With the expansion of hydropower, in-stream converters, flood-protection infrastructures, and growing concerns on deltas fragile ecosystems, there is a pressing need to evaluate and monitor bedform sediment mass flux. It is critical to estimate real-time bedform size and migration velocity and provide a theoretical framework to convert easily accessible time histories of bed elevations into spatially evolving patterns. We collected spatiotemporally resolved bathymetries from laboratory flumes and the Colorado River in statistically steady, homogeneous, subcritical flow conditions. Wave number and frequency spectra of bed elevations show compelling evidence of scale-dependent velocity for the hierarchy of migrating bedforms observed in the laboratory and field. New scaling laws were applied to describe the full range of migration velocities as function of two dimensionless groups based on the bed shear velocity, sediment diameter, and water depth. Further simplification resulted in a mixed length scale model estimating scale-dependent migration velocities, without requiring bedform classification or identification.
Bibliographical noteFunding Information:
The laboratory data used in this contribution were acquired by Guala et?al.?(2014) and are available at https://personal.cege.umn.edu/?guala/Michele_datasets.html (Tilting Bed Flume). Main Channel data were collected by Musa et?al.?(2018) and are available at https://hdl.handle.net/11299/203913. Colorado River data were collected by M. Kaplinski, D. Buscombe, and P. Grams with support from the Glen Canyon Dam adaptive management program administered by the U.S. Department of the Interior Bureau of Reclamation. These data are available at https://doi.org/10.5967/M02J6904 (Leary & Buscombe,?2020) Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
- mass flux