Talk:Wave run-up

Table of probabilities

@D McParland: In the section on continuing development, there's a table showing values of a, b, c, d for some probabilities. The table has no source. Maybe it reflects the formulas above? I don't see where the values of a, b, c, d come from.

The lowest probability in the table is 1 in 1,000. For waves with 10-second periods, there are 3 million per year, so I'd like to extend the table to a much smaller probability, to identify the highest runups over the long course of of a building's life, to know the freeboard needed. Of course this would also need a distribution of wave heights. Numbersinstitute (talk) 22:52, 1 July 2024 (UTC)

Hi, thanks for your comments. I had been meaning some time ago to go back and update the article somewhat with more detail and citations, but haven't got round to it yet. The coefficients originate from empirical studies and formulae developed by van der Meer (1988). These coefficients are specifically used in the run-up formula for rubble mound breakwaters, which takes into account factors such as permeability and wave characteristics. They apply only to rock armoured slopes, so would not be relevant in e.g. concrete armour units or a smoother, asphalt type revetment or breakwater. They reflect the fact that, in irregular random seas, the run-up value changes considerably from wave to wave. Just now I added in another reference which gives a more detailed explanation (Burcharth). To extend the table to a smaller probability, a statistical model is required as you say, combined with the run-up formula. In the next few days I'll try and revisit the article to make this clearer. D McParland (talk) 21:52, 2 July 2024 (UTC)