Title: Monitoring Land Subsidence in Wuhan City (China) using the SBAS-InSAR Method with Radarsat-2 Imagery Data

Authors: Zhang, Y (Zhang, Yang); Liu, YL (Liu, Yaolin); Jin, MQ (Jin, Manqi); Jing, Y (Jing, Ying); Liu, Y (Liu, Yi); Liu, YF (Liu, Yanfang); Sun, W (Sun, Wei); Wei, JQ (Wei, Junqing); Chen, Y (Chen, Yiyun)

Source: SENSORS Volume: 19 DOI: 10.3390/s19030743 published: FEB 2019

Abstract: Wuhan city is the biggest city in central China and has suffered subsidence problems in recent years because of its rapid urban construction. However, longtime and wide range monitoring of land subsidence is lacking. The causes of subsidence also require further study, such as natural conditions and human activities. We use small baseline subset (SBAS) interferometric synthetic aperture radar (InSAR) method and high-resolution RADARSAT-2 images acquired between 2015 and 2018 to derive subsidence. The SBAS-InSAR results are validated by 56 leveling benchmarks where two readings of elevation were recorded. Two natural factors (carbonate rock and soft soils) and three human factors (groundwater exploitation, subway excavation and urban construction) are investigated for their relationships with land subsidence. Results show that four major areas of subsidence are detected and the subsidence rate varies from -51.56 to 27.80 millimeters per year (mm/yr) with an average of -0.03 mm/yr. More than 83.81% of persistent scattered (PS) points obtain a standard deviation of less than -6 mm/yr, and the difference between SBAS-InSAR method and leveling data is less than 5 mm/yr. Thus, we conclude that SBAS-InSAR method with Radarsat-2 data is reliable for longtime monitoring of land subsidence covering a large area in Wuhan city. In addition, land subsidence is caused by a combination of natural conditions and human activities. Natural conditions provide a basis for subsidence and make subsidence possible. Human activities are driving factors and make subsidence happen. Moreover, subsidence information could be used in disaster prevention, urban planning, and hydrological modeling.

Document Type: Article

Language: English

Authors’ key words: land subsidence; Radarsat-2 images; small baseline subset (SBAS) method; interferometric synthetic aperture radar (InSAR)

Keywords plus: Groud Deformation; Beijing Plain; Sentinel-1; interferometry; exploitation; Shanghai; Impacts; Cities

Addresses of reprint authors:

[Liu, YF; Chen, Y]Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China

E-mail: zhangy1010@whu.edu.cn; liuyaolin2010@163.com; kingerin@163.com; y.crystal@whu.edu.cn; liuyi2010@whu.edu.cn; yfliu59@126.com; gnss.wei@gmail.com; weijunqing@whu.edu.cn; chenyy@whu.edu.cn

Addresses:

[Zhang, Yang; Liu, Yaolin; Jin, Manqi; Jing, Ying; Liu, Yi; Liu, Yanfang; Wei, Junqing; Chen, Yiyun] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China

[Liu, Yaolin] Wuhan Univ, Key Lab Geog Informat Syst, Minist Educ, Wuhan 430079, Hubei, Peoples R China

[Liu, Yaolin] Collaborat Innovat Ctr Geospatial Informat Techno, Wuhan 430079, Hubei, Peoples R China

[Sun, Wei] Wuhan Geomat Inst, Wuhan 430022, Hubei, Peoples R China

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