Flow and wake characteristics associated with large wood to inform river restoration
Name
s41598-021-87892-7.pdf
Description
Published version
Size
3.05 MB
Format
Adobe PDF
Checksum (MD5)
570132803c570f0b661438613bff00d4
Author(s)
Schalko, Isabella
Wohl, Ellen
Nepf, Heidi M
Date Issued
April 2021
Journal
Scientific Reports
Publisher
Springer Science and Business Media LLC
Citation
Schalko, I., Wohl, E. & Nepf, H.M. Flow and wake characteristics associated with large wood to inform river restoration. Sci Rep 11, 8644 (2021)
Version
Final published version
Abstract
Wood is an integral part of a river ecosystem and the number of restoration projects using log placements is increasing. Physical model tests were used to explore how the wood position and submergence level (discharge) affect wake structure, and hence the resulting habitat. We observed a von-Kármán vortex street (VS) for emergent logs placed at the channel center, while no VS formed for submerged logs, because the flow entering the wake from above the log (sweeping flow) inhibited VS formation. As a result, emergent logs placed at the channel center resulted in ten times higher turbulent kinetic energy compared to submerged logs. In addition, both spatial variation in time-mean velocity and turbulence level increased with increasing log length and decreasing submergence level. Submerged logs and logs placed at the channel side created a greater velocity deficit and a longer recirculation zone, both of which can increase the residence time in the wake and deposition of organic matter and nutrients. The results demonstrate that variation in log size and degree of submergence can be used as a tool to vary habitat suitability for different fish preferences. To maximize habitat diversity in rivers, we suggest a diverse large wood placement.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/S41598-021-87892-7
