A 1-D model for predicting surf zone waves around the Irish Coast

Our coasts face huge challenges due to future sea level rise. A main reason for this are the changes in waves which are expected to become more powerful. As these changes will affect our coasts, the prediction of wave changes play an important role in coastal adaptation and in industries like offshore wind energy. Ireland's extended coastline and its vulnerability to extreme wave events make it crucial to understand wave climate and its changes around the Irish coast.

The DeWaPic project intends to create a model framework for predicting waves around Ireland on time scales of seasons to decades. For this a global wave model, WAM, will be forced by climate model data and then coupled to a regional wave model, SWAN. In a next step the output of this model chain will be used to force a SURF zone model, with the target to generate information on coastal wave heights and wave overtopping.

This contribution will present the development of a 1-D SURF zone model, covering the final stretch towards the coast. The model solves one dimensional Boussinesq equation using a two step Lax Wendroff TVD scheme. The depth integrated approach in the model reduces the computational complexity that occurs when the grid size becomes smaller. Surface elevation and depth averaged velocity is modelled using the continuity and momentum conservation equations. We show first experiments with this model and determine in sensitivity tests its applicability.