HR: 10:35h
AN: H52A-02    [Abstracts]
TI: Numerical Simulation of Meandering Evolution
AU: * Duan, J G
EM: gduan@dri.edu
AF: Division of Hydrologic Sciences, 755 E. Flamingo Road, Las Vegas, NV 89119 United States
AB: Abstract: Evolution of meandering channels, a complex morpho-dynamic process, has been the focus of research challenging geomorphologists and river engineers for decades. The evolution of channel meandering is the result of the complex interactions between flow, sediment transport, and bank erosion. A numerical model including a depth-averaged two-dimensional hydrodynamic flow model, a sediment transport model, and a bank erosion model was developed to simulate the evolution of meandering channel from a low to high sinuosity. The sediment transport model calculates both bed load and suspended load assuming equilibrium sediment transport. Bank erosion simulation consists of two interactive processes: basal erosion and bank failure. The mass conservation equation where basal erosion and bank failure are considered source terms, was solved to obtain the rate of bank erosion. Then, this model was applied to simulate the evolution of free meandering channels in laboratory experimental settings. The model successfully replicated the evolution processes of meandering channel from downstream translation, lateral extension, and then follows by upstream and downstream rotation when sinuosity approaches 3.7. Plots of meandering planforms illustrated the evolution of meandering planform is a resultant of 1) redistribution of primary flow momentum due to curved channel geometry, 2) secondary flow generated by channel curvature and growing point bars, and 3) the material input from bank failure.
DE: 1847 Modeling
DE: 1849 Numerical approximations and analysis
DE: 1856 River channels (0483, 0744)
DE: 1861 Sedimentation (4863)
DE: 1862 Sediment transport (4558)
SC: Hydrology [H]
MN: Fall Meeting 2005