Long-time surface deformation in Beijing, China for three decades by multi-sensor, multi-track and multi-temporal InSAR seamless connection

Due to excessive groundwater exploitation, the Beijing Plain (BJP) has experienced severe land subsidence for decades, threatening infrastructure. In this article, a multi-sensor, multi-track and multi-temporal SAR interferometry data seamless connection algorithm (termed by 3MSC-InSAR algorithm) is proposed, and applied to C-band ERS (1992-2003) and ENVISAT (2003-2010) datasets in descending track, as well as X-Band TerraSAR-X (2010-2015) and C-Band Sentinel-1 (2015-2022) datasets in ascending track to achieve a seamless connection and spatiotemporal benchmark unification of InSAR deformation monitoring in the BJP for 30 years. Validated by GNSS data, the algorithm shows high accuracy (RMSEs: 6.2 mm, 4.8 mm, 11.7 mm). The BJP exhibited multiple settlement funnel centers, with a maximum deformation of 1.5 m. Independent Component Analysis (ICA) identified three spatiotemporal components: S-type (IC1), acceleration (IC2), and rebound (IC3). IC1 reflected the full subsidence cycle, including slow, accelerated, and mitigated phases. From 1992 to 2015, subsidence was driven by geological factors, water supply, and excessive groundwater extraction. After 2015, subsidence reduction and local rebound occurred due to Beijing’s groundwater exploitation ban and the South-to-North Water Diversion Project, which replenished deep groundwater levels. This study highlights the dual influence of human activities and natural factors on land subsidence evolution.