Details
| Original language | English |
|---|---|
| Pages (from-to) | 301-315 |
| Number of pages | 15 |
| Journal | Ecological engineering |
| Volume | 100 |
| Early online date | 9 Jan 2017 |
| Publication status | Published - 1 Mar 2017 |
Abstract
Vegetation-wave interactions are critical in determining the capacity of coastal salt marshes to reduce wave energy (wave dissipation), enhance sedimentation and protect the shoreline from erosion. While vegetation-induced wave dissipation is increasingly recognized in low wave energy environments, little is known about: (i) the effect of vegetation on wave dissipation during storms when wave heights and water levels are highest; and (ii) the ability of different plant species to dissipate waves and to maintain their integrity under storm surge conditions. Experiments undertaken in one of the world's largest wave flumes allowed, for the first time, the study of vegetation-wave interactions at near-field scale, under wave heights ranging from 0.1–0.9 m (corresponding to orbital velocities of 2–91 cm s−1) and water depths up to 2 m, in canopies of two typical NW European salt marsh grasses: Puccinellia maritima (Puccinellia) and Elymus athericus (Elymus). Results indicate that plant flexibility and height, as well as wave conditions and water depth, play an important role in determining how salt marsh vegetation interacts with waves. Under medium conditions (orbital velocity 42–63 cm s−1), the effect of Puccinellia and Elymus on wave orbital velocities varied with water depth and wave period. Under high water levels (2 m) and long wave periods (4.1 s), within the flexible, low-growing Puccinellia canopy orbital velocity was reduced by 35% while in the more rigid, tall Elymus canopy deflection and folding of stems occurred and no significant effect on orbital velocity was found. Under low water levels (1 m) and short wave periods (2.9 s) by contrast, Elymus reduced near-bed velocity more than Puccinellia. Under high orbital velocities (≥74 cm s−1), flattening of the canopy and an increase of orbital velocity was observed for both Puccinellia and Elymus. Stem folding and breakage in Elymus at a threshold orbital velocity ≥ 42 cm s−1 coincided with a levelling-off in the marsh wave dissipation capacity, while Puccinellia survived even extreme wave forces without physical damage. These findings suggest a species-specific control of wave dissipation by salt marshes which can potentially inform predictions of the wave dissipation capacity of marshes and their resilience to storm surge conditions.
Keywords
- Biophysical plant properties, Cauchy number, Coastal wetlands, Flow reduction, Plant breakage, Vegetation resilience, Wave dissipation, Wave flume experiment
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Engineering
- Environmental Science(all)
- Nature and Landscape Conservation
- Environmental Science(all)
- Management, Monitoring, Policy and Law
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In: Ecological engineering, Vol. 100, 01.03.2017, p. 301-315.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Vegetation-wave interactions in salt marshes under storm surge conditions
AU - Rupprecht, F.
AU - Möller, I.
AU - Paul, M.
AU - Kudella, M.
AU - Spencer, T.
AU - van Wesenbeeck, B. K.
AU - Wolters, G.
AU - Jensen, K.
AU - Bouma, T. J.
AU - Miranda-Lange, M.
AU - Schimmels, S.
