Reclamation of tidal flats within tidal basins alters centennial morphodynamic adaptation to sea‐level rise
Reclamation of tidal flats within tidal basins alters centennial morphodynamic adaptation to sea‐level rise
Reclamation of low-lying tidal flats and floodplains adjacent to present shorelines has been implemented worldwide for both coastal defense and development. While it is technically feasible to monitor the short-term impact of tidal flat embankments, it is challenging to identify long-term and cumulative morphodynamic impact, particularly considering centennial sea-level rise (SLR). In this study, we construct a process-based hydro-morphodynamic model for a schematized tidal basin and examine its morphodynamic evolution under the combined influence of SLR and tidal flat embankments. We see that rising sea levels lead to inundation of low-lying floodplains just above high water, creating new intertidal flats that mitigate the drowning impact of SLR. This mitigation effect is lost if the low-lying floodplains and tidal flats are reclaimed, preventing any shoreline migration under SLR. Removing a large portion of intertidal flats within the tidal basin induces significant changes in basin hypsometry and potentially, a reversal of flood/ebb dominance. The resulting hydro-morphodynamic impact of large-scale tidal flat embankment is more significant than SLR at a centennial time scale. This suggests a need for much greater management awareness regarding the cumulative impact of human activities. These findings imply that allowing lateral shoreline migration under SLR sustains tidal basin's inherent morphodynamic buffering capacity, whereas reclaiming tidal flats significantly alters hydro-morphodynamic adaptation at the decadal to centennial time scales. It highlights the importance of conserving low-lying floodplains and tidal flats in tide-dominated systems to counteract the drowning impact of SLR.
embankment, morphodynamic modeling, sea-level rise, tidal basin
Guo, Leicheng
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Zhu, Chunyan
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Xu, Fan
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Xie, Weiming
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Van Der Wegen, Mick
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Townend, Ian
f72e5186-cae8-41fd-8712-d5746f78328e
Wang, Zheng Bing
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He, Qing
94baedd4-45f0-436e-83d4-4e2ebcd1bec3
June 2022
Guo, Leicheng
713f7dde-d88a-4f2c-9c66-7f9c6978ceb0
Zhu, Chunyan
3b539a8b-319a-4662-aa39-7b4eab164acb
Xu, Fan
a74a50aa-98c4-4457-a767-f0fe8820c535
Xie, Weiming
e10c4755-09a9-4f68-9570-3345bfbca021
Van Der Wegen, Mick
d2a102db-0ab2-4563-a437-3f11f230d2c7
Townend, Ian
f72e5186-cae8-41fd-8712-d5746f78328e
Wang, Zheng Bing
0bf73ba6-eed4-4ebe-8175-929d35912e3d
He, Qing
94baedd4-45f0-436e-83d4-4e2ebcd1bec3
Guo, Leicheng, Zhu, Chunyan, Xu, Fan, Xie, Weiming, Van Der Wegen, Mick, Townend, Ian, Wang, Zheng Bing and He, Qing
(2022)
Reclamation of tidal flats within tidal basins alters centennial morphodynamic adaptation to sea‐level rise.
Journal of Geophysical Research: Earth Surface, 127 (6), [e2021JF006556].
(doi:10.1029/2021JF006556).
Abstract
Reclamation of low-lying tidal flats and floodplains adjacent to present shorelines has been implemented worldwide for both coastal defense and development. While it is technically feasible to monitor the short-term impact of tidal flat embankments, it is challenging to identify long-term and cumulative morphodynamic impact, particularly considering centennial sea-level rise (SLR). In this study, we construct a process-based hydro-morphodynamic model for a schematized tidal basin and examine its morphodynamic evolution under the combined influence of SLR and tidal flat embankments. We see that rising sea levels lead to inundation of low-lying floodplains just above high water, creating new intertidal flats that mitigate the drowning impact of SLR. This mitigation effect is lost if the low-lying floodplains and tidal flats are reclaimed, preventing any shoreline migration under SLR. Removing a large portion of intertidal flats within the tidal basin induces significant changes in basin hypsometry and potentially, a reversal of flood/ebb dominance. The resulting hydro-morphodynamic impact of large-scale tidal flat embankment is more significant than SLR at a centennial time scale. This suggests a need for much greater management awareness regarding the cumulative impact of human activities. These findings imply that allowing lateral shoreline migration under SLR sustains tidal basin's inherent morphodynamic buffering capacity, whereas reclaiming tidal flats significantly alters hydro-morphodynamic adaptation at the decadal to centennial time scales. It highlights the importance of conserving low-lying floodplains and tidal flats in tide-dominated systems to counteract the drowning impact of SLR.
Text
Reclamation of Tidal Flats Within Tidal Basins Alters Centennial Morphodynamic
- Accepted Manuscript
More information
e-pub ahead of print date: 17 June 2022
Published date: June 2022
Additional Information:
Funding Information:
This work is financially supported by the Ministry of Science and Technology, P.R. China (MOST) (No. 2016YFE0133700) and Royal Netherlands Academy of Arts and Sciences (KNAW) (No. PSA‐SA‐E−02), and also partly by Natural Science Foundation of China (Nos. 51739005, U2040216, 41876091), and Shanghai Committee of Science and Technology (No. 20DZ1204700).
Publisher Copyright:
© 2022. American Geophysical Union. All Rights Reserved.
Keywords:
embankment, morphodynamic modeling, sea-level rise, tidal basin
Identifiers
Local EPrints ID: 468535
URI: http://eprints.soton.ac.uk/id/eprint/468535
ISSN: 2169-9003
PURE UUID: 5763ed44-b657-4889-a4c1-89a884e5f39c
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Date deposited: 17 Aug 2022 17:02
Last modified: 17 Mar 2024 02:54
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Contributors
Author:
Leicheng Guo
Author:
Chunyan Zhu
Author:
Fan Xu
Author:
Weiming Xie
Author:
Mick Van Der Wegen
Author:
Zheng Bing Wang
Author:
Qing He
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