1. Workshop Quest4D May 14 2009 LTV-slib: Modelling of mud dynamics
Joris Vanlede (WL)
Thijs van Kessel (Deltares)
Marieke Eleveld (IVM)
Daphne van der Wal (NIOO)

2. Managerial Questions LTV slib (Long Term Vision – Mud transport)
Effects of maintenance dredging
Harbour maintenance: mostly mud
Maintenance dredging of fairway and sills: mostly sand
Effects of capital dredging
Harbour extension (e.g. Deurgancdok)
Fairway deepening and widening …
Effects on mud dynamics
Turbidity
Siltation rates
Sediment composition of tidal mud flats
Mud balance

3. Model vs. Measurements Measurements: Process-based model:
Knowledge of present condition
System knowledge
Process-based model:
Based on a physical description of processes (e.g. 3D mixing)
Quantify effects (e.g. fairway deepening, sea level rise,…)
Model output available “always” and “everywhere” (<-> monitoring)

4. Past activities 2006: 2007: 2008: Literature survey Data-analysis
Calculation of 14 days
2007:
Model improvements
Calculation of 3 months
2008:
Improvements in 3D hydrodynamics
Calculation of 1 year (seasonal dynamics)
Model application : 2nd fairway deepening

5. Hydrodynamics Year 2006 BC from ZUNO 2006 model Resolution
WS: 100m
Upstream: 30m
1 million cells in 5 layers
27 days CPU time for 1 yr. (x13)
2 TB of HD results

6. Hydrodynamics: conclusions
Calculation of 1 year of 3D hydrodynamics with measurements as boundary conditions.
Seasonal influence is modeled explicitly.
Most important difference model - measurement is M4 phase in boundary condition (action 2009).

7. Remote sensing data SPM in upper part water column (IVM)
Silt content of mud flats (NIOO)

8. IVM: SPM in de waterkolom

9. NIOO: Mud content mud flats
Mud content from radar images (SAR)
Seasonal variation in mud content

10. Seasonal dynamics Seasonal dynamics is present, but not sufficiently
Seasonal variation of settling velocity ws or erosion parameter crit
Boundary conditions are already seasonally variable

11. Import/export at Vlissingen
Gross kton/day Net
Gross export of 37 MT/yr
Gross import of 35 MT/yr
Model: Net export of 2 MT/yr
Van Alphen (1990): 0.6 MT/yr net import
Van Maldegem & Vroom (1995): 0.1 +/- 0.2 MT/yr net import

12. Validation at Antwerp
Boei Boerenschans

13. Validation at Antwerp (2)
Peak missing
Bottom concentration too low

14. ETM: Estuarine Turbidity Maximum
Neap tide Spring tide

15. Validation Remote Sensing Data

16. Validation Remote Sensing Data

17. Application: 2nd fairway deepening
1997 – 1998
7.5 m³ capital dredging works
Deepening of naturally occuring sills

18. Application: 2nd fairway deepening

19. Conclusions
Mud transport model is operational and is compared to measurements (in-situ & remote sensing)
Points of attention:
Seasonal dynamics
Estuarine circulation
M4 phase
2nd fairway deepening had little effect on SPM concentrations

20. Plans 2009 Further application of the model
Effect opening of DGD on SPM and siltation rates around Antwerp.
Effect of dumping of dredged material around Terneuzen harbor
Development of a Zeebrugge detail model
Inter-comparison between mud transport models of BMM and WL
Analysis of effects 2nd fairway deepening on siltation in harbors