HR: 1340h
AN: H43A-0353    [Abstracts]
TI: Computational Model Of Width Adjustment In Meandering Channels
AU: * Chen, D
EM: dchen@dri.edu
AF: Desert Research Institute, 755 E. Flamingo RD, Las Vegas, NV 89119 United States
AU: Duan, J G
EM: gduan@dri.edu
AF: Desert Research Institute, 755 E. Flamingo RD, Las Vegas, NV 89119 United States
AB: Widening in sinuous channels occurs when the retreat of outer bank exceeds the advance of the opposite bank. This paper presented an analytical model to simulate width adjustment in meandering channels by calculating bank erosion at both banks. The solution to flow field in sine-generated channels indicated that bank erosion could occur at the bank where velocity is moderate. Concerning the phenomenon of bank retreat for non-cohesive materials, two consequent processes: basal erosion and bank failure, were recognized. The rate of basal erosion was calculated as a function of the gradient of longitudinal sediment transport rate and the strength of the secondary flow. The transverse bed slope was treated as a variable increasing with channel sinuosity until it reaches its maximum value. This study showed that the rate of bank line retreat for non-cohesive materials was determined by basal erosion rate, near-bank bed degradation rate, grain size, and the difference between flow depth and bank height. The time-dependent widening processes of two meandering channels in laboratory were selected to test the model applicability. The result showed that the simulated banklines at individual time intervals closely matched the experimental measurements.
DE: 3210 Modeling
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting