Wave overtopping III

Recurved walls are used to reduce wave overtopping over breakwaters. However, the mechanisms determining their effectiveness in terms of reducing the overtopping rate are complex and not yet fully described. Most of the available equations for overtopping rate estimations correlate only to the relative freeboard Rc/Hm0, neglecting other influencing parameters. However, in our study and also previous studies it was observed that the effect of other influencing parameters like wave period and water depth at the toe of the breakwater becomes more significant when a recurve is added to the top of the breakwater or revetment. In this research, the effect of these parameters on wave overtopping rates is investigated for vertical walls with recurve on top. For this study, data from the so-called SABAII project (a commercial port study for the Caribbean Island SABA) conducted at Ghent University and a part of the EurOtop database are used.

Facing increasing climate change threats like rising sea levels and intense storms, adapting coastal defense structures has become crucial. This study investigates the use of Stilling Wave Basins (SWB) on slope structures to mitigate wave overtopping, a cost-effective solution that avoids raising crest levels. SWBs are designed to capture and dissipate wave energy, reducing overtopping risks. The research reviews various formulae on SWBs and evaluates their efficacy, utilizing datasets from prior studies. This data-driven approach proposes a reduction factor accounting for the SWB impact. The study underscores the significance of SWBs in enhancing coastal resilience but emphasizes the need for meticulous design considerations.

In the era of climate change, the adaptation of existing coastal structures as a response to potential increasing loads, has become a trending topic in coastal engineering.
In this context, this research is focussed on the evaluation of wave overtopping for conventional rubble mound breakwaters, modified by the introduction of a submerged berm. Recent studies illustrated how the introduction of emerged berms on the seaward slope reduces the wave overtopping. The goal then becomes to turn the spotlight on the submerged berms, whose effectiveness has yet to be attested. Therefore, the reliability of two different numerical models in detecting overtopping phenomenon have been assessed.
IHFOAM and SWASH have been used. The numerical models have been validated on the basis of experimental tests.
After highlighting their strengths and weaknesses, the numerical tools have been employed to evaluate the role of the submerged berm configuration on the overtopping discharge.

In many tidal flat regions like the Yangtze River Delta, vegetation naturally grows alongside dikes and offers wave dissipation benefits. Studies by Suzuki et al. (2019) have shown that vegetated foreshores effectively dissipate waves. They also reduce flow velocities, leading to sediment accumulation, as observed in research by Chen et al. (2012) and Hu et al. (2018). Despite this potential, limited research has explored the influence of vegetation on wave overtopping across coastal dikes. This research employs laboratory experiments within the wave flume facility at Dalian University of Technology in China to investigate how vegetation impacts wave overtopping. The study examines factors like vegetation density, width, and relative height on wave overtopping for both vertical walls and sloping dikes, and establishes relationships between vegetation configurations, wave conditions, and overtopping discharges.