A new 1D-numerical model for flexible vegetated channels

This paper suggests a simple new numerical scheme for calculating the vertical velocity profile, turbulent shear stress distribution and canopy deflection for flow in vegetated channels. The scheme is derived from the simplified, steady Reynolds equation (momentum balance) and its vertical integration. This study includes an experiment that compares and calibrates the numerical model to flume data. Fourteen runs were performed in a laboratory flume, of which nine involved natural grass (cultivated barley) and five involved plastic plants (PVC). Turbulent diffusion coefficient, mixing length, and a resistance equation (drag coefficient Cd vs. Reynolds number) were the input parameters for the numerical model. Parameters with physical meaning were calibrated. This scheme offers a low computation time and good estimation of plant deflection and velocity and stress profiles.