Abstract
Tidal wetland evolution is governed by interactions between topography, vegetation, and the flow field. Aiming to provide an appropriate hydrodynamic tool within a long-term geomorphic model of vegetated wetlands, we describe an approximate procedure to model the depth-averaged flow field on vegetated intertidal platforms. The procedure is tested by a qualitative comparison with laboratory experiments and quantitatively comparing with a numerical model, focusing on the influence of spatial variations in friction on the flow field. Overall, satisfactory comparisons are obtained. Nevertheless, some limitations of the approach are apparent. These are discussed in the light of the model assumptions. We analyze the impact of the observed limitations on the ability of the approximate solution to describe the morphodynamic evolution of the bed elevation. This is performed by evaluating the changes in the bed elevation after one tidal cycle on the intertidal platform based on flow velocities obtained with a numerical model and those of the simplified procedure. It is found that the bed evolution on the platform is reasonably described with the approximate solution, even though the accumulation of sediment is underestimated near the watershed divide by the approximate model. Taking into account the computationally economic character of the approximate procedure, the analysis indicates that the model provides a suitable tool to investigate the long-term morphodynamic evolution of tidal wetlands. Key PointsAn approximate model for the flow field on intertidal platforms is discussedInfluence of advection on sediment dynamics is negligible for vegetated platformThe model is a suitable tool for long-term morphodynamic models
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1682-1703 |
| Number of pages | 22 |
| Journal | Journal of Geophysical Research: Space Physics |
| Volume | 119 |
| Issue number | 8 |
| DOIs | |
| State | Published - 2014 |
| Externally published | Yes |
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Keywords
- biogeomorphodynamics
- intertidal wetlands
- tidal flows
ASJC Scopus subject areas
- Earth-Surface Processes
- Geophysics
Cite this
An approximate solution to the flow field on vegetated intertidal platforms : Applicability and limitations. / Van Oyen, T.; Carniello, L.; D'Alpaos, A.; Temmerman, S.; Troch, Peter A; Lanzoni, S.
In: Journal of Geophysical Research: Space Physics, Vol. 119, No. 8, 2014, p. 1682-1703.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - An approximate solution to the flow field on vegetated intertidal platforms
T2 - Applicability and limitations
AU - Van Oyen, T.
AU - Carniello, L.
AU - D'Alpaos, A.
AU - Temmerman, S.
AU - Troch, Peter A
AU - Lanzoni, S.
PY - 2014
Y1 - 2014
N2 - Tidal wetland evolution is governed by interactions between topography, vegetation, and the flow field. Aiming to provide an appropriate hydrodynamic tool within a long-term geomorphic model of vegetated wetlands, we describe an approximate procedure to model the depth-averaged flow field on vegetated intertidal platforms. The procedure is tested by a qualitative comparison with laboratory experiments and quantitatively comparing with a numerical model, focusing on the influence of spatial variations in friction on the flow field. Overall, satisfactory comparisons are obtained. Nevertheless, some limitations of the approach are apparent. These are discussed in the light of the model assumptions. We analyze the impact of the observed limitations on the ability of the approximate solution to describe the morphodynamic evolution of the bed elevation. This is performed by evaluating the changes in the bed elevation after one tidal cycle on the intertidal platform based on flow velocities obtained with a numerical model and those of the simplified procedure. It is found that the bed evolution on the platform is reasonably described with the approximate solution, even though the accumulation of sediment is underestimated near the watershed divide by the approximate model. Taking into account the computationally economic character of the approximate procedure, the analysis indicates that the model provides a suitable tool to investigate the long-term morphodynamic evolution of tidal wetlands. Key PointsAn approximate model for the flow field on intertidal platforms is discussedInfluence of advection on sediment dynamics is negligible for vegetated platformThe model is a suitable tool for long-term morphodynamic models
AB - Tidal wetland evolution is governed by interactions between topography, vegetation, and the flow field. Aiming to provide an appropriate hydrodynamic tool within a long-term geomorphic model of vegetated wetlands, we describe an approximate procedure to model the depth-averaged flow field on vegetated intertidal platforms. The procedure is tested by a qualitative comparison with laboratory experiments and quantitatively comparing with a numerical model, focusing on the influence of spatial variations in friction on the flow field. Overall, satisfactory comparisons are obtained. Nevertheless, some limitations of the approach are apparent. These are discussed in the light of the model assumptions. We analyze the impact of the observed limitations on the ability of the approximate solution to describe the morphodynamic evolution of the bed elevation. This is performed by evaluating the changes in the bed elevation after one tidal cycle on the intertidal platform based on flow velocities obtained with a numerical model and those of the simplified procedure. It is found that the bed evolution on the platform is reasonably described with the approximate solution, even though the accumulation of sediment is underestimated near the watershed divide by the approximate model. Taking into account the computationally economic character of the approximate procedure, the analysis indicates that the model provides a suitable tool to investigate the long-term morphodynamic evolution of tidal wetlands. Key PointsAn approximate model for the flow field on intertidal platforms is discussedInfluence of advection on sediment dynamics is negligible for vegetated platformThe model is a suitable tool for long-term morphodynamic models
KW - biogeomorphodynamics
KW - intertidal wetlands
KW - tidal flows
UR - http://www.scopus.com/inward/record.url?scp=84921967967&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84921967967&partnerID=8YFLogxK
U2 - 10.1002/2013JF003064
DO - 10.1002/2013JF003064
M3 - Article
AN - SCOPUS:84921967967
VL - 119
SP - 1682
EP - 1703
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
SN - 2169-9380
IS - 8
ER -