Abstract
In this study, the mechanism of transverse mixing in open-channel flow with longitudinal zone of vegetation along side wall is investigated. Flume experiments with idealized vegetation zone are conducted. As a result, the followings are postulated: transverse mixing is caused by rather organized and low-frequency fluctuation of transverse velocity, and it is maintained by association of water-surface fluctuation. By hydraulic analysis where vegetated and non-vegetated zones are treated separately as two neighboring one-dimensional flows but considering the alternate transverse flow at the interface between them, the phase relations among respective velocity components and water-surface fluctuation are explained.
