Characterization and causes of land subsidence in Beijing, China
Characterization and causes of land subsidence in Beijing, China
复制标题
北京地面沉降特征及成因
DOI：
10.1080/01431161.2016.1259674
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发表时间：
2017-01-01
影响因子：
3.4
通讯作者：
Zhou, Chaofan
中科院分区：
文献类型：
--
作者：
Chen, Beibei;Gong, Huili;Zhou, Chaofan
北京平原区地下水长期超采是造成区域地面沉降的主要原因。目前，北京南部和北方各有一个大的沉降漏斗。采用多时相干涉合成孔径雷达（MT-InSAR）方法，对47幅Envisat高级合成孔径雷达（ASAR）单视复相（SLC）图像进行持续散射体（PS）和小基线（SB）相结合的方法，对北京平原地区地面沉降进行了研究。MT-InSAR结果解释了地面沉降的时空变化和季节变化。然后，将干涉合成孔径雷达成果与地下水位动态监测、伸缩仪测量、水文地质资料相结合，利用地理信息系统（GIS）空间分析方法，对地面沉降特征及成因进行分析。结果表明：1)2003 - 2010年北京平原地区地面沉降发展迅速，不均匀沉降明显，部分地区沉降速率超过100 mm a-1。沉降率的季节性变化可能受到降水率变化和地下水开采的影响。2)不同含水层系统对地面沉降的贡献不同。第二承压含水层100-180 m深度的地下水位变化对地面沉降的影响最大。3)沉降集中在温榆河潮白冲积扇和永定冲积扇下部，压缩层厚度超过100 m。同时，地面沉降形成了断层两侧变形梯度差异较大的构造特征。
ABSTRACT Long-term overexploitation of groundwater is the primary factor causing regional land subsidence in the Beijing plain area, China. Currently, large subsidence funnels exist, one each in southern and northern Beijing. We adopted the multi-temporal interferometric synthetic aperture radar (MT-InSAR) method, incorporating both persistent scatterer (PS) and small baseline (SB) approaches on 47 Envisat Advanced Synthetic Aperture Radar (ASAR) single look complex (SLC) images to map land subsidence in the Beijing plain area. The temporal and spatial variations of land subsidence and its seasonal variation were explained by the MT-InSAR results. Then, the InSAR results were combined with the dynamic monitoring of groundwater level, extensometer measurements, and hydrogeological data; the characterization and causes of land subsidence were analysed with Geographic Information System (GIS) spatial analysis methods. The results show the following. 1) Land subsidence developed rapidly in the Beijing plain area from 2003 to 2010, with obviously uneven settlement; settlement rates exceeded 100 mm year−1 in some areas. Seasonal variation in settlement rates may be affected by changes in the precipitation rates and the exploitation of groundwater. 2) The contribution of different aquifer systems to land subsidence varies. The variation in the groundwater level in the second confined aquifer, at a depth of 100–180 m, has the greatest impact on land subsidence. 3) The settlement is centred in the lower part of the Wenyu–Chaobai and Yongding alluvial fan areas, where the compressible layer is more than 100 m thick. Meanwhile, land subsidence forms a structural feature with larger differences in the deformation gradient on both sides of faults.