Wave overtopping due to harbour resonance

Summarization: Harbour resonance and its contribution to wave overtopping are examined for a small irregular-shaped harbour in the eastern Mediterranean. Offshore wave measurements are used to determine the incident wave conditions during storm events. Resonant periods of the harbour basin are identified through in situ measurements at four different deployment locations during multiple storm events. Numerical simulations using a Boussinesq-type model and an idealised offshore spectrum yielded similar resonant frequencies to the field measurements and allowed us to visualise the corresponding resonant modes. Wave overtopping along the vertical docks of the harbour is inferred by combining numerical time series of free surface elevation with EurOtop formulae. Two approaches to estimate wave overtopping rates are examined and compared: a novel approach considering wave energy in the sea-swell frequency range and varying the freeboard through time series in the infragravity frequency range, and the conventional method that considers spectral parameters along the entire frequency range. The novel approach provides an estimate for the contribution of harbour resonance to wave overtopping considering that infragravity wave energy inside the basin is mainly resonance-driven.Presented on: Coastal Engineerin