Abstract
Worldwide, many tidal basins associated with barrier coasts have infilled over the past millennia due to the combination of sediment supply, wave-tidal sediment transport, and eco-engineering effects of vegetation. However, the biogeomorphological interactions between saltmarsh and the morphodynamics of an entire coastal barrier system are poorly understood, especially under sea level rise (SLR). Here, we study the evolution of a barrier coast for combinations of mud availability, presence of vegetation, and SLR. We developed a novel biogeomorphological model of an idealized barrier coast enclosing a tidal basin with sandy-clayey sediments that was subjected to tides and waves for a century. The morphodynamic Delft3D model was coupled to a vegetation code which accounts for the dynamics of marsh-type vegetation. Initially, vegetation contributed to reducing the tidal prism while sediment was imported. However, with SLR this trend was reversed and the tidal basins started to export sediment for vegetated runs after about 50–60 years while the unvegetated scenarios continued to infill in pace with the SLR. The sediment export was caused by cascading biomorphodynamic feedback effects triggered by vegetation which modified channel and shoal dynamics. Even under higher mud supply, the SLR resulted in vegetation collapse. The hypsometries, similar to natural systems, showed that vegetated systems converge to an alternative stable state condition. We conclude that the long-term resilience of the tidal basin associated with sediment infilling under SLR can be reduced by cascading large-scale effects of vegetation on the morphodynamics of barrier coasts.
| Original language | English |
|---|---|
| Article number | e2022JF006703 |
| Number of pages | 22 |
| Journal | Journal of Geophysical Research: Earth Surface |
| Volume | 128 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2023 |
Bibliographical note
Publisher Copyright:© 2023. The Authors.
Funding
Supported by ERC Consolidator Grant 647570 to MGK. The computer resources were further supported by NWO-SurfSARA project 17635, and the Geosciences Eejit cluster at Utrecht University. The authors acknowledge the assistance from Edwin Sutanudjaja (UU), Lukas van de Wiel (UU), and Maxime Moge (SurfSARA) to compile and run Delft3D in the HPC Linux clusters and João Dobrochinski (Deltares) for the guidance with the Mormerge parallelization. We thank the reviewers, including Brad Murray, for their commitment and engagement to our article through constructive and challenging comments that highly improved the final article. We are thankful to Harm Jan Pierik for the fruitful geological discussions. We further acknowledge Ana Rita Carrasco and Óscar Manuel Fernandes Cerveira Ferreira from Universidade do Algarve for sharing recent complementary bathymetric data from the Ria Formosa, PT. Supported by ERC Consolidator Grant 647570 to MGK. The computer resources were further supported by NWO‐SurfSARA project 17635, and the Geosciences Eejit cluster at Utrecht University. The authors acknowledge the assistance from Edwin Sutanudjaja (UU), Lukas van de Wiel (UU), and Maxime Moge (SurfSARA) to compile and run Delft3D in the HPC Linux clusters and João Dobrochinski (Deltares) for the guidance with the Mormerge parallelization. We thank the reviewers, including Brad Murray, for their commitment and engagement to our article through constructive and challenging comments that highly improved the final article. We are thankful to Harm Jan Pierik for the fruitful geological discussions. We further acknowledge Ana Rita Carrasco and Óscar Manuel Fernandes Cerveira Ferreira from Universidade do Algarve for sharing recent complementary bathymetric data from the Ria Formosa, PT.
| Funders | Funder number |
|---|---|
| European Research Council | 647570, 17635 |
Keywords
- biomorphodynamics
- eco-engineering
- equilibrium state
- morphology
- sediment transport
- tidal basin