Simulating Sediment Transport in a Flume with Forced Pool-Riffle Morphology: Examinations of Two One-Dimensional Numerical Models |
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Authors: | Yantao Cui John K Wooster Jeremy G Venditti Scott R Dusterhoff William E Dietrich Leonard S Sklar |
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Affiliation: | 1Hydraulic Engineer, Stillwater Sciences, 2855 Telegraph Ave., Ste. 400, Berkeley, CA 94705 (corresponding author). E-mail: yantao@stillwatersci.com 2Geomorphologist, Stillwater Sciences, 2855 Telegraph Ave., Ste. 400, Berkeley, CA 94705. 3Assistant Professor, Dept. of Geography, Simon Fraser Univ., Burnaby, BC, V5A 1S6, Canada. 4Professor, Dept. of Earth and Planetary Science, Univ. of California, Berkeley, CA 94720. 5Assistant Professor, Dept. of Geosciences, San Francisco State Univ., San Francisco, CA 94132.
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Abstract: | One-dimensional numerical sediment transport models (DREAM-1 and DREAM-2) are used to simulate seven experimental runs designed to examine sediment pulse dynamics in a physical model of forced pool-riffle morphology. Comparisons with measured data indicate that DREAM-1 and -2 closely reproduce the sediment transport flux and channel bed adjustments following the introduction of fine and coarse sediment pulses, respectively. The cumulative sediment transport at the flume exit in a DREAM-1 simulation is within 10% of the measured values, and cumulative sediment transport at flume exit in a DREAM-2 simulation is within a factor of 2 of the measured values. Comparison of simulated and measured reach-averaged aggradation and degradation indicates that 84% of DREAM-1 simulation results have errors less than 3.3?mm, which is approximately 77% of the bed material geometric mean grain size or 3.7% of the average water depth. A similar reach-averaged comparison indicates that 84% of DREAM-2 simulation results have errors less than 7.0?mm, which is approximately 1.7 times the bed material geometric mean grain size or 11% of the average water depth. Simulations using measured thalweg profiles as the input for the initial model profile produced results with larger errors and unrealistic aggradation and degradation patterns, demonstrating that one-dimensional numerical sediment transport models need to be applied on a reach-averaged basis. |
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Keywords: | Sediment transport Numerical models Movable bed models Channel morphology Simulation |
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