The Impact of Double-layered Rigid Vegetation on Flow Structure

Flow structure in vegetated channels is highly three-dimensional. This study focuses on the characteristics of flow through the mixing layered vegetation partially covered in an open channel. A series of experiments were conducted to investigate the velocity distributions in the vegetated zone under different flow conditions. Reynolds shear stress was calculated based on 3D measurements using ADV (Acoustic Doppler velocimeter). Observed results show that the flow has distinct features in three layers: the lower, mediate, and upper layer. A prominent shear stress layer is found at the upper edge of tall vegetation, indicating strong momentum exchange in this transition region.