FLOW MECHANISM OF OPEN CHANNEL FLOW WITH DISCONTINUOUS VEGETATION IN THE FLOW DIRECTION FOR OVERFLOW CONDITIONS

Abstract

 In the Gosegawa and Shingosegawa rivers in Aichi prefecture, environmental groynes are arranged in parallel and in a staggered manner in the river channel to create various flow fields. In this study, we experimentally analyzed the three-dimensional turbulent structure and momentum transport characteristics of an open channel flow with discontinuous vegetation communities in various arrangements in the flow direction, targeting overflow conditions. As a result, it was found that the secondary flow characteristics changed in the flow direction due to the influence of having a non-vegetation area in the flow direction, and the flow was greatly advected at the overflow point. In addition, in staggered and parallel arrangements, it was clarified that momentum transport by advection is superior to turbulence, suggesting that the momentum transport characteristics around the vegetation zone affect the magnitude relationship of the flow resistance characteristics.