Journal of Waterway, Port, Coastal, and Ocean Engineering

Grid point pooling is a commonly used method to account for hurricane track variability in extreme value analysis. This paper presents a simplified mathematical interpretation of grid point pooling. Through logical arguments and numerical experiments, some general guidelines are then developed for a selection of grid points to include in the statistical pool.

A comparative assessment of available formulae for the water setup inshore of submerged breakwaters is made on the basis of a wide and varied dataset derived from basin and flume laboratory experiments. Formulae derived from a simplified view which does not account for the horizontal flow circulation provide a large overestimate (up to one order of magnitude) of the smaller setup values. A much better overall approximation of the measured data is obtained through formulae that consider the setup as part of a complete flow description, be it partially or fully accounting for the horizontal flow motion.

Offshore wave setup generated by wave breaking during coastal storms can create significant flow through tidal inlets and increase bay flooding. However, these flow contributions are not always considered when determining coastal flooding risk for engineering studies. This paper describes the wave-driven flow process at tidal inlets and demonstrates its impact on bay flooding on Long Island, New York. Numerical simulations using a coupled hydrodynamic and wave model are presented to show contributions to bay water level by wave-driven flow with respect to those by wind surge. These simulations include two major historical coastal storms and a small nor’easter in 2003, during which the model was validated using field measurements of water level. Finally, an approach is introduced for estimating wave-induced flow contributions to bay flooding as a function of inlet and storm characteristics, including tidal prism and wave conditions. The findings of this study indicate that wave-induced flow contributions make up 15–35% of the total storm surge, where the wave-induced flow contribution increases with increased inlet efficiency.

This paper reports experimental results of the toe scour of seawall on a steep seabed with slope of 1:5 under the action of breaking waves. The equilibrium toe scour profiles were investigated and the depths of toe scours related to the wave parameters were analyzed. Experimental results indicated that the depth of toe scour increased as the steepness of the incoming wave increased, but decreased with an increase in the water depth at the toe. The breaker types in front of the seawall were investigated. The scour depth due to a plunging breaker is larger than that of a spilling breaker or a nonbreaking wave in front of the seawall. The down-rush flow velocity induced from the wave rundown on the seawall was also investigated in the experiment, and it was found that the scour depth increased as the flow velocity at the toe increased. Empirical formulas of the relative scour depth in terms of the relative toe water depth or surf similarity parameter were obtained based on the experimental results.