HR: 1340h
AN: H53D-0488    [Abstracts]
TI: Analysis of Bedload Motion and Tranport in a Flume
AU: Castro, A
EM: amc65@humboldt.edu
AF: Humboldt State University, Environmental Resources Engineering 1 Harpst Street, Arcata, CA 95521 United States
AU: * Calderon, J
EM: jecaldero@yahoo.com
AF: Bakersfield College, 1801 Panorama Dr., Bakersfield, CA 93305 United States
AU: Cashman, E
EM: emc7001@Humboldt.edu
AF: Humboldt State University, Environmental Resources Engineering 1 Harpst Street, Arcata, CA 95521 United States
AB: The variability of bedload sediment transport rates under constant hydraulic (flow depth, flow rate, and slope) conditions and uniformly sized sediment was examined for 2mm and 4mm diameter sized sediment in a flume at Humboldt State University. Flow depth, bed height, flow rate, and velocity measurements were made for each run. A statistical analysis was used to determine the number of runs necessary to generate reliable data at each slope and discharge combination. Generally velocities, flow depths, the amount of sediment transported, and the standard deviation of the sediment transported (or the variability in sediment between runs) increased with increasing flow rate. Large variability was observed in bedload transported between runs with constant hydraulic conditions. The flume experiments suggested variation of orders of magnitude differences in bedload transport that is not explained by hydraulic parameters of average flow velocity, discharge rate, slope or water depth. Difficulties in the experiments included an observed difference between the sediment transported at the onset of water flow and the sediment transported thereafter. The results were analyzed and presented only when sediment was transported at a uniform rate. Additional observations were made to record the conditions of incipient motion. These experimental observations were compared to the Shield's diagram with good agreement. Measured sediment transport rate data was compared to predicted values using the sediment transport models proposed by a number of researchers including Meyer-Peter and Mller and Simons' Power Equation. Predictions produced percent error values between model predicted versus actual ranging from 54 % to 270 % for the sediment sizes analyzed. The bulk of this research was conducted during a summer Research Experience for Undergraduates sponsored by NSF.
DE: 1815 Erosion
DE: 1862 Sediment transport (4558)
DE: 4558 Sediment transport (1862)
SC: Hydrology [H]
MN: Fall Meeting 2005