FIELD MEASUREMENT OF BED ROUGHNESS FOR WAVES ON AN OFF-SHORE REEF

Resumen

This paper takes advantage of fortuitous, near ideal conditions which existed for a subset of field data, to obtain the hydraulic roughness of the surface of a coral reef platform. This was accomplished by observing the transformation of natural, unbroken, oscillatory wave trains, propagating over the reef top in water of constant depth, where wave bed friction damping was the only active wave transformation process. The paper also demonstrates that while coral reefs may be perceived as being much rougher than sandy beds, they may in fact be no rougher in hydraulic terms, than many sandy beds experiencing the same wave and water depth conditions.