N1 - Funding Information: M.P. acknowledges funding by the German Science Foundation (grant no. PA 2547/1-1). The work described in this publication was supported by the European Community’s 7th Framework Programme through the grant to the budget of the Integrating Activity HYDRALAB IV, Contract no. 261529 and by a grant from The Isaac Newton Trust, Trinity College, Cambridge. Acknowledgment: We thank all of the staff at the Großer Wellenkanal as well as B. Evans, J. Tempest, K. Milonidis and C.Edwards, Cambridge University, and D. Schulze, Hamburg University, for their invaluable logistical assistance, Fitzwilliam College for supporting the research time of I.M., and C. Rolfe, Cambridge University, for the soil analysis and Deltares for the support by the Strategic Research Programme on dikes, levees and dams.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - Vegetation-wave interactions are critical in determining the capacity of coastal salt marshes to reduce wave energy (wave dissipation), enhance sedimentation and protect the shoreline from erosion. While vegetation-induced wave dissipation is increasingly recognized in low wave energy environments, little is known about: (i) the effect of vegetation on wave dissipation during storms when wave heights and water levels are highest; and (ii) the ability of different plant species to dissipate waves and to maintain their integrity under storm surge conditions. Experiments undertaken in one of the world's largest wave flumes allowed, for the first time, the study of vegetation-wave interactions at near-field scale, under wave heights ranging from 0.1–0.9 m (corresponding to orbital velocities of 2–91 cm s−1) and water depths up to 2 m, in canopies of two typical NW European salt marsh grasses: Puccinellia maritima (Puccinellia) and Elymus athericus (Elymus). Results indicate that plant flexibility and height, as well as wave conditions and water depth, play an important role in determining how salt marsh vegetation interacts with waves. Under medium conditions (orbital velocity 42–63 cm s−1), the effect of Puccinellia and Elymus on wave orbital velocities varied with water depth and wave period. Under high water levels (2 m) and long wave periods (4.1 s), within the flexible, low-growing Puccinellia canopy orbital velocity was reduced by 35% while in the more rigid, tall Elymus canopy deflection and folding of stems occurred and no significant effect on orbital velocity was found. Under low water levels (1 m) and short wave periods (2.9 s) by contrast, Elymus reduced near-bed velocity more than Puccinellia. Under high orbital velocities (≥74 cm s−1), flattening of the canopy and an increase of orbital velocity was observed for both Puccinellia and Elymus. Stem folding and breakage in Elymus at a threshold orbital velocity ≥ 42 cm s−1 coincided with a levelling-off in the marsh wave dissipation capacity, while Puccinellia survived even extreme wave forces without physical damage. These findings suggest a species-specific control of wave dissipation by salt marshes which can potentially inform predictions of the wave dissipation capacity of marshes and their resilience to storm surge conditions.
AB - Vegetation-wave interactions are critical in determining the capacity of coastal salt marshes to reduce wave energy (wave dissipation), enhance sedimentation and protect the shoreline from erosion. While vegetation-induced wave dissipation is increasingly recognized in low wave energy environments, little is known about: (i) the effect of vegetation on wave dissipation during storms when wave heights and water levels are highest; and (ii) the ability of different plant species to dissipate waves and to maintain their integrity under storm surge conditions. Experiments undertaken in one of the world's largest wave flumes allowed, for the first time, the study of vegetation-wave interactions at near-field scale, under wave heights ranging from 0.1–0.9 m (corresponding to orbital velocities of 2–91 cm s−1) and water depths up to 2 m, in canopies of two typical NW European salt marsh grasses: Puccinellia maritima (Puccinellia) and Elymus athericus (Elymus). Results indicate that plant flexibility and height, as well as wave conditions and water depth, play an important role in determining how salt marsh vegetation interacts with waves. Under medium conditions (orbital velocity 42–63 cm s−1), the effect of Puccinellia and Elymus on wave orbital velocities varied with water depth and wave period. Under high water levels (2 m) and long wave periods (4.1 s), within the flexible, low-growing Puccinellia canopy orbital velocity was reduced by 35% while in the more rigid, tall Elymus canopy deflection and folding of stems occurred and no significant effect on orbital velocity was found. Under low water levels (1 m) and short wave periods (2.9 s) by contrast, Elymus reduced near-bed velocity more than Puccinellia. Under high orbital velocities (≥74 cm s−1), flattening of the canopy and an increase of orbital velocity was observed for both Puccinellia and Elymus. Stem folding and breakage in Elymus at a threshold orbital velocity ≥ 42 cm s−1 coincided with a levelling-off in the marsh wave dissipation capacity, while Puccinellia survived even extreme wave forces without physical damage. These findings suggest a species-specific control of wave dissipation by salt marshes which can potentially inform predictions of the wave dissipation capacity of marshes and their resilience to storm surge conditions.
KW - Biophysical plant properties
KW - Cauchy number
KW - Coastal wetlands
KW - Flow reduction
KW - Plant breakage
KW - Vegetation resilience
KW - Wave dissipation
KW - Wave flume experiment
UR - http://www.scopus.com/inward/record.url?scp=85008975798&partnerID=8YFLogxK
U2 - 10.1016/j.ecoleng.2016.12.030
DO - 10.1016/j.ecoleng.2016.12.030
M3 - Article
AN - SCOPUS:85008975798
VL - 100
SP - 301
EP - 315
JO - Ecological engineering
JF - Ecological engineering
SN - 0925-8574
ER -