Environmental Engineering Reference
In-Depth Information
of accuracy and stability. Here, the hydrodynamic
equations are solved with a central approximation
for second-order accuracy and an implicit scheme.
The solution is performed over the southernNorth
Sea area shown in Figure 16.4.
Larson et al. 1997; Van Goor et al. 2001;
Karunarathna and Reeve 2008). Predictions can
be made on the basis of parameterizing all but a
few processes as a source function. These models
have had reasonable success in predicting changes
in morphology but there is no established method
for defining the parameterization.
Model set-up
The openboundary in the south is located between
Rye in England and Cap Gris Nez in France. The
open boundary in the north is located between
Flamborough Head in England and Norderney in
Germany. The bed elevations vary between 2m
above Chart Datum (CD) and 95m below CD in
Silver Pit in front of the Humber Estuary. The sea
bottom shows different forms and features includ-
ing sand waves up to 16m high. There are also
numerous tidal sandbanks in the area (e.g. the
Norfolk, Great Yarmouth, Flemish and Zeeland
Banks).
The selection of the boundary conditions sat-
isfied the requirement that there are some tidal
stations that can provide data for comparison with
the results obtained by the model. The digital
Case study: Tidal Flow Prediction
A tidal flow model, developed by Osment (1992)
and based on the approach of Falconer (1976), is
used to calculate the tidal flow in the southern
North Sea. This model simulates unsteady two-
dimensional flows in one-layer (vertically homo-
geneous) fluids.
The numerical model uses the finite difference
Alternating Direction Implicit (ADI) technique to
integrate the equations for mass and momentum
conservation. This method is a well-proven tech-
nique that has the ability to handlemoving bound-
aries. There are various implementations of the
finite difference method that give different levels
Fig. 16.4
Model domain and southern North Sea bathymetry in the UK National Grid reference system digitized
from the Admiralty Chart No. 2182A showing the position of the calibration and validation points.
