Deltares: Modelling Storm-Impacts on Gravel Coasts

Gravel beaches occur on many wave-dominated coasts across the world and are widely considered an effective and sustainable form of coastal defense.

Despite their societal importance, relatively little research has been directed towards understanding the mechanisms leading to their failure during storms.

As a result, coastal managers have very limited guidance when estimating the potential for flooding on gravel coasts.

Robert McCall addressed the current gap in predictive storm-impact models for gravel coasts in his doctoral research at Plymouth University UK, in collaboration with Deltares and project partners the Channel Coastal Observatory, the Environment Agency, HR Wallingford and UNESCO-IHE, as a part of the NUPSIG project.

His research resulted in the development of a new, process-based, open-source numerical model called XBeach-G.

The XBeach-G model, which is based on the existing open-source model XBeach, simulates the impact of storms on gravel beaches and barriers by solving the hydrodynamics of individual waves in the nearshore and swash zone, wave run-up and overtopping flows, groundwater processes in the beach and barrier, sediment transport and morphological change of the beach during the storm.

To ensure easy uptake of the XBeach-G model by coastal managers and engineering firms, Deltares and Plymouth University have developed a free and easy-to-use graphical user interface (GUI) for the XBeach-G model.