Impacts of ecological water replenishment on groundwater dynamics and urban safety: Insights from ground deformation in Beijing Yongding River area, China

Study Region This study investigates spatiotemporal dynamics and environmental impacts in the Yongding River Basin through a comprehensive analysis of ecological water replenishment (EWR) interventions. Study Focus Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR), Seasonal-Trend decomposition based on Loess (STL), and wavelet transform. The research examines the interconnections between ecological water management strategies, surface deformation patterns, land subsidence evolution, and groundwater dynamics.The findings provide insights for optimizing water replenishment strategies, advocating for integrated monitoring frameworks. These outcomes underscore the imperative of predictive hydrogeological modeling in sustainable basin management and climate-resilient infrastructure planning. New Hydrological Insights for the Region First, pronounced subsidence was identified in the eastern downstream region of the Beijing section. The synergistic effects of EWR and ongoing subsidence amplify risks to subsurface infrastructure integrity. These compounding factors pose significant threats to transportation infrastructure, necessitating prioritized monitoring. Second, the subsidence exhibits marked spatiotemporal heterogeneity and nonlinear response characteristics, suggesting temporally variable interactions between geological processes, anthropogenic activities, and hydrological modifications. Third, while current EWR operations have not yet induced substantial deformation, predictive simulations indicate a critical threshold scenario: A sustained groundwater level rise of 2.74 m/yr would submerge building foundations in sensitive zones (e.g., T-5 sector) within five years. This research advances understanding of coupled hydrogeological-engineering systems in managed river basins, demonstrating that groundwater rebound from EWR may paradoxically threaten infrastructure stability.