Impulsive wave overtopping with toe scour at a vertical seawall

Reliable prediction of wave overtopping rates and scour depths are crucial for the design of sea defences, particularly in a changing climate. Here, we present a novel numerical modelling approach in investigating the impact of toe scour on wave overtopping over a vertical wall, using a RANS-VOF wave model and measured bed profiles collected by Sutherland et al. (2006). We calculated mean wave overtopping discharge and identified the underlying physical processes of wave overtopping through analysis of the model data for two considered configurations. The resulting findings of this study suggest that toe scour reduces wave overtopping by promoting wave breaking over the deposition from toe scour. However, when the toe scour dominates and deposition was insignificant, it caused an increase wave overtopping rates by allowing more large waves to reach the seawall.