CoSMoS 3.2 Northern California projected water level: Humboldt County

After setting up tier 3 XBeach models for all storm and SLR conditions used in tier 2 sub-regional models and completing all simulations on high performance computing resources, all simulation data were downloaded and post-processed to extract maximum water levels at each grid point over the entire simulation, in addition to the associated duration of the water over the simulation. Significant wave height and velocity were similarly processed from tier 2 sub-regional models. For each output variable, maximum values for all contributing events in a storm scenario are composited to show the total maximum value for the scenario at each grid point from all simulations (for example, maximum output for all 100-year storm events are composited to a single 100-year scenario data layer). See O'Neill and others (2018, 2024) for information on CoSMoS framework, set up for simulations, and processing. Maximum output for water elevations were depth-differenced to the DEM to separate low-lying vulnerable areas from contiguous coastal flooding. Other output data (water elevation, flood depth, maximum current velocities, maximum wave heights) were clipped to final flood hazard extent. Flood potential projections (maximum and minimum flood uncertainty) were derived by adding/subtracting estimated model error, DEM uncertainty, and projected VLM for a given SLR to the respective water elevation surface. See O'Neill and others (2018) for a full discussion.

Final projected data are labeled by scenario indicating a given SLR (SLRs of 0 m, 0.25 m, 0.5 m, 0.75 m, 1.0 m, 1.5 m, 2.0 m, 2.5 m, 3.0 m, and 5.0 m) and storm condition (no-storm, 1-year storm, 20-year storm, and 100-year storm). For projected flood depths, duration, maximum current velocities, maximum wave heights, and water elevation, data are sub-divided into blocks. Blocks are labeled 'HUXX', where 'XX' is a sequential block number starting with '01' in the south and increasing to '12' heading northwards. Data are packaged in zip files by storm scenario.