Differential land deformation patterns and response mechanism to groundwater recovery in the Beijing-Tianjin-Hebei Plain revealed by reconstructing and clustering of TS-InSAR observations

• Reconstructed seasonal and long-term components from mosaicked TS-InSAR deformation. • Identified differential deformation patterns using characteristic-constrained K-means. • Uncertainty reflects short-term fluctuations from extreme climate and human activities. • Revealed multi-scale responses of differential deformation patterns to GWL changes. The Beijing-Tianjin-Hebei (BTH) Plain in north China has experienced significant land subsidence due to long-term groundwater overexploitation. Although water diversion project and climate change have improved groundwater conditions overall, the spatiotemporal heterogeneity in land deformation responses to groundwater recovery remains unclear. This study reconstructs and identifies differentiated deformation patterns across the BTH Plain under the new hydrological background, revealing their multi-scale response mechanisms to groundwater change. After mosaicking Time-Series Interferometric Synthetic Aperture Radar (TS-InSAR) deformation fields, we reconstructed the seasonal and long-term components of deformation. A long-term deformation characteristic-constrained K-means clustering method was developed to classify distinct deformation evolution patterns. Coupling these patterns with groundwater-level (GWL) observations to further distinguish the annual lag and long-term delayed response of deformation to GWL changes. From 2016 to 2024, the BTH Plain exhibits clear spatial partitioning of deformation behaviors, categorized as 10.14% continuous subsidence, 18.86% reduced subsidence, 46.09% stable deformation, and 24.91% slight rebound. Uncertainties in the reconstructed deformation reflect short-term fluctuations driven by extreme hydrological or anthropogenic disturbances. Short-time Fourier transform analysis reveals periodic response of deformation to GWL change and annual lag: elastic deformation dominated areas lag GWL by ≤ 2 months, whereas clay-rich persistent subsiding areas lag 4–6 months. The exponential decay model further indicates that the recovery of subsidence funnels is governed by geological structures: funnels intersecting faults show the slowest subsidence decay along their edges, while those without faults display a more uniform edge-to-center recovery pattern.