Advancements in a Global Statistical Coastal Flood Modeling Framework

An accurate and efficient prediction of global coastal flooding is required to analyze the risk associated with future climate scenarios. In this work, we improve upon the existing statistical framework of Jupiter’s Climate Score Global (CSG) coastal flooding product (90 m resolution) that provides flood depths based on future total water levels (TWL) obtained at coastal boundary points. The TWL obtained at coastal boundary points drives the inland inundation to get flood depth information. We upgrade the TWL projections by incorporating the latest IPCC sea level rise datasets while adding the impact of waves and updating our historical datasets of tide and storm surge. We improve the inland inundation predictions by including the effects of storm surge dissipation. This is achieved through the calculation of hydraulic flow distance from coastal boundary points and by using empirical dissipation rates for different return periods. The flow distances are modified by land use coverage information to obtain more realistic flood paths. We further integrate the presence of levees in the US and parts of Europe to improve the fidelity of our coastal flooding product. The outcome of these improvements is demonstrated by comparing the flooding predictions with the output of deterministic high resolution numerical models available at two different geographical locations (Boston and Rotterdam). This advanced coastal flooding framework improves the skill level of Jupiter’s flood predictions at a significantly reduced cost of computation for modeling future risk scenarios.