Improved guidance on roughness and crest width in overtopping of rubble mound structures along EurOtop

In this paper existing guidelines to predict wave overtopping on rubble mound breakwaters and coastal structures are modified improved with respect the influence of roughness crest width. Data from recently made model tests data combined demonstrate need for modifying these formulations in EurOtop. A new reduction factor γcw width is established an improvement method by Besley. The slope normally include also breaker parameter when it larger than a certain limit (EurOtop suggest ξm-1,0 > 5). present study shows that not ideal dimensionless describing period steep slopes, as such front has much less steepness. Thus angle steepness have been uncoupled describe armour overtopping. prediction compared EurOtop significant, specifically sets outside range calibration used proposed methods enlarge applicability