Intro

XBeach-Veg is a module of the XBeach model software that can take into account the effect of wave and flow damping due to vegetation. This wiki-page gives an overview on the model itself, how to use it, and typical applications. If you have any questions, please contact Arnold.vanRooijen@deltares.nl.

XBeach

XBeach is a numerical storm impact model software that allows for simulations of flow, waves, sediment transport and morphological changes (Roelvink et al., 2009). It is mostly applied for relatively short (hours to days) and medium-scale (few km's) applications, although nowadays paralel computing allows for longer and larger simulations easily. The model is in general very similar to Delft3D, but has a few differences. In contrary to Delft3D, XBeach computes the propagation of short (wind-generated) waves by itself (so no coupling with SWAN needed), and computes these waves on the scale of wave groups. Furthermore, XBeach computes the long, infragravity waves which are found to be important during storm conditions (Van Thiel de Vries, 2009). In short you could roughly say that XBeach is more accurate than Delft3D+SWAN, but it will also need a higher grid resolution, so simulations will take more time. Therefore Delft3D (i.c.w. SWAN) is generally used for longer simulations on a larger scale. For more information on XBeach, please refer to www.xbeach.org and Roelvink et al. (2009).

XBeach was originally developed for simulating the behavior of sandy coasts under extreme / energetic hydrodynamic conditions, specifically the processes of dune erosion (e.g. Van Thiel de Vries, 2009) and dune overwash (McCall et al., 2010). However, over the years several developments have lead to the very broad range of applications that XBeach is used for nowadays. XBeach is not only applied on sandy coasts anymore, but also on gravel coasts and coasts fronted by coral reef systems. And more recently, XBeach is being used to study erosion of (muddy) tidal flats. In addition to sandy, gravel, coral and muddy coasts, XBeach has been extended with a number of formulations to be able to simulate flow and waves on vegetated coasts (e.g. mangroves, sea grass, kelp etc.).  

Image Added

Example measured and computed wave height evolution for lab tests Kansy (1999),
with (measured: circles, model: solid line) and without (measured: squares, model: dashed line) vegetation.

Theory

General theory

This section describes the theory behind the current implementation in the XBeach model source code. However, at this moment code developments are ongoing, so this part is subject to change on a regular basis. 

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