Sediment Transport: Key Research Findings Published in Limnology and Oceanography Letters
New research findings on sediment transport are published in the open access journal Limnology and Oceanography Letters. Integral coauthors are Grace Chang, Ph.D., Samuel McWilliams, E.I.T., Craig Jones, Ph.D., and Frank Spada.
The article, “Seasonal particle responses to near-bed shear stress in a shallow wave- and current-driven environment,” describes a novel method to derive characteristic shear stress from in situ acoustic and optical measurements, where characteristic shear stress is the near-bed forcing at which the rate of change to sediment concentration, size, and/or composition is most prominent. Evaluation of acoustic and optical data collected from South San Francisco Bay, California, indicate that characteristic shear stress varies seasonally and may be more important to sediment transport model parameterization than the commonly applied critical shear stress for erosion.
Scientific Significance Statement
Effective management of sediment in aquatic systems is important for many environmental and societal issues and requires accurate models of sediment transport. Accurate sediment transport models require knowledge about properties of sediment: its composition, size, and concentration in the water column. These properties change based on how much force, or shear stress, is applied to the sediment bed. We show that by investigating relationships between acoustically derived shear stress and optically derived sediment properties, we can identify a characteristic shear stress, that is, a forcing at which the rate of change to sediment properties is most pronounced. Our results show that this characteristic shear stress varies seasonally and may be more important for sediment transport models as compared to the commonly applied critical shear stress for erosion.
Chang, G., G. Egan, J.D. McNeil, S. McWilliams, C. Jones, F. Spada, S. Monismith, and O. Fringer. 2021. Seasonal particle responses to near-bed shear stress in a shallow wave- and current-driven environment. Limnol. Oceanogr. Lett. doi: 10.1002/lol2.10221.