HR: 0800h
AN: H21A-1315    [Abstracts]
TI: Bedload Measurements during Flood Events with Bedload Traps
AU: * Weller, J
EM: jweller@dri.edu
AF: Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512 United States
AU: * Weller, J
EM: jweller@dri.edu
AF: University of Nevada, Reno, Hydrologic Sciences Program MS/175, Reno, NV 89557 United States
AU: Duan, J
EM: gduan@dri.edu
AF: Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512 United States
AB: River restoration often requires sediment data as a fundamental design parameter. However; measuring bedload is very difficult, especially in mountain gravel-bed rivers. This research presents an application of bedload traps to measure bedload in the Spanish Creek watershed in order to assist restoration of the channel morphology/bedload equilibrium. The Spanish Creek watershed is located in the Northern Sierra Nevada in Plumas County, California. Sediment from hydraulic mining in the 1880's has been deposited in the river valley throughout the watershed, burdening the river with excess sediment. River bed sampling indicates that the bed surface is completely armored with a mean diameter of 35 mm and a much finer substrate. Bedload data were collected during the 2005 spring snowmelt using five bedload traps installed along a cross section. The traps were slightly modified from the original design by Bunte et al. to increase durability so that they could continuously sample, with regular monitoring, for the entire spring snowmelt. These data, along with historical bedload data collected with a hand-held Helley-Smith sampler, aided in selection and calibration of a surface-based fractional bedload transport model for Spanish Creek. Computer programs were written to calculate bedload transport rates, using several models, for hourly discharge intervals over the 2005 spring snowmelt season. Parker's surface-based bedload model, which provided the best fit with the measured data, was modified by taking into account the size difference between Oak Creek and Spanish Creek and because measured data indicates that highly selective transport occurs. For small mountain streams, bedload traps can be easily installed to measure bedload, but their accuracy is limited by trap dimensions, stability during high flows, accessibility for monitoring, and intensity of monitoring. Bedload transport models such as Parker's can be applied with appropriate calibration of model coefficients.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1805 Computational hydrology
DE: 1816 Estimation and forecasting
DE: 1862 Sediment transport (4558)
SC: Hydrology [H]
MN: Fall Meeting 2005