The Ganges-Brahmaputra Delta (GBD) of Bangladesh is one of the most densely populated and environmentally vulnerable regions in the world, facing the combined threats of sea level rise and land subsidence. Previous studies have documented a complex spatial and temporal pattern of subsidence in the GBD, driven by a range of natural and anthropogenic processes. However, a comprehensive, high-resolution understanding of subsidence across the delta remains elusive. This research proposal aims to integrate newly acquired high-resolution digital surface models (DSMs) and Differential Interferometric Synthetic Aperture Radar (DInSAR) data to develop an integrated, multi-scale model of initial land subsidence velocities across the GBD. The high-resolution topographic and subsidence data will be incorporated into hydrodynamic models to assess the impacts of current land motion on sediment transport patterns and coastal flooding risks. Here we generate detailed pre-subsidence inundation maps, drawing comparisons to vulnerable coastal cities like Lagos, Nigeria to illustrate the potential future flood impacts if the observed subsidence trends continue unabated. Future results will inform critical decisions regarding coastal adaptation strategies, flood risk management, and sustainable development, addressing the complex challenges facing the Ganges-Brahmaputra Delta