Laboratory observations of bedforms under directional irregular waves

Abstract

Large-scale laboratory tests of the evolution of bedforms in sand beds, under directional irregular waves, carried out at the National Research Council Canada, are described. Preliminary observations indicate that the directionality of the waves is not an important factor; bedforms remained largely two-dimensional under all but transitional conditions. Incident wave height and period, probably combined as a wave orbital amplitude near the bed, seems to be the most important factor in determining bedform dimensions, followed by the D50 sand size on the bed. Sand gradation may be unimportant. Key words: seabed, sand, water waves, bedforms, morphology, roughness.