Presentation by Marisela Des Villanueva (University of Vigo, Spain) at the Delft3D User Days, during the Delft Software Days - Edition 2023 (DSD-INT 2023). Monday, 13 November 2023, Delft.

1. 3D HYDRODYNAMIC MODELLING OF THE
GALICIAN COASTAL WATERS USING DELFT3D FM
Marisela Des
EPHYSLAB, CIM-UVIGO, Universidade de Vigo, Campus As Lagoas, Ourense, Spain
Julien Groenenboom, Ghada El Serafy
Stichting Deltares, Boussinesqweg 1, 2629 HV Delft, the Netherlands
DELFT3D USER DAYS 2023– 13 NOVEMBER

2. BACKGROUND
Study area

3. BACKGROUND
Study area

4. BACKGROUND
Study area – wind induced patterns

5. BACKGROUND
Study area – wind induced patterns

6. BACKGROUND
The Rías Baixas is a high primary productivity area.
The economy of the region depends mainly on the fishing,
shellfish gathering and aquaculture sectors.
Study area

7. BACKGROUND
Study area
Mussel
raft
polygons
Mytilus sp. ~251,000 tons in 2022 (Galician Statistics Institute).

8. BACKGROUND
Clams ~1,740 tons in 2022 (Galician Statistics Institute).
Study area

9. BACKGROUND
Setup a new model to take advantage of new possibilities offered by the Delft3D Flexible Mesh Suite (Delft3D FM)
Delft3D-FLOW (structured grid) D-Flow FM (unstructured grid)
Aim of this study

10. Horizontal grid
Based rectangular grid (2200 x 3800 m) 150x240
The resolution of the network increases with decreasing water depth
Resolution varies from ~2x3 km at open boundaries to 150x240 m
Transition in resolution using triangles
Curvilinear at selected locations
Vertical grid
20 equidistant σ-layers (47 z-layers)
MODEL SETUP - NETWORK

11. MODEL SETUP -BATHYMETRY
EMODnet Bathymetry World Base Layer (EBWBL)
High Resolution bathymetry provided by the Spanish
General Fishing Secretary
SIMULATION PERIOD
Ría de Muros
Ría de Arousa
Ría de Pontevedra
Ría de Vigo
Miño River
13 months, first month is considered spin-up

12. MODEL SETUP – BOUNDARY CONDITIONS
Open boundaries
Tide from FES2012 (33 constituents)
Water level, temperature and salinity from the Global Ocean Physics Reanalysis
(GLORYS12V1, 1/12° horizontal resolution, 50 vertical levels, daily data)
Fresh water discharges
6 most important rivers flowing in the study area from in-situ measurements
Surface forcing
Wind speed, air pressure, dew point temperature, cloud coverage, air temperature,
solar radiation and rainfall from ERA-5 (0.25° x 0.25° spatial resolution, hourly
interval)

13. MODEL RESULTS – WATER LEVELS
Amplitude (m) Phase (°)
Const Computed Observed Difference Computed Observed Difference
M2 1.149 1.141 0.008 78.465 81.473 -3.008
S2 0.411 0.399 0.012 108.303 111.45 -3.147
N2 0.245 0.241 0.004 59.581 62.879 -3.298
EPS2 0 0.01 -0.01 139.176 16.603 122.572
K2 0.112 0.113 -0.001 104.348 109.115 -4.767
K1 0.077 0.073 0.004 60.935 66.368 -5.433
NO1 0.002 0.009 -0.007 84.146 139.49 -55.344
M3 0 0.007 -0.007 226.421 312.095 -85.674
S1 0.01 0.003 0.007 207.504 203.266 4.238
M6 0.005 0.005 0 56.925 141.464 -84.539
Computed Observed Difference
Vilagarcia2

14. MODEL RESULTS – SALINITY AND TEMPERATURE
Preliminary results!
Computed Observed
Cortegada

15. MODEL RESULTS – SALINITY (DOWNWELLING)
Preliminary results!

16. MODEL RESULTS – SALINITY (DOWNWELLING)
Preliminary results!

17. MODEL RESULTS – TEMPERATURE (DOWNWELLING)
Preliminary results!

18. MODEL RESULTS – SALINITY (UPWELLING)
Preliminary results!

19. MODEL RESULTS – TEMPERATURE (UPWELLING)
Preliminary results!

20. CONCLUSIONS
- Using Delft3D FM’s unstructured grid allows improving the resolution in areas of interest where it is needed
- Good agreement between observed and modelled tide and water levels
- The preliminary model validation shows satisfactory results regarding general transport patterns.
- Next steps:
• Improve the horizontal spreading and vertical mixing of salinity and temperature
• Evaluate the model’s capability to reproduce currents
• Coupling between D-Flow FM and D-Particle Tracking

21. Grazas!
Marisela Des - mdes@uvigo.gal
Thank you!