InSAR-derived land subsidence in Wuhan between 2015 and 2020

Abstract

Land subsidence has become a challenging problem with urbanization and underground exploitation. The land subsidence in Wuhan, China, was inferred from 47 Sentinel-1A images acquired between June 2015 to October 2020 based on Synthetic Aperture Radar (SAR) Interferometric Point Target Analysis (IPTA) technology. Results show that significant subsidence mainly occurred in Houhu, Qinshan, Baishazhou, and Zhuankou areas, and the most significant subsidence occurred in Baishazhou, reaching an annual subsidence rate of 41.0 mm/a with accumulated subsidence of 219.4 mm., The subsidence was more significant in the carbonate solution zone with the overlying Holocene strata compared to the rest carbonate karst belts. Analysis shows thatland building construction is a major reason for land subsidence in Wuhan. The construction of subway underground stations is another factor causing land subsidence. The effect of water level fluctuations of the Yangtze River on long-term trends is negligible. Our study provides further insight into the temporal-spatial pattern of Wuhan’s displacements and suggests that the land subsidence should be continuously monitored for alleviation of potential destructive hazards, especially during the period of construction of a land building, such as residential, public facilities, and subway.