Simulating shoreline retreat in a 2D hydro-morphological model

Crynodeb

XBeach is a simple 2-D, hydrodynamic-morphologic coupled model using a finite difference explicit scheme. One of the practical improvement for XBeach is to simulate bank erosion. We started with considering a simple case where a vertical bank retreats in a predefined direction. The shoreline is described as straight segments of line parallel to y-axis. Along with the retreat process of the shoreline, cells adjacent to the shoreline change their width, which has to be accounted in the continuity and momentum equations. Tests of shoreline retreat with straight and curved shoreline show stability of the model. A shoreline with arbitrary orientation is then modelled as a polygon cutting through grid cells. We adjust the continuity equation and part of the advection terms in the momentum equation to make the model perform better in case of cut cells. Hydrodynamic tests with a straight, diagonal channel and bent channel show that the flow field calculated using the cut cell method is much better than the traditional "staircase" boundary. Finally, an application of modelling flow pattern among the groins in Haihau coast, Vietnam on real bathymetry data is carried out.

Dyddiad Dyfarnu	2007
Iaith wreiddiol	Saesneg
Sefydliad Dyfarnu	IHE Delft Institute for Water Education
Goruchwyliwr	Dano Roelvink (Goruchwylydd)