|Modelling of mud dynamics in the Scheldt estuary within the framework of LTV: A report submitted to the University of Budapest Technology and Economics in partial fulfilment of the Degree of MSc in Hydro-Informatics and Water Management|
Belliard, J.P.; Vanlede, J.; Mostaert, F. (2010). Modelling of mud dynamics in the Scheldt estuary within the framework of LTV: A report submitted to the University of Budapest Technology and Economics in partial fulfilment of the Degree of MSc in Hydro-Informatics and Water Management. version 2.0. WL Rapporten, 770_53. Flanders Hydraulics Research: Antwerpen. XII, 65 + 23 p. app. pp.
Part of: WL Rapporten. Waterbouwkundig Laboratorium: Antwerpen. , more
Hydraulics and sediment > Sediment > Cohesive sediment
Physics > Mechanics > Dynamics
Sediments > Clastics > Mud
ANE, Belgium, Brugge, Zeebrugge [Marine Regions]
In 2006, a work plan was conceived for the development of a mud transport model for the Scheldt estuary within the framework of LTV (Long Term Vision) (Winterwerp and De Kok, 2006). The purpose of this project is to support managers of the Scheldt estuary with the solution of a number of managerial issues. The present report discusses a part of the 2010 activites which aim at investigating on a first stage the impact of Deurganckdok (DGD) on the mud dynamics with a particular emphasis placed on the mud balance, and initialising on a second stage the setup of a detailed mud transport model for the region of Zeebrugge.
Results have shown that shifting downstream the sediment disposal location of DGD and suppressing the siltation inside the dock affects the turbidity levels in a zone extending from 70 to 90 km that is mostly situated in the Sea Scheldt where locally decrease of SSC of about 40 mg/l occur in the ETM near Antwerp. Therefore, harbour maintenance and optimisation of dredging as well as disposal strategy can have substantial benefits for the harbour of Antwerp. However, this reduction is counter balanced by an augmentation of the SSC more downstream in the Dutch-Belgian border, thus moving the problem seaward. In addition, the shift of the sediment disposal location shows limited impact on siltation rates in the neighboring harbour basins.
First stages towards the development of a mud transport model for the region of Zeebrugge have been carried out, consisting of the setup of the model supplemented by sensitivity analyses on the time-step, the boundary conditions and the settling velocity.
A valuable point is that results have revealed that the model is highly sensitive to the time-step, even more than expected. Large time-steps lead to numerical instabilities whereas small time-steps tends to reduce them although still abnormal drops in conentration occur. Defining runs with different numerical schemes may help towards fully understanding these instabilities.