Cargando…
Flow and wake characteristics associated with large wood to inform river restoration
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...
Autores principales: | , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8060320/ https://www.ncbi.nlm.nih.gov/pubmed/33883607 http://dx.doi.org/10.1038/s41598-021-87892-7 |
_version_ | 1783681339147419648 |
---|---|
author | Schalko, Isabella Wohl, Ellen Nepf, Heidi M. |
author_facet | Schalko, Isabella Wohl, Ellen Nepf, Heidi M. |
author_sort | Schalko, Isabella |
collection | PubMed |
description | 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. |
format | Online Article Text |
id | pubmed-8060320 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-80603202021-04-23 Flow and wake characteristics associated with large wood to inform river restoration Schalko, Isabella Wohl, Ellen Nepf, Heidi M. Sci Rep Article 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. Nature Publishing Group UK 2021-04-21 /pmc/articles/PMC8060320/ /pubmed/33883607 http://dx.doi.org/10.1038/s41598-021-87892-7 Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Schalko, Isabella Wohl, Ellen Nepf, Heidi M. Flow and wake characteristics associated with large wood to inform river restoration |
title | Flow and wake characteristics associated with large wood to inform river restoration |
title_full | Flow and wake characteristics associated with large wood to inform river restoration |
title_fullStr | Flow and wake characteristics associated with large wood to inform river restoration |
title_full_unstemmed | Flow and wake characteristics associated with large wood to inform river restoration |
title_short | Flow and wake characteristics associated with large wood to inform river restoration |
title_sort | flow and wake characteristics associated with large wood to inform river restoration |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8060320/ https://www.ncbi.nlm.nih.gov/pubmed/33883607 http://dx.doi.org/10.1038/s41598-021-87892-7 |
work_keys_str_mv | AT schalkoisabella flowandwakecharacteristicsassociatedwithlargewoodtoinformriverrestoration AT wohlellen flowandwakecharacteristicsassociatedwithlargewoodtoinformriverrestoration AT nepfheidim flowandwakecharacteristicsassociatedwithlargewoodtoinformriverrestoration |