UNIFIED DIAGRAM ON SAND WAVES USING DEPTH–WAVELENGTH RATIO

Abstract

The classification of sand waves and their indices have been studied separately for sand bars, dunes and ripples. The flow over the sand waves was empirically defined as shallow water flow on sandbars and non-shallow water flow on dunes and ripples. In addition, the results of experiments and measurements of surface waves on sand waves in rivers have already been published in previous studies. We have discussed the relationship between these classifications and indices, the aspect of flow pattern on sand waves, and the water surface waves caused by them from the fluid dynamic point of view. The present study is based on the small amplitude wave theory, and uses the depth-wavelength ratio to determine the aspect of flow over sand waves and we developed an unified index that allows us to examine whether or not a river is represented, and compared it with the results of real and experimental flumes. As a result, we were able to classify the sand waves and flow pattern in a unified manner using the depth-wavelength ratio.