Quantifying natural sediment erodibility using a mobile oscillatory flow channel

J. C. de Smit; M. G. Kleinhans; T. Gerkema; T. J. Bouma

doi:10.1016/j.ecss.2021.107574

Quantifying natural sediment erodibility using a mobile oscillatory flow channel

J. C. de Smit^*
, M. G. Kleinhans
, T. Gerkema
, T. J. Bouma

^*Corresponding author for this work

Royal Netherlands Institute for Sea Research - NIOZ
Utrecht University

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

Erosion of tidal flats is to a large degree determined by the erosion threshold of their cohesive sediments, i.e., the critical bottom shear stress identifying the onset of erosion. Given that the erodibility of tidal flats can vary strongly over both space and time, rapid in situ measuring methods for quantifying the critical bottom shear stress are needed. As the largest changes in tidal flat elevation are generally observed during storms when shear stress is wave dominated, we developed a mobile Oscillatory-Channel Resuspension flume, OsCaR, as a rapid method to measure the critical wave-generated shear stress on sediment cores directly taken from the field. We assessed the performance of the OsCaR-flume by conducting erodibility measurements on a range of artificial sand – mud mixtures, and along a natural longshore estuarine sediment type and benthic assemblage gradient. Measured erodibility of the artificial sediments matched well with sediment transport theory, indicating that the OsCaR-flume is able to reproduce wave-generated shear stress accurately. Moreover, the patterns observed in the influence of total benthic metabolic rate divided over functional groups on sediment erodibility show that the OsCaR-flume is able to capture the main benthic processes, as they corresponded well to previous laboratory based studies.

Original language	English
Article number	107574
Pages (from-to)	1-11
Journal	Estuarine, Coastal and Shelf Science
Volume	262
DOIs	https://doi.org/10.1016/j.ecss.2021.107574
Publication status	Published - 5 Nov 2021

Bibliographical note

Funding Information:
The OsCaR-flume was originally designed by Tjeerd Bouma and Bert Sinke, built by the technical workshop of the NIOZ, and tested and optimized in hydrodynamics and pneumatic control by Jaco de Smit. We thank Rob Dekker, Loran Kleine Schaars, and the students of the NCK summer school 2019 for assistance with the Mokbaai fieldwork taxonomic identification of benthos, and sediment analyses. We thank Peter van Breugel for conducting the sediment analysis of the defaunated sand-mud mixtures. All data supporting this research and scripts for determining erosion thresholds and conducted the presented analyses are available at DOI: 10.4121/14572056. For more information on building the OsCaR-flume, please contact [email protected].

Publisher Copyright:
© 2021 The Author(s)

Funding

The OsCaR-flume was originally designed by Tjeerd Bouma and Bert Sinke, built by the technical workshop of the NIOZ, and tested and optimized in hydrodynamics and pneumatic control by Jaco de Smit. We thank Rob Dekker, Loran Kleine Schaars, and the students of the NCK summer school 2019 for assistance with the Mokbaai fieldwork taxonomic identification of benthos, and sediment analyses. We thank Peter van Breugel for conducting the sediment analysis of the defaunated sand-mud mixtures. All data supporting this research and scripts for determining erosion thresholds and conducted the presented analyses are available at DOI: 10.4121/14572056. For more information on building the OsCaR-flume, please contact [email protected].

Keywords

Cohesive sediment
Erodibility
Estuary
Shear stress
Tidal flat
Waves

Access to Document

10.1016/j.ecss.2021.107574Licence: CC BY

1-s2.0-S0272771421004248-mainFinal published version, 8.47 MBLicence: CC BY

Cite this

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title = "Quantifying natural sediment erodibility using a mobile oscillatory flow channel",

abstract = "Erosion of tidal flats is to a large degree determined by the erosion threshold of their cohesive sediments, i.e., the critical bottom shear stress identifying the onset of erosion. Given that the erodibility of tidal flats can vary strongly over both space and time, rapid in situ measuring methods for quantifying the critical bottom shear stress are needed. As the largest changes in tidal flat elevation are generally observed during storms when shear stress is wave dominated, we developed a mobile Oscillatory-Channel Resuspension flume, OsCaR, as a rapid method to measure the critical wave-generated shear stress on sediment cores directly taken from the field. We assessed the performance of the OsCaR-flume by conducting erodibility measurements on a range of artificial sand {\textendash} mud mixtures, and along a natural longshore estuarine sediment type and benthic assemblage gradient. Measured erodibility of the artificial sediments matched well with sediment transport theory, indicating that the OsCaR-flume is able to reproduce wave-generated shear stress accurately. Moreover, the patterns observed in the influence of total benthic metabolic rate divided over functional groups on sediment erodibility show that the OsCaR-flume is able to capture the main benthic processes, as they corresponded well to previous laboratory based studies.",

