The devastating effects of hurricanes in the U.S. on low-lying sandy coasts have pointed to an urgent need to be able to assess the vulnerability of sandy coastal areas and (re-)design coastal protection for future events. With launching funding by the U.S. Corps of Engineers, XBeach was developed to provide a tool with which morphological effects due to hurricanes can be simulated and measures can be evaluated.

Deltares, together with UNESCO-IHE and TU Delft have developed the open-source, freeware numerical model XBeach. The model is used for the computation of nearshore hydrodynamics and the morphodynamical response during storm-events, such as dune erosion, overwash and scour around buildings. Deltares uses this model in research projects, consultancy and advice, such as the assessment of dune safety in complex situation along the Dutch coast and in hindcasting hurricane impacts in the U.S., and provides training in the use of the model.

This process-based ( based on physical principles) model can simulate the 2D-horizontal nearshore hydrodynamics of waves on the time scale of wave-groups, including surfbeat (long waves, infragravity waves) and wave-induced currents in combination with non-cohesive sediment transports, avalanching of dune fronts and morphological change on the time scale of storm events.

While originally developed for the US situation, the model has been adapted and validated to be used as a dune safety assessment tool by the Dutch Public Works Department and Waterboards for the evaluation of complex two-dimensional situations such as curved coasts, hybrid coastal protection works combining hard and sandy elements.

In two European projects, FP7-Micore and FP7-RISCKIT it has been applied to coasts along every European regional sea under a variety of conditions. In addition the model has been extended so that it can be applied to (coral) reef-lined coasts (together with the U. Western Australia and the USGS) , gravel coasts (together with the U. Plymouth) and vegetated coasts (together with UNESCO-IHE) . It is even possible to compute ship-induced waves.

The model is supported by a software course, a manual, a user-interface and a validation document.  The XBeach model has a large and expanding community of users, and has been independently validated in more than 60 peer-reviewed articles.