COAST 3D: Coastal Study Of Three - Dimensional Sand Transport Processes and Morphodynamics

The purpose of the COAST3D project was:

• to improve understanding of the physics of coastal sand transport and morphodynamics
• to remedy the present lack of validation data of sand transport and morphology suitable for testing numerical models of coastal processes
• to test a representative sample of numerical models for predicting coastal sand transport and morphodynamics against this data
• to deliver validated modelling tools, and methodologies for their use, in a form suitable for coastal zone management
• to deliver a set of guidelines for practical coastal zone management (CZM)
  

This was achieved by making field measurements purpose-designed for numerical model evaluation, with adequate boundary conditions and a dense horizontal array of measurement points, in conditions typical of the European coastline. Previous coastal experiments in Europe and elsewhere had placed their main emphasis on hydrodynamics; an innovative feature of the present project was that the emphasis throughout was on sand transport and morphodynamics.

Another distinctive feature was that the focus is on non-uniform (3D) coasts, rather than on the relatively well understood (but possibly unrealistic) uniform 2D case. Experiments were performed at two contrasting sites: a quasi-uniform (2.5D) stretch of the Dutch coastline, in which the three-dimensionality was provided by rip-channels intersecting a breaker-bar system; and a fully 3D site on the UK coast, featuring a beach and spit adjacent to a tidal inlet and rocky headland. This phased approach allowed both the process information and the performance of the numerical models to be more easily interpreted.

Innovative techniques were used in the experiments. Numerical modellers worked interactively with the experimenters, at the planning, experiment, and evaluation phases. Participants from national regulatory authorities ensured that the project was focused on practical tools for coastal zone management.