|Shields Jr, Fletcher|
Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2005
Publication Date: 3/16/2005
Citation: Wu, W.M., Shields Jr, F.D., Bennett, S.J., Wang, S.Y. 2005. A depth-averaged two-dimensional model for flow, sediment transport, and bed topography in curved channels in riparian vegetation. Water Resources Research. 41, W03015, doi:10.1029/2004WR003730.
Interpretive Summary: Living and dead vegetation exerts an important influence on patterns of erosion and sediment deposition in stream channels and adjacent riparian zones, thus vegetation and large wood are often used for erosion control and habitat rehabilitation along streams. However, the interaction of vegetation with the movements of water and sediment is quite complex and its effects are hard to predict. A computer model was developed to simulate the changes that occur in a stream channel with rigid vegetation growing on the banks or with simple structures made from tree trunks placed on the bank and bed. Comparison of model results with laboratory and field data indicated that it provides accurate simulation of the behavior of real systems when properly calibrated. This model will be useful for future studies of vegetation and large wood in stream corridors.
Technical Abstract: A depth-averaged 2-D numerical model has been developed to simulate flow, sediment transport, and bed topography in river channels with emergent or submerged vegetation and large woody debris. The effect of secondary flows in bends is considered by adopting an algebraic model for the dispersion terms in the depth-averaged 2-D momentum and suspended-sediment transport equations and by adjusting the bed-load transport angle. The governing equations are discretized using the finite volume method on a non-staggered, curvilinear grid. Model output is compared with data from both fixed- and movable-bed flumes and field measurements of open channel flows with riparian vegetation. The simulated results show very good agreement with observed mean flow velocities, sediment transport rates and changes in bed topography.