Spatiotemporal evolution of land subsidence around a subway using InSAR time-series and the entropy method |
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Authors: | Wen-Feng Chen Hui-Li Gong Kai-Si Liu Mingliang Gao Chao-Fan Zhou |
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Affiliation: | 1. Base of the State Key Laboratory of Urban Environmental Process and Digital Modeling, Capital Normal University, Beijing, China;2. Key Laboratory of 3D Information Acquisition and Application of Ministry of Education, Capital Normal University, Beijing, China;3. Beijing Laboratory of Water Resources Safety, Capital Normal University, Beijing, China;4. College of Resource Environment and Tourism, Capital Normal University, Beijing, China;5. Key Laboratory of Resources Environment and GIS of Beijing Municipal, Capital Normal University, Beijing, China |
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Abstract: | The underground railway network of Beijing City, China, which is an important urban infrastructure, has burgeoned with the expansion of the city. However, the influence of subway construction and operation on local subsidence has received minimal attention. By analyzing the Radarsat-2 synthetic aperture radar satellite data, and using persistent scatterer interferometry, we revealed the land subsidence characteristics along the Beijing Subway Line 6. In the context of land subsidence, the expectation (Ex) reflects the overall level of local land subsidence while the entropy (En) reflects the degree of nonuniformity of local land subsidence in time and space. By comparing the changes in Ex and En, we estimated the spatial range of the influence of the subway on local land subsidence. The influenced area was mainly located between 60 m north of the subway line and 80 m south of the subway line. Land subsidence was most strongly altered during subway construction. During operation of the subway, the deformation rates along the subway increased slightly in the first two years and were then stabilized. |
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Keywords: | subway land subsidence entropy InSAR GIS |
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