Effect of particle size distribution on sediment loading in a mixed-land use watershed in northern Idaho /by Krzysztof Maciej Ostrowsji.

880-01The overall objective of this dissertation was to evaluate effects of particle size distribution (PSD) on sediment loads in streams with emphasis on temporal and spatial characterization of sediment loads. A methodology for determining the PSD of sediment in stream water samples using the AccuSizer 780/SIS Optical Particle Sizer was developed. High temporal resolution sampling was used to characterize the impact of sediment PSD in stream samples on the hysteretic relationship between turbidity and total suspended solids (TSS) by considering differences between the rising and falling limb of the hydrograph. Sediment loads were estimated through extensive, spatially distributed field sampling, including event-based sampling in Paradise Creek Watershed near Moscow, Idaho. Results of sediment loading using separate turbidity-TSS relationships for rising and falling limb of the hydrograph were compared to results using a single turbidity-TSS relationship.Thesis (Ph. D., Biological and Agricultural Engineering)--University of Idaho, June 2007