Cutting management of riparian vegetation by using hydrodynamic model simulations

This study numerically investigates effects of cutting riparian vegetation on flow characteristics by using a two-dimensional numerical model. The numerical model is based on depth-averaging the time- and volume-averaged Navier-Stokes equation with turbulent effects determined by the standard k-ε turbulence model. Drag forces exerted by the flow on vegetation are considered by adding source terms into momentum equations. In a rectangular channel and compound channel with vegetation along one side, numerical predictions show are in good agreement with those of previous studies. Five cutting scenarios, including the original, cutting along the main channel side, cutting along the bank side, alternative cutting, and reducing vegetative density, are analyzed in this study. The influences of the cutting scenarios on hydrodynamic behaviors are evaluated via numerical simulations. Simulation results suggest that cutting along the main channel side is the most effective scenario for reducing water depth and flow velocities.