Simulations in the
Scheldt estuary generated with Mike21 coupled to Ecolab
(Chemical Oceanography
and Water Geochemistry Laboratory - Université Libre de Bruxelles)
Surface
elevation of nested model
Water
current speed
Detail
of water current speed
Water
flow
Net
Primary Production
Detail
of Net Primary Production
Oxygen
exchange
Reactive-transport models that integrate
hydrodynamics with transport and transformation processes are particularly appropriate
for estimating the fluxes of reactive species in areas characterized by complex
hydrodynamic and biogeochemical behaviours, such as estuarine and coastal zones.
In particular, they can be used to analyse and predict the shift between heterotrophic
and autotrophic status within these systems, either in space (due to the existence
of C and N gradients) or in time (due to the variability of the boundary conditions
or to changes in the anthropogenic pressures). In the case of the Scheldt estuary,
we used a two-dimensional (depth-integrated) nested model (MIKE 21, DHI-Dk) together
with its newly developed water quality module (ECOLAB). In addition to salinity
and SPM, 6 variables are presently considered (degradable organic matter, O2,
NH4, NO3, Si, chlorophyll) which are involved in various processes (aerobic respiration,
nitrification, denitrification, re-aeration, gross and net primary production).