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Light extinction due to DOC

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Ingrid Holzwarth, modified 5 Years ago.

Light extinction due to DOC

Youngling Posts: 10 Join Date: 10/24/12 Recent Posts
Dear Delwaq-Forum,

I use the DYNAMO-module to simulate algae growth and activate the radiation-limitation function. Therefore, the total extinction coefficient has to be calculated.

If I use th GUI, I can choose different specific attenution coefficients which are multiplied by the concentration of the specific substance (e.g. Diatoms or POC1) to result in a contribution to the total extinction coefficient.
However, I don't find a possibilty to choose a specific coefficient for DOC and my results for ExtVlODS (which should contain the partial attenuation due to DOC) contain only zeros.
Do I have to activate this part separately from the other partial attenuations?

Best regards,
Ingrid
Mathieu Chatelain, modified 5 Years ago.

RE: Light extinction due to DOC

Padawan Posts: 28 Join Date: 12/13/12 Recent Posts
Dear Ingrid,
I was also, surprisingly, not able to activate the extinction coefficient for DOC using the GUI. I'll keep looking because it has to be there, somewhere, in the process library of DelWAQ.

In the meantime, it is possible to force it. You should add it by manually editing your input file (in block 7), with something like:
CONSTANTS ExtVlDOC DATA 0.4
You can then check in the LST and LSP-files that it is read and activated correctly, and then in your output file that is indeed contributing to ExtVLODS.

Just as a reminder, be aware that every time you save your work with the GUI, the input file will be overwritten (and your manual changes will be erased).

Hope this helps,
-Mathieu.
Michel Jeuken, modified 5 Years ago.

RE: Light extinction due to DOC

Jedi Knight Posts: 156 Join Date: 1/21/13 Recent Posts
Hi Ingrid,

I see no reason why it should be an hidden option, so I changed some flags. This version of the proc_def should make it available in the PLCT. You can replace it in your Delft3D installation, usually somewhere in c:\Program Files (x86)\Deltares\Delft3D 4.01.00\win32\waq\bin\.


greetings,
Michel

P.S.: Another work around (in case you need an other hidden parameter or output) would be to add the parameter to the sub-file, see an example below. This way you can still use the delwaq GUI. However, you can't load the substance file into the PLCT, so if you update your model with the PLCT, you need to add your manual changes to the sub-file again.

parameter 'RcMrtEColi'
description 'first-order mortality rate EColi'
unit '(1/d)'
value 0.8000E+00
end-parameter