A finite-element, multi-scale model of the Scheldt tributaries, river, estuary and ROFI
de Brye, B.; de Brauwere, A.; Gourgue, O.; Kärnä, T.; Lambrechts, J.; Comblen, R.; Deleersnijder, E. (2010). A finite-element, multi-scale model of the Scheldt tributaries, river, estuary and ROFI. Coast. Eng. 57(9): 850-863. dx.doi.org/10.1016/j.coastaleng.2010.04.001
In: Coastal Engineering: An International Journal for Coastal, Harbour and Offshore Engineers. Elsevier: Amsterdam; Lausanne; New York; Oxford; Shannon; Tokyo. ISSN 0378-3839; e-ISSN 1872-7379, more
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| Keywords |
Finite elements
Models
Motion > Tidal motion > Tides
Physics > Mechanics > Fluid mechanics > Hydrodynamics
Properties > Chemical properties > Salinity
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| Author keywords |
Finite-element; Model; Scheldt Estuary; Tide; Hydrodynamics; Multi-scale; Salinity; Lagrangian residual velocity |
| Abstract |
We report on the development and validation of a coupled two- and one-dimensional finite-element model for the Scheldt tributaries, River, Estuary and region of fresh water influence (ROFI). The hydrodynamic equations are solved on a single, unstructured, multi-scale mesh stretching from the shelf break to the Scheldt tributaries. The tide is forced on the shelf break and propagates upstream in the riverine network. Upstream boundaries lie on sluices or outside of the region of tidal dominance where daily averaged discharges are imposed. Two-dimensional, depthaveraged shallow water equations are solved by means of the discontinuous Galerkin (DG) method over the marine and estuarine parts of the computational domain. In the rivers, however, one-dimensional equations are dealt with using the DG method with the addition of a technique to cope with confluence points. Model parameters are carefully calibrated, leading to the simulation of wind- and tide-forced flows that are in excellent agreement with available data. The diffusivity in the transport equation is calibrated using timeseries of salinity at various locations in the estuary. Finally, the Lagrangian residual transport in the estuary an the adjacent coastal zone is investigated. This work is a major step towards an integrated model for studying the dynamics of waterborne contaminants and the water renewal timescales in the Scheldt land-sea continuum. |
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