Benjamin de Brye's PhD Thesis
Multiscale Finite-Element Modelling of River-Sea Continua
By Benjamin de Brye (Public Defense: Novembre 14th, 2011, 16h00, auditorium SUD11)
Coastal zones and rivers are most of the time modelled using different tools and approaches. Therefore, coupling two such models is a task that is far from trivial. With the finite-element method, unstructured meshes can be used and the spatial resolution can vary widely over the domain, making it possible to simulate river networks and the adjacent coastal zone in the same model. Investigating the feasibility thereof is one of the objectives of this thesis, in which the model utilized is SLIM, i.e. the Second generation Louvain-la-Neuve Ice-ocean Model (www.climate.be/slim).
Two applications have been developed. The first one is the Scheldt continuum (Belgium/The Netherlands) for which the grid covers the freshwater tidal river network around Ghent, the Scheldt Estuary and the whole continental shelf. The second is the Mahakam continuum (Indonesia). In this application, the domain is composed of three lakes connected to a river network that leads to a complex delta before reaching the sea.
The hydrodynamics was calibrated in the two domains and the model was used to compute the renewing timescales of the Scheldt Estuary and the Mahakam Delta. The renewing timescales such as the residence time, the exposure time and the age are measures of the rate at which the water initially in the estuary or the delta is renewed. Such diagnoses have direct links with many environmental variables and can be used to improve the understanding of the ecological dynamics inside the continuum.
| contact : Benjamin de Brye | 14/11/2011 |