keywords = "Cohesive sediment, Erodibility, Estuary, Shear stress, Tidal flat, Waves",

author = "\{de Smit\}, \{J. C.\} and Kleinhans, \{M. G.\} and T. Gerkema and Bouma, \{T. J.\}",

note = "Funding Information: The OsCaR-flume was originally designed by Tjeerd Bouma and Bert Sinke, built by the technical workshop of the NIOZ, and tested and optimized in hydrodynamics and pneumatic control by Jaco de Smit. We thank Rob Dekker, Loran Kleine Schaars, and the students of the NCK summer school 2019 for assistance with the Mokbaai fieldwork taxonomic identification of benthos, and sediment analyses. We thank Peter van Breugel for conducting the sediment analysis of the defaunated sand-mud mixtures. All data supporting this research and scripts for determining erosion thresholds and conducted the presented analyses are available at DOI: 10.4121/14572056. For more information on building the OsCaR-flume, please contact [email protected]. Publisher Copyright: {\textcopyright} 2021 The Author(s)",

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AU - de Smit, J. C.

AU - Kleinhans, M. G.

AU - Gerkema, T.

AU - Bouma, T. J.

N1 - Funding Information: The OsCaR-flume was originally designed by Tjeerd Bouma and Bert Sinke, built by the technical workshop of the NIOZ, and tested and optimized in hydrodynamics and pneumatic control by Jaco de Smit. We thank Rob Dekker, Loran Kleine Schaars, and the students of the NCK summer school 2019 for assistance with the Mokbaai fieldwork taxonomic identification of benthos, and sediment analyses. We thank Peter van Breugel for conducting the sediment analysis of the defaunated sand-mud mixtures. All data supporting this research and scripts for determining erosion thresholds and conducted the presented analyses are available at DOI: 10.4121/14572056. For more information on building the OsCaR-flume, please contact [email protected]. Publisher Copyright: © 2021 The Author(s)

PY - 2021/11/5

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N2 - Erosion of tidal flats is to a large degree determined by the erosion threshold of their cohesive sediments, i.e., the critical bottom shear stress identifying the onset of erosion. Given that the erodibility of tidal flats can vary strongly over both space and time, rapid in situ measuring methods for quantifying the critical bottom shear stress are needed. As the largest changes in tidal flat elevation are generally observed during storms when shear stress is wave dominated, we developed a mobile Oscillatory-Channel Resuspension flume, OsCaR, as a rapid method to measure the critical wave-generated shear stress on sediment cores directly taken from the field. We assessed the performance of the OsCaR-flume by conducting erodibility measurements on a range of artificial sand – mud mixtures, and along a natural longshore estuarine sediment type and benthic assemblage gradient. Measured erodibility of the artificial sediments matched well with sediment transport theory, indicating that the OsCaR-flume is able to reproduce wave-generated shear stress accurately. Moreover, the patterns observed in the influence of total benthic metabolic rate divided over functional groups on sediment erodibility show that the OsCaR-flume is able to capture the main benthic processes, as they corresponded well to previous laboratory based studies.

AB - Erosion of tidal flats is to a large degree determined by the erosion threshold of their cohesive sediments, i.e., the critical bottom shear stress identifying the onset of erosion. Given that the erodibility of tidal flats can vary strongly over both space and time, rapid in situ measuring methods for quantifying the critical bottom shear stress are needed. As the largest changes in tidal flat elevation are generally observed during storms when shear stress is wave dominated, we developed a mobile Oscillatory-Channel Resuspension flume, OsCaR, as a rapid method to measure the critical wave-generated shear stress on sediment cores directly taken from the field. We assessed the performance of the OsCaR-flume by conducting erodibility measurements on a range of artificial sand – mud mixtures, and along a natural longshore estuarine sediment type and benthic assemblage gradient. Measured erodibility of the artificial sediments matched well with sediment transport theory, indicating that the OsCaR-flume is able to reproduce wave-generated shear stress accurately. Moreover, the patterns observed in the influence of total benthic metabolic rate divided over functional groups on sediment erodibility show that the OsCaR-flume is able to capture the main benthic processes, as they corresponded well to previous laboratory based studies.

KW - Cohesive sediment

KW - Erodibility

KW - Estuary

KW - Shear stress

KW - Tidal flat

KW - Waves

UR - https://www.scopus.com/pages/publications/85115362712

U2 - 10.1016/j.ecss.2021.107574

DO - 10.1016/j.ecss.2021.107574

M3 - Article

AN - SCOPUS:85115362712

SN - 0272-7714

VL - 262

SP - 1

EP - 11

JO - Estuarine, Coastal and Shelf Science

JF - Estuarine, Coastal and Shelf Science

M1 - 107574

ER -

Quantifying natural sediment erodibility using a mobile oscillatory flow channel

Abstract

Bibliographical note

Funding

Keywords

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