High-Resolution Assessment of Coastal Flood Risk Under Future Climate Scenarios in Atlantic Canada

Coastal regions of Atlantic Canada face increasing tropical-cyclone flood risk under climate change. This study presents a building-level coastal flood-risk framework that translates regional synthetic-hurricane projections into localized risk estimates for Charlottetown, Prince Edward Island. The methodology combines coastal flood simulations with sea-level rise (SLR), AI-based exposure mapping using BRAILS, and HAZUS depth–damage functions selected according to building characteristics. Historical extreme-surge thresholds become more frequent under some future climate forcings, although changes are strongly GCM- and location-dependent. Locally, SLR acts as a dominant risk multiplier: under the EC-Earth3P-HR far-future scenario with SLR, the 100-year flood extent increases by approximately 59% relative to historical conditions. The proportion of buildings assigned to the highest descriptive structure-damage-ratio bin (>50%) also increases. Simplified North American depth–damage functions produce damage-ratio estimates 15–30 percentage points higher than HAZUS, highlighting vulnerability-model uncertainty.