Abstract:

XBeach, a coupled hydrodynamic/morphodynamic numerical model, simulates erosion and deposition caused by Hurricane Ike on a 2.6 km stretch of West Beach, Galveston Island, Texas. Hurricane Ike, which made landfall in September 2008, is used as an illustrative future strong hurricane. Three dune morphologies consistent with Galveston, Texas Code of Ordinances and the Coastal Engineering Manual were used as input to examine the protection afforded the island from washover and erosion. A beach nourishment profile was also incorporated into two of the dune profiles to assess its role in dissipating storm surge and wave energy. This dataset contains the set-up scripts, wave and tide/surge data, LiDAR-based digital elevation models (DEMs) for 2006 and 2008, experimental dune or dune and beach nourishment profiles, and the model output (bed level, sea surface height, wave height, water velocity, and net erosion).

Suggested Citation:

Claire Rydman Pollard. 2021. XBeach model setup and results for beach and dune enhancement scenarios on Galveston Island, Texas. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7MP51R2

Purpose:

The investigation of the protection afforded by the dune system on Galveston Island, Texas, against coastal erosion and washover during Hurricane Ike. The efficacy of beach nourishment in dissipating storm surge and wave energy is also evaluated.

Data Parameters and Units:

The dataset contains two folders, 'XBeach Model Runs' and 'XBeach Model Setup'. The 'XBeach Model Runs' folder contains seven folders which include the input and output for the seven model runs. The input folders contain a 'README.txt' file which describes the contents of the folder. The output folder contains a netCDF file with the variables: globalx (local x coordinate, [m]), globaly local y coordinate, [m]), globaltime [s], zb (altitude/bed level, [m]), zs (sea surface height above sea level, [m]), H (wave height based on instantaneous wave energy, [m]), ue (Eulerian velocity in cell center, x-component, [m/s]), ve (Eulerian velocity in cell center, y-component, [m/s]), sedero (cumulative sedimentation/erosion, [m]). XBeach is available from deltares.nl.

Methods:

Producer = "XBeach littoral zone wave model (http://www.xbeach.org)" ; Build-Revision = "5117" ; Build-Date = "Fri May 12 16:11:53 CDT 2017" ; URL = "URL: https://svn.oss.deltares.nl/repos/xbeach/trunk/src/xbeachlibrary"; The 'XBeach Model Runs' folder contains folders for the input and output of the seven model runs, six hypothetical nourishment scenarios and the non-enhanced scenario. The input folders contain a 'README.txt' file which describes the nourishment design as well as a description of each file. XBeach model input parameter file description (params.txt): depfile = Name of input bathymetry file (bed.dep), nx = number of grid cells in x-direction, ny = number of grid cells in y-direction, vardx = switch for variable grid spacing, xfile = Name of file containing x-coordinates (x.grd), yfile = Name of file containing y-coordinates (y.grd), thetamin = Lower wave directional limit (Nautical degrees), thetamax = Higher wave directional limit (Nautical degrees), dtheta = Directional resolution (degrees), tstop = Stop time of simulation (seconds), instat = Wave boundary condition type, bcfile = Name of spectrum file, zs0file = Name of tide boundary condition series, bedfriction = Bed friction formulation, bedfricfile = Bed friction file, D50 = D50 grain size per grain type (meters), D90 = D90 grain size per grain size type (meters), morfac = Morphological acceleration factor, struct = Switch for enabling hard structures, ne_layer = Name of file containing depth of hard structure (Nebed.dep), mpiboundary = Fix mpi boundaries along y-lines, x-lines, use manual defined domains or find shortest boundary automatically. The dataset also includes a folder, 'XBeach Model Setup,' which contains the bathymetry and topography files used to set up the XBeach model grids. Also included is a 'README.txt' file which describes each file in the folder and MATLAB scripts that can be used to set up the XBeach model grid for each of the six hypothetical nourishment scenarios along with the non-enhanced/control scenario. The folder also contains the raw wave data acquired from Dr. Andrew Kennedy, University of Notre Dame (result_W.mat). These data, corresponding to yearday 255-258, were used to create the spectral wave boundary condition file, located in the 'XBeach Model Runs' input folders (jonswap.txt). Water level data were extracted from the United States Geological Survey (USGS) temporary surge sensor (SSS-TX_GAL-011) from 00:00 2008-09-11 to 00:00 2008-09-15. The data parameters and units are detailed in the 'README.txt' file located in the 'XBeach Model Setup' folder.

Individual Files: