AN EXPERIMENTAL STUDY ON THE TRANSFORMATION OF SAND WAVES (2)

In this study the authors found out some characteristics of transforming process of sandwaves based on a series of experiments with various initial bed forms.When the mean wave steepness is smaller than the equilibrium value for the givenhydraulic condition, new sand waves generate from the back surfaces of original waves, and the mean wave length rapidly reduces until the mean wave steepness approaches to theequilibrium value. On the contrary, when the mean wave steepness is larger than theequilibrium value, each wave is apt to be scraped out by the flow, and the mean waveheight rapidly reduces until the equilibrium value, both the wave length and the waveheight approach to the respective equilibrium values asymptotically with time.A model for tracing these phenomena is offered in this paper.