Open Collections

Xing, Tianqi

University of British Columbia

This study utilizes tracer data spanning a 12-year period from a small gravel-bed stream to investigate sediment burial depth and distribution in relation to key controls, including flow shearing work (expressed as time-integrated excess flow energy expenditure, ΩT), bedload grain size, and channel morphology. Higher ΩT leads to increased vertical mixing, especially among moved tracers, which tend to fit exponential and Gamma distributions, with the distribution shape is influenced by ΩT . Tracers with smaller grain sizes exhibit deeper and more dispersed burial, while coarser materials tend to concentrate near the bed surface. The central tendency of burial depth shows a notable negative correlation with grain size, particularly in larger size classes. Bed morphology doesn’t strongly impact the average burial depth, but it does cause different burial patterns. Deeper sediment burial is found in sidebars and pools, suggesting different levels of vertical mixing. Results of this study allow for the description of the role of flow, bed material grain size, and bed morphology on vertical sediment dispersion in a low sediment transport regime channel. Generalizing these findings requires further analysis in diverse fluvial systems. Any extrapolation requires a careful and justified scaling approach, acknowledging the study’s site-specific nature.

Text

2024-03-07

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87533

Geography

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/