THE BLOCKING EFFECT OF PARALLEL FRINGING VEGETATION ARRAYS ON FLOW STRUCTURE DYNAMICS

To investigate the blocking effect of parallel fringing vegetation arrays on the flow dynamics and turbulence characteristics, the experiment examines a vegetated-channel-vegetated system. The vegetation array adjusts the flow by producing a lateral flow deflection, diverting a part of flow from the vegetated region to the free stream region. The flow diversion creates a velocity shear across the edge, which varies with array density and width. A denser array intensifies the lateral flow, leading to a higher velocity shear across the interface. This enhanced velocity shear produces a greater Reynolds shear stress at the array edge. Moreover, the amplified blocking effect highly enhances the interfacial shear stress, despite the interfacial velocity shear is diminished due to the reduced flow diversion associated with a wider array.