Hydraulic roughness of coral reef platforms

This paper describes the derivation of the hydraulic roughness of a large, fixed bed, coral reef platform from field measurements. These measurements were made in near ideal conditions, where oscillatory waves propagated in water of constant depth, such that the only active wave transformation process present was that of wave bed friction damping. The derived roughness value enables relative roughness and friction factor values to be determined on this, or any other similar reef, for any combination of wave and water depth conditions ( T,H,h). The paper discusses the influence a low magnitude current may have had on the results, and finds it to be negligible. Some comparisons with movable beds are also made.