Dear all, I've a question relating to difference between
temperature as a process in hydro module and water temperature
as a substance in delwaq module. what is the difference and
which is preferred to use? I also need to know about the
downstream boundary in WQ module. Is it right that my model does
not follow the d.s. boundary concentrations and I change the
concentrations within the domain myself to achieve the boundary
characteristics or something might be wrong? thanks in advance!
The preference for modelling temperature in Delft3D-FLOW or
Delft3D-WAQ really depends on why you need it:
- Delft3D-WAQ does not take the interaction with the flow field into
account, such as stratification and density driven flows - as it does
not calculate the flow field. FLOW does do that.
- Delft3D-WAQ can either calculate the temperature as a substance or
it can import the temperature results from Delft3D-FLOW. The water
temperature is a factor in many water quality processes, so it may be
of importance indeed.
- The modelling of temperature in Delft3D-WAQ is fairly simple (at
least as far as the basic implementation is concerned). Anything more
sophisticated probably is best done via Delft3D-FLOW. The basic
implementation is meant for such things as the temperature differences
due to thermal pollution, not so much the warming and cooling of a
water body under influence of the meteorology (a more sophisticated
module exists but is not documented, unfortunately)
As for downstream boundary conditions: the equations solved by
Delft3D-WAQ are such that these play a minor role only. You can even
turn off the influence by setting the dispersion on the boundaries to
zero. This is useful because the influence is limited to upstream
diffusion/dispersion. Note: this is quite different from hydrodynamic modelling.
If you want to pick up the temperature as calculated by the FLOW
module, then it should be a segment function in Delft3D-WAQ, so indeed
a process parameter and not a substance.
thanks Arjen for your time and effort. But I think you didn't get me
well. My point is; I need to study the effect of temperature on WQ
substances not to pick up the temperature itself. The Temperature is
simulated on FLOW module and I need to import it to WAQ input file.
Does the online coupling do that or there's another step that I should make?
The coupling from FLOW should produce a .tem-file together with the
hyd-file. In the old user interface you will have to pick that up
manually. So in the PLCT you will need to set the 'Temp' that is input
for many processes to an editable parameter (you only need to do that
for one of these processes, they will then all see it as an editable parameter).
In the old user interface, then go to the process parameters, click
in the field for Temp, end press the Edit Data button. In Properties -
Details, switch to Scalar Field. After that, go to Data - Import.
Switch the file type to Delft3D-WAQ segment function, and select the
.tem-file. You can do the same with salinity and bottom sheer stress
if you need that from FLOW as well.