New Understanding on the Distribution of Individual Wave Overtopping Volumes over a Levee under Negative Freeboard

Distribution of individual wave overtopping volumes on mound breakwaters

“…Pan et al [13] examined the influence of the proportion of the largest overtopping events selected before fitting the Weibull parameters over a levee under negative crest freeboard. These authors considered selecting 100% (all overtopping events), the largest 50% and the largest 10%.…”

“…These authors considered selecting 100% (all overtopping events), the largest 50% and the largest 10%. Pan et al [13] recommended selecting all individual wave overtopping volumes to fit the Weibull parameters in order to achieve a better performance in the estimation of individual wave overtopping volumes. Pan et al…”

“…(2) and (3). Pan et al [13] then used the methodology of Hughes and Nadal [18] to identify individual wave overtopping waves for levees with negative crest freeboards under overflow and wave overtopping. The methodology used a script to analyze a wave sensor on the breakwater crest to identify waves as the number of time steps from one wave trough to the following trough.…”

“…Depending on the author, this Weibull free parameter is fitted as a constant value (see Van der Meer and Janssen [7]) or using different explanatory variables such as the relative crown wall crest freeboard and the slope angle (see Victor et al [10]) or the dimensionless wave overtopping discharges (see Zanuttigh et al [11]). However, Pan et al [13] and Gallach [14] pointed out that the two parameters of the Weibull distribution may not be related by the mean individual wave overtopping volume ( � ) and hence both parameters of the Weibull distribution should be fitted through the measured individual wave overtopping volumes.…”

“…Pan et al [13] highlighted that the criterion to select the data used to fit the Weibull parameters is not always the same in the literature and there is no justification in the chosen criteria. For instance, Victor et al [10] and Zanuttigh et al [11] analyzed smooth impermeable low-crested structures and, conventional and low-crested mound breakwaters, respectively, using the individual overtopping volumes higher than the mean value to better represent the largest volumes; Nørgaard et al [12] analyzed conventional mound breakwaters in breaking conditions using the 30% highest individual wave overtopping volumes to maintain a sufficient accuracy in the determination of individual overtopping volumes in the model tests with lowest amount of overtopping.…”