Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse delta
Many deltas are threatened by accelerated soil subsidence, sea-level rise, increasing river discharge, and sediment starvation. Effective delta restoration and effective river management require a thorough understanding of the mechanisms of sediment deposition, erosion, and their controls. Sedim...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-03-01
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| Series: | Earth Surface Dynamics |
| Online Access: | https://www.earth-surf-dynam.net/6/187/2018/esurf-6-187-2018.pdf |
| _version_ | 1818839727094104064 |
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| author | E. C. van der Deijl M. van der Perk H. Middelkoop |
| author_facet | E. C. van der Deijl M. van der Perk H. Middelkoop |
| author_sort | E. C. van der Deijl |
| collection | DOAJ |
| description | Many deltas are threatened by accelerated soil subsidence,
sea-level rise, increasing river discharge, and sediment starvation.
Effective delta restoration and effective river management require a thorough
understanding of the mechanisms of sediment deposition, erosion, and their
controls. Sediment dynamics has been studied at floodplains and marshes, but
little is known about the sediment dynamics and budget of newly created
wetlands. Here we take advantage of a recently opened tidal freshwater system
to study both the mechanisms and controls of sediment deposition and erosion
in newly created wetlands. We quantified both the magnitude and spatial
patterns of sedimentation and erosion in a former polder area in which water
and sediment have been reintroduced since 2008. Based on terrestrial and
bathymetric elevation data, supplemented with field observations of the
location and height of cut banks and the thickness of the newly deposited
layer of sediment, we determined the sediment budget of the study area for
the period 2008–2015. Deposition primarily took place in channels in the
central part of the former polder area, whereas channels near the inlet and
outlet of the area experienced considerable erosion. In the intertidal area,
sand deposition especially takes place at low-lying locations close to the
channels. Mud deposition typically occurs further away from the channels, but
sediment is in general uniformly distributed over the intertidal area, due to
the presence of topographic irregularities and micro-topographic flow paths.
Marsh erosion does not significantly contribute to the total sediment budget,
because wind wave formation is limited by the length of the fetch.
Consecutive measurements of channel bathymetry show a decrease in erosion and
deposition rates over time, but the overall results of this study indicate
that the area functions as a sediment trap. The total contemporary sediment
budget of the study area amounts to 35.7×10<sup>3</sup> m<sup>3</sup> year<sup>−1</sup>, which corresponds to a net
area-averaged deposition rate of 6.1 mm year<sup>−1</sup>. This is
enough to compensate for the actual rates of sea-level rise and soil
subsidence in the Netherlands. |
| first_indexed | 2024-12-19T03:58:53Z |
| format | Article |
| id | doaj.art-96f8a17b2aab493083758077d005ba18 |
| institution | Directory Open Access Journal |
| issn | 2196-6311 2196-632X |
| language | English |
| last_indexed | 2024-12-19T03:58:53Z |
| publishDate | 2018-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Earth Surface Dynamics |
| spelling | doaj.art-96f8a17b2aab493083758077d005ba182022-12-21T20:36:44ZengCopernicus PublicationsEarth Surface Dynamics2196-63112196-632X2018-03-01618720110.5194/esurf-6-187-2018Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse deltaE. C. van der Deijl0M. van der Perk1H. Middelkoop2Faculty of Geosciences, Universiteit Utrecht, the NetherlandsFaculty of Geosciences, Universiteit Utrecht, the NetherlandsFaculty of Geosciences, Universiteit Utrecht, the NetherlandsMany deltas are threatened by accelerated soil subsidence, sea-level rise, increasing river discharge, and sediment starvation. Effective delta restoration and effective river management require a thorough understanding of the mechanisms of sediment deposition, erosion, and their controls. Sediment dynamics has been studied at floodplains and marshes, but little is known about the sediment dynamics and budget of newly created wetlands. Here we take advantage of a recently opened tidal freshwater system to study both the mechanisms and controls of sediment deposition and erosion in newly created wetlands. We quantified both the magnitude and spatial patterns of sedimentation and erosion in a former polder area in which water and sediment have been reintroduced since 2008. Based on terrestrial and bathymetric elevation data, supplemented with field observations of the location and height of cut banks and the thickness of the newly deposited layer of sediment, we determined the sediment budget of the study area for the period 2008–2015. Deposition primarily took place in channels in the central part of the former polder area, whereas channels near the inlet and outlet of the area experienced considerable erosion. In the intertidal area, sand deposition especially takes place at low-lying locations close to the channels. Mud deposition typically occurs further away from the channels, but sediment is in general uniformly distributed over the intertidal area, due to the presence of topographic irregularities and micro-topographic flow paths. Marsh erosion does not significantly contribute to the total sediment budget, because wind wave formation is limited by the length of the fetch. Consecutive measurements of channel bathymetry show a decrease in erosion and deposition rates over time, but the overall results of this study indicate that the area functions as a sediment trap. The total contemporary sediment budget of the study area amounts to 35.7×10<sup>3</sup> m<sup>3</sup> year<sup>−1</sup>, which corresponds to a net area-averaged deposition rate of 6.1 mm year<sup>−1</sup>. This is enough to compensate for the actual rates of sea-level rise and soil subsidence in the Netherlands.https://www.earth-surf-dynam.net/6/187/2018/esurf-6-187-2018.pdf |
| spellingShingle | E. C. van der Deijl M. van der Perk H. Middelkoop Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse delta Earth Surface Dynamics |
| title | Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse delta |
| title_full | Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse delta |
| title_fullStr | Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse delta |
| title_full_unstemmed | Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse delta |
| title_short | Establishing a sediment budget in the newly created “Kleine Noordwaard” wetland area in the Rhine–Meuse delta |
| title_sort | establishing a sediment budget in the newly created kleine noordwaard wetland area in the rhine meuse delta |
| url | https://www.earth-surf-dynam.net/6/187/2018/esurf-6-187-2018.pdf |
| work_keys_str_mv | AT ecvanderdeijl establishingasedimentbudgetinthenewlycreatedkleinenoordwaardwetlandareaintherhinemeusedelta AT mvanderperk establishingasedimentbudgetinthenewlycreatedkleinenoordwaardwetlandareaintherhinemeusedelta AT hmiddelkoop establishingasedimentbudgetinthenewlycreatedkleinenoordwaardwetlandareaintherhinemeusedelta |