Strategies for Cutting Management of Riparian Vegetation

This study presents the numerical predictions on the detailed hydrodynamic and habitat quality characteristics of riparian vegetation by using a depth-averaged two-dimensional flow model. The model solves the depth-averaged Reynolds Averaged Navier-Stokes Equation. The vegetative effect is considered by a drag force exerted by the flow on the vegetation, resulting in extra source terms included in the momentum equations. Simulated results of flows in a rectangular and a compound channel with vegetation along one side are coincided with the previous experimental data. Furthermore, the model is used to simulate the cutting management of riparian vegetation. Five different scenarios are proposed in this study, including original, as well as cutting along main-channel side, cutting along bank side, alternative cutting and reducing vegetative density. The influence of the proposed scenarios on hydrodynamic behaviors is investigated in a rectangular channel. Simulated results suggest that cutting along the main-channel side is the most effectively scenario among others in reducing the water depths and flow velocities of the original one.