Simon uses a world famous surf spot at Gold Coast as a case study to investigate the impact of large scale changes in near shore bathymetry - viz. a sediment-starved compared to a highly nourished setting - on surfing amenity.
Coupling the efficient Boussinesq type wave model MIKE 21 BW and the DHI’s fully non-linear Volume of Fluid model NS3, he calculates the full wave transformation from offshore to near shore including the complex wave overturning and breaking. The detailed resolution of the 3D wave breaking processes allows obtaining characteristic surf quality parameters such as breaking wave propagation, wave steepness, surf speed and longest possible ride. These are subsequently evaluated with respect to surfing skills (intermediate vs. expert). Thereby, the model gives a clear indication of the effects of changes in near shore bathymetry, e.g. by coastal protection measures or dredging for navigational purposes, on surfing amenity. "Coastal management in such areas as the Gold Coast is an extremely challenging endeavor due to the large number of stakeholders, such as surfers, swimmers, boaters, divers or beachfront property owners, all having different and often conflicting preferences to coastal management strategies", explains Mortensen. "Including the coupled modelling approach into a coastal impact assessment means adding an accurate and cost-effective tool for quantifying potential impacts to surfing with comparatively little additional effort". |