：
文献类型：
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作者：
Yu Chen;Kun Tan;Shiyong Yan;Kefei Zhang;Hairong Zhang;Xiaoyang Liu;Huaizhan Li;Yaqin Sun
大都市地区的地表变形对人类生命和财产造成不同程度的危害，几十年来在世界各地的城市中已有记录。徐州是中国东部最重要的能源和工业基地之一，近几十年来，由于过度开采岩溶地下水和开采矿产资源，导致了严重的地面沉降。此外，徐州最近经历了快速的城市化，城市扩张和地下建设，这可能会对城市土地表面造成额外的压力。然而，以往的研究大多是基于传统的地面变形监测技术与稀疏测量在徐州城市地区的地表变形。徐州地区陆面位移的区域性时空变化特征尚不清楚。利用干涉合成孔径雷达（干涉合成孔径雷达）时间序列分析方法，研究了徐州市中心地区2015-2018年地表形变的空间格局和时间演变特征。采用基于主成分分析的方法对干涉合成孔径雷达信号中的伪影进行校正。结果表明，该校正策略明显减小了全球导航卫星系统与干涉合成孔径雷达测量值之间的差异。徐州城区范围内普遍出现明显的地面沉降（-5至-41毫米/年），特别是沿着在建地铁线路、新开发区和老煤矿采空区。自2015年以来，发现显著一致的陆地隆起（高达+25 mm/年）对老采空区内的两个狭长区域产生了显著影响。讨论了地铁隧道、建筑物施工、采矿、地下水位和地质条件等可能影响地表位移的主要因素。
Land surface deformation in metropolitan areas, which can cause varying degrees of hazard to both human lives and to properties, has been documented for decades in cities worldwide. Xuzhou, is one of the most important energy and industrial bases in eastern China, and has experienced significant land subsidence due to both excessive extraction of karst underground water and exploitation of mineral resources in recent decades. Furthermore, Xuzhou has recently undergone rapid urbanization in terms of urban expansion and underground construction, which could induce additional pressure on the urban land surface. However, most previous research on land surface deformation in the Xuzhou urban areas has been conducted based on traditional ground-based deformation monitoring techniques with sparse measurements. Little is known about the regional spatiotemporal behavior of land surface displacement in Xuzhou. In this study, a detailed interferometric synthetic aperture radar (InSAR) time series analysis was performed to characterize the spatial pattern and temporal evolution of land surface deformation in central areas of Xuzhou during 2015–2018. A method based on principal component analysis was adopted to correct artifacts in the InSAR signal. Results showed the correction strategy markedly reduced the discrepancy between global navigation satellite systems and InSAR measurements. Noticeable land subsidence (−5 to −41 mm/yr) was revealed widely within the Xuzhou urban areas, particularly along subway lines under construction, newly developed districts, and in old coal goafs. Remarkable consistent land uplift (up to +25 mm/yr) was found to have significantly affected two long narrow areas within the old goafs since 2015. The possible principal influencing factors contributing to the land surface displacements such as subway tunneling, building construction, mining, underground water levels and geological conditions are then discussed.