Abstract
The effect of the vegetation patch on the downstream flow and turbulence is investigated, including the effect of a length of a vegetation-patch on the development of mean and turbulence characteristics. Turbulence measurements were intensively conducted in partly vegetated-open-channel flows using Particle Image Velocimetry (PIV). The vegetation patch consists of emergent, rectangular array of cylinders in shallow flow. The mechanisms which control the development of coherent structure around the vegetation patch are also discussed. The results indicated that an increase in the vegetation patch length causes acceleration of the development of flow velocity and turbulence characteristics and increases the length of wake region downstream of the patch where its effect is significant.
