[S04B-02] Experimental Study on Formation Process of Three-Dimensional Antidune
Keywords:antidune, flow velocimetry
When three-dimensional antidunes are formed, the local velocity varies spatiotemporally from the average velocity. Therefore, it is pointed out that this may cause block instability. However, the method generally used at present, presents the design method of the block under the assumption of a flat fixed riverbed, and does not consider the effect of the antidunes. In order to consider the effects of the antidunes, it is necessary to understand the flow velocity distribution on the antidunes and the formation mechanism of the antidunes. However, the transition process, especially when the riverbed is formed from a flat riverbed, is still unclear. In this study, we measured the riverbed shape in the process of formation of three-dimensional antidunes from a flat riverbed in order to obtain basic data.