Author(s): Stephen C. Medeiro; Naeko Takahashi; Qing Wang; Scott C. Hagen
Linked Author(s): Scott C. Hagen
Keywords: Storm surge; Hurricane Katrina; Finite element modeling; Li DAR; Pascagoula River; Landcover; Shallow water equations
Abstract: This study presents a storm surge simulation hindcast of Hurricane Katrina's (2005) effects on the Pascagoula River and associated tributaries located in southern Mississippi along the Gulf of Mexico. The domain is described by an unstructured finite element mesh of triangles that provide a large range in side length from approximately nine meters within the river banks to approximately414 meters on the continental shelf. The work is motivated by the absence of an existing model containing the resolution necessary to accurately describe storm tide propagation up the Pascagoula River and out of its banks. The model serves as a tool to understand the complex physics of this riverine system. Meteorological tides are computed using ADCIRC-2DDI, a two-dimensional depth integrated hydrodynamic circulation code applied over an inlet based unstructured finite element mesh incorporating the Pascagoula River and its tributaries. Surface characteristic data include recently acquired LiDAR data used to build the overland DEM and the National Land Cover Dataset interpreted to characterize the surface friction parameters. The fine resolution Li DAR and landcover data provide a detailed foundation for structuring the model's finite element mesh. In addition, the atmospheric wind models that are incorporated into the ADCIRC surge model produce wind speeds that assume open-ocean marine conditions; therefore, the wind speeds used in this study are adjusted via wind-reduction and surface canopy factors for overland and nearshore areas. Model results are compared to historical gage data, high water marks and the simulation results produced by a previous model without the detailed surface characteristics incorporated herein.
Year: 2009