Evidence of subsidence control in Shanghai revealed by 10 Years of InSAR observations

Since 2006, Shanghai has implemented a comprehensive subsidence control system, which aimed at groundwater extraction restrictions, artificial recharge, and the control of engineering-based settlement. While significant results have been achieved, a systematic scientific evaluation of its specific effectiveness remains unclear. This study utilizes Sentinel-1 SAR data from 2015–2024 and employs SBAS-InSAR technology to obtain high-precision ground deformation fields across Shanghai. A Multilayer Perceptron (MLP) model was introduced to intelligently classify time-series deformation data, through which we identified five typical patterns: rapid subsidence, minor subsidence, fluctuating deformation, periodic deformation, and uplift. Building upon this foundation, the research integrates Shanghai’s subsidence control zoning data and four-phase land use data (1990, 2000, 2015, 2022) to systematically evaluate the regional effectiveness of subsidence control policies and reveal the driving mechanisms of different deformation patterns from a land use transition perspective. Results demonstrate that the stratified subsidence control policy has achieved significant results with distinct spatial differentiation characteristics: major prevention zones exhibit stable deformation (benign patterns reaching 72.03%), while general prevention zones display high-risk, highly dynamic characteristics (benign patterns accounting for only 29.73%). Further analysis reveals strong coupling between the five deformation patterns and land use history: rapid subsidence concentrates in historical reclamation areas, and uplift correlates with active intervention measures. These findings confirm that subsidence control effectiveness is closely associated with regional “land use background” and “development stage.” This study provides a scientific basis for optimizing precision governance strategies in Shanghai and offers a valuable reference framework and methodology for other coastal megacities worldwide facing similar challenges.