The influence of berms, roughness and oblique waves on wave overtopping at dikes

Dikes protect inland from storm attack. Dike breaching can cause extensive damage and loss of lives. Wave overtopping is one of the failure mechanisms of dikes, which must be taken into account when designing a dike. In practice, berms and roughness elements at the waterside slope are widely applied to reduce the wave overtopping. Additionally, the direction of incident waves is often oblique relative to the coastal structures. However, these effects have not been fully understood. Better estimates of these influence factors will help improve the prediction of wave overtopping and lead to more suitable estimates of the risk of coastal flooding events.