Storm-Impact Scenario XBeach Model Results – Scenario 7 Digital Elevation Model (DEM) Grid

The numerical model XBeach (version 4937) was used to investigate how different storm scenarios impact the sediment berm constructed offshore of the Chandeleur Islands and adjacent areas. The XBeach model solves coupled 2-dimensional, horizontal wave propagation equations to predict flow, sediment transport, and bottom changes for varying spectral wave and flow boundary conditions (Roelvink and others, 2009 ). The XBeach model setup requires the input of a merged topographic and bathymetric DEM, and inputs of wave spectra (based on significant wave height, peak wave period, and wave direction) and water level (tide and surge) time series at the seaward model boundary that span the duration of each storm bin. The Xbeach model input and output of topography and bathymetry resulting from simulation of storm-impact scenarios at the Chandeleur Islands, LA, as described in USGS Open-File Report 2017–1009 are provided via a USGS data release (storm scenario bins where no events were observed are excluded). For further information regarding model input generation and visualization of model output topography and bathymetry, refer to Mickey and others (2017).