Wave-Driven Sea Level Rise Inundation: American Samoa: Tutuila

CAUTION: THIS DATA PRODUCT IS A BETA VERSION IN ACTIVE DEVELOPMENT AND SUBJECT TO CHANGE. This dataset presents high-resolution simulations of wave-driven coastal flooding under sea level rise (SLR) along the coasts of Tutuila and Aunuu islands in American Samoa. Propagation, transformation, and run-up of the wave field were computed using a Boussinesq-type phase-resolving model (BARRACUDA: Boussinesq Approach for Rapid Runup Assessment with CUDA; Mihami and Roeber, 2026). The resulting wave-driven flood depth per grid point was then calculated as the 2% exceedance statistics. Three wave scenarios are included: (a) no waves (static), (b) annual high wave flooding (the maximum wave event expected in a typical year, with a 50% chance of being exceeded in any given 12-month period), and (c) 30-year high wave flooding (a severe wave event with a 3.3% chance of being equalled or exceeded in any given 12-month period). Each case is evaluated across SLR increments from 0 to 10 ft (3 m) in 1-ft steps. Wave simulations were conducted over a digital elevation model (DEM) that was derived from a 2022 1-m topobathymetric Lidar survey from NOAA blended with 2013 10-m Multibeam bathymetry for offshore regions and gap filling, resampled to a 5-m by 5-m grid resolution for the final computations. As a last step, the flood depth results are projected back onto the blended 2-m by 2-m DEM. Flood depths are referenced to Mean Higher High Water (MHHW) in 2005, derived from tide gauge observations at Pago Pago Harbor, which also serves as the background water level in the simulations.