Depth-averaged modelling of vegetated meandering compound channel

Abstract

Advances of computing capabilities have increased the interest of using computational fluid dynamics to simulate more complex flow structures in open channel. A two-dimensional model, Telemac-2D was used to simulate flows with the presence of vegetation on the floodplain along the main channel inside a meandering compound channel. The simulation was done for two different relative depth for both non- and vegetated floodplain cases. The measured and simulated depth-averaged velocities were compared at the bend apex cross-section of the meandering compound channel for validation. Vegetation reduced the magnitude of the overbank flows and directed most of the overbank into the direction of the main channel. The effects of the vegetation on the overbank flows are more significant at low relative depth. The model shows good simulating capabilities of the depth-averaged velocities for the vegetated meandering compound channel and the numerical results also capable to generally capture the complex interaction between the overbank and inbank flows due to the presence of vegetation.