Monitoring Land Subsidence in Fuzhou City (China) Using the SBAS-InSAR Method with Sentinel-1 Imagery Data

Fuzhou is the capital city of Fujian Province. In recent years, the city has developed rapidly and the traffic network has become increasingly complete. Due to the construction of high-intensity cities and the construction and operation of underground projects (such as subways), the problem of land subsidence has become increasingly prominent. In this paper, using SBAS-InSAR technology to extract land subsidence information from Fuzhou based on Sentinel-1A data from 2018 to 2019. The results shown that there are 7 major subsidence areas monitored in Fuzhou, and the average subsidence rate varies from -82 to 44 millimeters per year (mm/yr). Among them, 4 obvious subsidence are located in Fuzhou Metro Line 1 and Line 2 surroundings. Land subsidence is caused by the combination of natural and human factors. The natural condition is the basis of subsidence, making subsidence possible; and human activity is the main driving force for the subsidence. As time goes by, the subsidence becomes more series. Further monitoring of urban subsidence is necessary in the future.