河床波の変形過程に関する実験的研究

Abstract

Sand waves in an alluvial channel are not necessarily in an equilibrium state during flood.Therefore, their growing and diminishing processes may be considered to take an important role inthe mechanism of flow resistance, sediment transport and bed transformation. In this study, theauthors carried out some experiments on the transforming process of sand waves under unsteadyflow conditions, and found the following interesting results.For given hydraulic conditions, there is a preferable linear combination between the meanwave length Λ and mean wave height ⊿. When a bed form is not in the equilibrium state(Λe, ⊿e), Λ changes at first until the linear relation is fulfilled, thereafter both of Λ and ⊿ changestoward Λe and ⊿e along it.