The objectives of the Task 1 work are to: (1) develop and maintain updated topobathymetric digital elevation models (TBDEMs); (2) collate and characterize coastal sediment type and grade that can be used as inputs for morphodynamic models; (3) develop general coastal vegetation characteristics that can be used as inputs for models; (4) inventory and characterize structures and infrastructure types spatially such that they can be ingested by models. These results will better equip coastal models leading to improved hurricane impact projections. The products from this Task provide the other NOPP project teams with rich datasets for use as baseline conditions for producing remotely sensed DEMs (Task 2), collecting in situ measurements (Task 3), and modeling storm impacts (Task 4).
The study area for this effort includes the U.S. Gulf of Mexico coast and the U.S. Atlantic Seaboard. Along these coastal margins, the study area spans from the close out depth (depths of minimal sediment movement) to the NOAA National Hurricane Center Maximum of the Maximum (MOM) Envelope of High Water for a Category 4 storm for Virginia northward and Category 5 storm south of Virginia. The elevation-based nature of the study area provides models with boundary condition data needed to predict impacts from extreme storms, especially in coastal areas with low terrain slope such as the southeastern U.S.
Due to the large extent of the study area, the Team is using a three-tier approach. While these tiers differ slightly for each product type (TBDEMs, sediment, vegetation, and structures and infrastructure), the general approach is similar. Tier I products will provide coverage for the entire study area by the end of the first year of the project. Tier II products will include enhancements to the initial Tier I products over the project life cycle. Tier III products will focus on advancing research and development related to coastal TBDEM uncertainty, grain size mapping at high-resolution from satellite imagery, remotely sensed vegetation characteristics, and assessing post-storm structure and infrastructure damage. Collectively, these Tier III products and analyses provide opportunities to advance the science of coastal dynamics, storm impacts, and advancing coastal morphologic modeling. The Team will use one Tier III site per coast. The Gulf of Mexico site is the western Deltaic Plain of Louisiana and the Atlantic Seaboard site is the Outer Banks of North Carolina.
The outcome of Task 1 research and development will be manyfold. Complete coverage of updated high-resolution TBDEMs, an approach for estimating sediment grain size from space, high-resolution vegetation maps with corresponding vegetation structure parameters, and updated structure and infrastructure layers and enhanced storm damage summaries are among the highlights of the research.
by Martha Schönau, Luca Centurioni, Steve Jayne, and Elizabeth Sanabia
Hurricane Ian was the first 2022 hurricane to make landfall in the continental USA with strong Cat 5 winds and large amounts of rain. The team of Deltares USA, Deltares Netherlands, USGS and NRL successfully applied the COSMOS modelling system to forecast hurricane Ian’s flood and morphological impact.