Abstract
Turbulence measurements of open-channel flows with vegetated zone at a half channel width were conducted by making use of a two-component laser Doppler anemometer (LDA). It was found that the intensity of secondary currents and the turbulence energy increase with increase of the Froude numbers. The turbulence is advected spanwisely near the free surface by the secondary currents, which are generated by surface vortices. The horizontal vortices near the free surface are generated by shear instability which increases with an increase of the. Froude numbers. The wall shear stress is calculated by the equation of motion with the aid of an empirical drag coefficient in vegetated zone. The calculated wall shear stress agrees well with the experimental values.
