Title: Quantify Wash Load and Fractional Suspended Load Transport in Lake Tahoe
Project Type: Research
Start Date: 03/01/2006
End Date: 02/29/2008
Congressional District: Nevada 02
Focus Categories: Sediments, Surface Water, Non Point Pollution
Keywords: sediment transport, hydraulics
Principal Investigator: Duan, Guohong Jennifer
Federal Funds: $8,955
Non-Federal Matching Funds: $17,909
Abstract: Silt and clay sediment particles having diameters of less than 62 µm and associated contaminants are the cause of declining clarity in Lake Tahoe. These fine particles require minimal energy for suspension and can carry large amounts of pollutants. These particles are transported as wash load and suspended load with surface runoff and stream flow and finally reach the Lake. The U.S. Geological Survey (USGS) has monitored suspended sediment in 18 tributaries at the Lake Tahoe Interagency Monitoring Program (LTIMP) sites since 1988 (Rowe et al. 2002). Concentrations of suspended sediment have been measured, but size gradations have not been determined. In order to accurately determine the sediment load that is causing turbidity in the Lake, it is necessary to separate the fine-sized silt and clay sediment from the measured suspended load. Therefore, we propose to conduct a two-year project to quantify the transport of wash load and fine suspended load carried in the tributaries discharging to Lake Tahoe.
Suspended sediment will be sampled at the LTIMP sites, and analyzed at DRI soil laboratory. Bed and bank material will also be sampled at the study sites to determine silt and clay content. Empirical relations will be formulated by using the measured data for predicting fine sediment yields. The results of this project can be applied to quantify finesized sediment and its associated pollutant load delivered to the Lake from the tributaries. The results of this study will also guide environmental managers to prioritize BMP (best management practice) projects to mitigate sediment in the Lake. Additionally, specific topics in his research will lead a graduate student from the Hydrologic Science Program at the University of Nevada, Reno to complete a thesis.
Progress/Completion Report, PDF