Characterization of Deformation Driven by the South-to-North Water Diversion and Extreme Rainfall Along the Taihang Piedmont Using Time-Series InSAR

Long-term groundwater overexploitation in the North China Plain has triggered severe land subsidence. Meanwhile, the implementation of the Middle Route of the South-to-North Water Diversion (SNWD) project and extreme precipitation events driven by climate change are exerting profound impacts on the regional hydrogeological environment. However, the localized deformation response mechanisms at a sub-kilometer to kilometer scale under the combined influence of large-scale hydraulic engineering and extreme weather events remain unclear. In this study, we utilized ascending Sentinel-1A SAR data from 2017 to 2025. By employing the Small Baseline Subset InSAR (SBAS-InSAR) technique, coupled with the Generic Atmospheric Correction Online Service (GACOS) and multi-track mosaicking, we acquired high-spatiotemporal-resolution vertical land deformation fields in the piedmont of the Taihang Mountains (Northern Henan to Southern Hebei section). Furthermore, we analyzed these deformation fields by integrating deformation pattern classification with the spatial distribution of geological structures and water diversion projects. Through this approach, we explored the controlling factors and impacts of heavy rainfall events and the SNWD project on regional land deformation.