A Laboratory experiment of wave overtopping over dike on steep fringing reef

This paper presents a laboratory study to investigate the wave overtopping over dike on the fringing reef with a large steep fore-reef slope. The experimented models were set up in wave flume, considering three different slopes of dike combined with various wave and still water levels and different roughness cases. The research results indicate that wave overtopping over a dike on the fringing reef depends not only on the relative crest freeboard but also on a synthetic parameter typical for the wave hydrodynamic properties of the fringing reef characteristics and the slope of the dike. An empirical equation of wave overtopping discharge for dike on the fringing reef was derived based on an equation in EurOtop2018 by adding new synthetic parameter, and the comparison of the data from the new empirical formulas with the measured data showed good agreement. The proposed equation of this paper has been applied to estimate wave overtopping discharge over dike on the fringing reef having a large steep fore-reef slope.