A mixed length scale model for migrating fluvial bedforms

Geophysical Research Letters
By: , and 



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.

Publication type Article
Publication Subtype Journal Article
Title A mixed length scale model for migrating fluvial bedforms
Series title Geophysical Research Letters
DOI 10.1029/2019GL086625
Volume 47
Issue 15
Year Published 2020
Language English
Publisher American Geophysical Union
Contributing office(s) Southwest Biological Science Center
Description e10.1029/2019GL086625, 10 p.
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