Spatiotemporal characteristics of land subsidence in Beijing from small baseline subset interferometric synthetic aperture radar and standard deviational ellipse

Land subsidence in Beijing has occurred since the 1970s. Five major subsidence areas have formed: Dongjiao Ba Lizhuang-Da Jiaoting, Dong Beijiao-Lai Guangying, Changping Shahe-Ba Xianzhuang, Daxing Yufa-Lixian, and Shunyi-Ping Gezhuang. In this study, we investigated Chaoyang, Shunyi, and Tongzhou districts, which have experienced relatively serious subsidence, and obtained land subsidence monitoring results using data from 47 ASAR images obtained between 2004 and 2010 and the small baseline subset interferometric synthetic aperture radar (SBAS InSAR). On this basis, we calculated the spatial distribution center of persistent scatterer points and the eigenellipse to analyze the spatiotemporal characteristics of subsidence in the study area.