Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 16, 2018 | Published + Supplemental Material
Journal Article Open

Intense Granular Sheetflow in Steep Streams

Abstract

Quantifying sediment transport rates in mountainous streams is important for hazard prediction, stream restoration, and landscape evolution. While much of the channel network has steep bed slopes, little is known about the mechanisms of sediment transport for bed slopes between 10% < S < 30%, where both fluvial transport and debris flows occur. To explore these slopes, we performed experiments in a 12‐m‐long sediment recirculating flume with a nearly uniform gravel bed. At 20% and 30% bed gradients, we observed a 4‐to‐10 particle‐diameter thick, highly concentrated sheetflow layer between the static bed below and the more dilute bedload layer above. Sheetflow thickness increased with steeper bed slopes, and particle velocities increased with bed shear velocity. Sheetflows occurred at Shields stresses close to the predicted bedload‐to‐debris flow transition, suggesting a change of behavior from bedload to sheetflow to debris flow as the bed steepens.

Additional Information

© 2018 American Geophysical Union. Received 8 FEB 2018; Accepted 22 MAY 2018; Accepted article online 29 MAY 2018; Published online 9 JUN 2018. Funding was provided to M. P. L. by the National Science Foundation grant EAR‐1346115 and EAR‐1558479 and to M. C. P. by a National Science Foundation Postdoctoral Fellowship EAR‐1452337. We thank Samuel Holo, Brian Zdeb, and Erich Herzig for the help with setting up the experiments, collecting data, and calibrating instruments. We thank Francois Ayoub for the help with developing the OpenCV python script used for dense optical flow particle tracking, and Kimberly Hill for insightful discussions. The experimental data are provided in the supporting information.

Attached Files

Published - Palucis_et_al-2018-Geophysical_Research_Letters.pdf

Supplemental Material - grl57503-sup-0001-2018gl077526-si.docx

Supplemental Material - grl57503-sup-0002-2018gl077526-ts01.xlsx

Supplemental Material - grl57503-sup-0003-2018gl077526-ms01.avi

Files

Palucis_et_al-2018-Geophysical_Research_Letters.pdf
Files (72.7 MB)
Name Size Download all
md5:915ab5cb630dd946f0bd7a075d49b42b
71.7 MB Download
md5:bac4dcc6c54754108f11f2c519c2db13
831.8 kB Preview Download
md5:1a34c52ffd556f78ecf29491eb562a2e
201.0 kB Download
md5:e8ddbeb4e3918f2327bbafcd54167634
37.1 kB Download

Additional details

Created:
August 22, 2023
Modified:
October 18, 2023