GEOMETRY PREDICTION FOR WAVE-GENERATED BEDFORMS

Published data on wave-generated bedform geometry from field and laboratory measurements are re-evaluated in terms of relative fluid orbit diameter at the bed, and a wave period parameter, X = rhoD/gamma(s)T2. Laboratory bedform data shows a strong dependence on these parameters. However, for very small values of the period parameter (typically field data), there is evidence that bedform length depends only on sediment grain size. The disappearance of sediment bedforms at high fluid velocities, apparently occurs through a decrease in bedform height. Improved methods for the prediction of bedform geometry under waves are provided in graphical form and computer code.