Calculating shear stress at channel-overbank interfaces in straight channels with vegetated floodplains

A series of eight experiments was performed in a physical model of a compound channel to quantify the apparent shear stress at the interface between a main channel and both a vegetated and unvegetated floodplain. Data were analyzed using a turbulence-based method for calculating the apparent shear stress as a function of the fluctuation in channel velocities. A predictive expression was developed to permit the estimation of the apparent shear stress at the boundary of a main channel and floodplain as a function of the bed shear stress, average velocity, and depth in both the main channel and floodplain and the blockage caused by floodplain vegetation.