M.V. Bilskie, S.C. Medeiros, S.C. Hagen, “Development of a High-Resolution Tide-, Wind-, and Wave-Driven Ocean Circulation Model for the Northern Gulf of Mexico.” 12th International Congress on Computational Mechanics, Raleigh, NC, July 22-25, 2013.
Abstract:The northern Gulf of Mexico is a complex hydrodynamic system including low-lying topography and networks of rivers, bays, marshlands, the Intracoastal Waterway system, along with a wide and flat continental shelf. The intricate geometry creates an interesting scenario for studying sea level rise and hurricane storm surge. To capture the hydrodynamic response to sea level rise and hurricane storm surge, a large-scale, high-resolution wind-wave, tide, and hurricane storm surge model was developed that incorporates a tightly coupled shallow water coastal circulation model and wind wave model (ADCIRC+SWAN). With any coastal inundation model, the overland topography and frictional parameterizations are crucial to the simulated hydrodynamics. Sub-scale terrain features were incorporated into an unstructured finite element mesh and elevations were assigned from interpolating lidar- and survey-derived digital terrain models using a cell averaging method to minimize vertical errors in elevation (Bilskie and Hagen, 2013).
In addition, surface roughness parameters (i.e. Manning’s n, surface canopy, and surface directional effective roughness length [Z0]) were generated from an enhanced parameterization scheme that uses lidar point cloud data to augment look-up tables based on land cover databases. The preliminary finite element mesh contains ~4 million nodes and provides full coverage from the Bay of St. Louis, MS to Apalachee Bay, FL. Mesh resolution in the Gulf is near 5 kilometers, 1 kilometer on the continental shelf, 100 meters along the shoreline, and down to 40 meters in marsh regions and small channels.
Validation consisted of two historical events, Hurricane Katrina and the Deepwater Horizon oil spill (DWH). Hurricane Katrina was simulated and results were compared to observed water levels and recorded high water marks. Simulated inundation area for the DWH was compared to satellite-based observations of the inundation area from processed SAR (synthetic aperture radar) imagery (Medeiros, et al., 2012).
Bilskie, M. V., and Hagen, S. C. (2013). “Topographic Accuracy Assessment of Bare Earth Lidar-Derived Unstructured Meshes.” Advances in Water Resources, 52, 165-177.
Medeiros, S. C., Hagen, S. C., Chaouch, N., Feyen, J. C., Temimi, M., Weishampel, J. F., Funakoshi, Y., and Khanbilvardi, R. (2012). “Assessing the Performance of a Northern Gulf of Mexico Tidal Model Using Satellite Imagery.” Coastal Engineering, In Review.