Variable-resolution wave modelling for coastal applications

The Australian coastline and its sandy beaches are at risk of coastal erosion and inundation, when exposed to large waves, often in conjunction with elevated ocean water levels. Accurate predictions of how wave conditions transform from deep water to nearshore are essential for the development of robust coastal impact forecasting systems. The Bureau of Meteorology's operational wave forecast system (AUSWAVE) is relatively coarse in spatial resolution (1/10° around Australia) and is therefore not able to accurately represent the transformation of deep-water waves to the nearshore. To close this gap, a new high-resolution wave hindcast and forecast system has been developed to provide detailed wave information at the coast. The pilot system is an implementation of WAVEWATCH III® with variable resolution of up to 250 m in the coastal zone. The coastal wave models are nested within a new global configuration of AUSWAVE with a focus on the metropolitan coastline in Western Australia. Care has been taken to source the most accurate and up-to-date bathymetry data available. The model is forced with surface winds from the Bureau of Meteorology's operational Numerical Weather Prediction (NWP) System.