Development of a sixth generation Scheldt estuary model: model setup, calibration and validation
Vanlede, J.; Zijlker, T.; Nazarali, M.; van der Kaaij, T.; Sumihar, J. (2024). Development of a sixth generation Scheldt estuary model: model setup, calibration and validation. Version 0.5. Deltares: Delft. 131 pp. | |
| Available in | Authors | | Document type: Project report
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| Keywords | Hydraulics and sediment > Hydrodynamics > Tides
Numerical modelling
ANE, Netherlands, Westerschelde [Marine Regions]; Belgium, Schelde R. [Marine Regions]
| | Author keywords | D-HYDRO; zesde-generatie; 3D; modelschematisatie |
| Project | Top | Authors | - Opmaak 6e generatie Scheldemodel in D-Hydro FM, more
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Contact detailsProposer: Ministerie van Infrastructuur en Milieu; Rijkswaterstaat; Water, Verkeer en Leefomgeving (WVL) , more
| Authors | | Top | - Vanlede, J., more
- Zijlker, T.
- Nazarali, M., more
| - van der Kaaij, T., more
- Sumihar, J.
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| Abstract | This report describes the setup, calibration and validation of a 3D sixth-generation model schematisation of the Scheldt estuary with the D-HYDRO Suite software called dflowfm3d-schelde_nevla-j19_6-v3a. This model schematisation concerns a 3D model as its main intended use is as a base model for applications in morphology, silt and sediment transport, water quality and ecology. The present report only presents the hydrodynamic part (water level, currents, salinity).
Development of this model was done in cooperation between Deltares and Flanders Hydraulics. This is part of more extensive cooperation in the Flemisch-Dutch Scheldt Committee (VNSC).
The modelled domain covers part of the southwestern North Sea around the Scheldt estuary between Gravelines (France) and Domburg (Netherlands), with a seaward distance of about 40 km and the whole Scheldt estuary including its tributaries.
The geographical database Baseline was used for the model setup. A specific Baseline tree was created for the Scheldt estuary model: baseline-schelde_nevla-j19_6-v3. The model is built with data available at the start of the year 2019.
After the development of the initial model schematization, uncertainties in the initial bed roughness were reduced in a calibration procedure. The model was calibrated in a calm period from June 15th until July 15th 2018. Calibration factors for the roughness of 16 areas that cover the summer bed of the model domain were optimised one by one, following the thalweg in the upstream direction.
Validation of the results over the year 2018 and different sub-periods of that year indicates that the model provides robust quality with an average water level RMSE of 7.8 cm in the coastal area, 10.1 cm in the Western Scheldt and 17.6 cm in the Sea Scheldt. Current velocities are modelled with good quality at fixed velocity stations but worse at (shallow) temporary velocity measurement stations. Comparison to the sailed 19 ADCP campaign shows reasonable to good quality of the simulated current magnitude and directions at different sailed tracks in the Western Scheldt. Crosscurrents due to large eddies around the Ossenisse shoal are not predicted correctly. Temporal variation of salinity is captured well (standard deviation <2 psu), however, average salinity levels are overestimated in the Western Scheldt and Sea Scheldt (on average 5 psu). |
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