Modeling Sediment Resuspension in Coastal Areas
300r--~-~--~-,--~--~-~--,
250
z 200
.),
~ 150
~
n
f5 100
50
o o'---~-~ -~--2-LOO--~--=--~-~--4--'OO
Grid number with step size of 250m
33
Fig. 6 Suspended sediment
concentrations in mgtl in
the Oder Estuary under
moderate wave climate
The concentration levels are clearly related to the higher waves and greater
water depth. Though the model needs further careful calibrations with more
field data, the agreement with known values and data images are very promising.
6
Conclusions
The new sediment transport model presented in this chapter integrates the
instantaneous vertical structure of the flow, wave-current interaction, and turbulent eddy coefficient changes due to wave/current coexistence. It is superior
to semi-empirical sediment transport models and to most other models which
are based on Bagnold's energetics concept using vertically integrated equations. It is more efficient than the fully 3D models, while all kinds of boundary
conditions for a 3D model can be used.
The new model was applied in Cleveland Bay in Australia where the model
predictions were compared with the field data during two high SSC events in
January and April 1993. The following results were achieved: (1) High concentration events of over 50 mg/l were predicted with an error less than a factor of
3. (2) Fluctuations in SSC appearing in the data, probably caused by advection
near concentration fronts, were not predicted by the model. (3) During periods
of low concentration (less than 10 mg/l), the model results were often higher
than the field data.
The preliminary model results of suspended sediment concentrations in the
Oder Estuary agree with known values and data images. However, further
model calibrations with higher quality field data is still considered necessary.
Considering the state of the art of sediment transport modeling (with model
errors of larger than one order of magnitude being quite common), the results
achieved with the new model using real data are very encouraging.
300r--~-~--~-,--~--~-~--,
250
z 200
.),
~ 150
~
n
f5 100
50
o o'---~-~ -~--2-LOO--~--=--~-~--4--'OO
Grid number with step size of 250m
33
Fig. 6 Suspended sediment
concentrations in mgtl in
the Oder Estuary under
moderate wave climate
The concentration levels are clearly related to the higher waves and greater
water depth. Though the model needs further careful calibrations with more
field data, the agreement with known values and data images are very promising.
6
Conclusions
The new sediment transport model presented in this chapter integrates the
instantaneous vertical structure of the flow, wave-current interaction, and turbulent eddy coefficient changes due to wave/current coexistence. It is superior
to semi-empirical sediment transport models and to most other models which
are based on Bagnold's energetics concept using vertically integrated equations. It is more efficient than the fully 3D models, while all kinds of boundary
conditions for a 3D model can be used.
The new model was applied in Cleveland Bay in Australia where the model
predictions were compared with the field data during two high SSC events in
January and April 1993. The following results were achieved: (1) High concentration events of over 50 mg/l were predicted with an error less than a factor of
3. (2) Fluctuations in SSC appearing in the data, probably caused by advection
near concentration fronts, were not predicted by the model. (3) During periods
of low concentration (less than 10 mg/l), the model results were often higher
than the field data.
The preliminary model results of suspended sediment concentrations in the
Oder Estuary agree with known values and data images. However, further
model calibrations with higher quality field data is still considered necessary.
Considering the state of the art of sediment transport modeling (with model
errors of larger than one order of magnitude being quite common), the results
achieved with the new model using real data are very encouraging.