Monitoring Land Subsidence at San Francisco International Airport Using Satellite Radar Interferometry

Abstract. Coastal airports are increasingly vulnerable to infrastructure degradation from land subsidence exacerbated by sea-level rise (SLR) and extreme weather events. San Francisco International Airport (SFO), situated on a reclaimed land overlying thick compressible Young Bay Mud, provides a representative case study for understanding the implications of land subsidence on infrastructure resilience. This study employs advanced Interferometric Synthetic Aperture Radar (InSAR) techniques to measure and analyze spatially detailed subsidence at SFO from 2017 to 2024. We integrate the InSAR data with subsurface stratigraphy derived from geotechnical investigations and historical construction records to identify and quantify patterns and drivers of subsidence. The results indicate spatially heterogeneous subsidence rates, with rates exceeding −10.0 ± 0.1 mm/yr, concentrated primarily under the airfield's infrastructure, notably along Runway 10R/28L. Temporal analyses of deformation time series reveal significant variability and nonlinear trends, likely due to seasonal groundwater fluctuations, construction activities, and heterogeneous subsurface stratigraphy. Areas with older hydraulically placed fills demonstrate higher rates of long-term compaction, emphasizing the critical role of historical construction practices and sediment properties. This study's findings underscore the urgent need for comprehensive and continuous ground deformation monitoring at coastal airports. The implications for infrastructure resilience planning at SFO serve as a valuable model for other coastal airports facing similar geotechnical and climatic challenges.