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space varying time dependent input data

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Gisli Petursson, modified 4 Years ago.

space varying time dependent input data

Youngling Posts: 4 Join Date: 4/26/13 Recent Posts
I have two problems regarding space varying, time dependent input of processes in the Delft Water Quality input files. I’m using the GUI to generate my input files.

The first problem is in regards to space varying time dependent wind speed in the Delft Water Quality process RearOXY. I’ve managed to make meteo files that work in Flow, I included them under the additional parameters tab (under the Flow GUI) with the flags Filwp, Filwu and Filwv as shown in the Delft3D-Flow user manual and the Flow simulation ran without problems. However I don’t see any obvious ways to include space varying time dependent wind in the WAQ GUI. From the process library configuration tool I can select between “constant” or “meteo” for the wind speed (VWind) under RearOxy, if I select the meteo option I can only include 5 meteo stations but not a velocity field such as in Flow. If I select the constant option I can make the wind constant in time and space, timeseries (but not space varying) or Scalar field (which is not time dependent) under the Process parameters tab in the WAQ GUI.
My question is, can I use the same wind field (or similar meteo file) for Flow and for WAQ? If so, how am I able to include the wind velocity file(s) in WAQ?

The second problem is in regards to space varying time dependent BOD and/or COD load in the process WAQ process BODCOD. My model covers large area and long time, I want to define different COD load dependent on time and space, is there any way to make a file (e.g. similar file to the meteo wind file mentioned in question 1, except for COD or BOD) that defines the space and time varying loads for WAQ?

Any advice to point me in the right direction is highly appreciated.

Thanks in advance.
Gisli
meteo file wind meteo delwaq - water quality processes wind files water quality meteofile space varying wind process library
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Gisli Petursson, modified 4 Years ago.

RE: space varying time dependent input data

Youngling Posts: 4 Join Date: 4/26/13 Recent Posts
After reading the section on Process parameters in the D-Water_Quality User manual better I see that it is stated that
By default the process parameters will be constant in time and space. However, process parameters can vary in time and/or space.

which gave me hope that I could have my input data vary in time and space, however in the "import data file" section it states
Non-uniform values can be imported from an external ?le. Non-uniform values can be time-series or spatially varying.

So I guess that is my answer, I'm limited by 5 meteo stations and constant load in time or space. However I think this is an strange, since I'm able to run Flow and WAQ coupled I would think it would be logical that I could use the same wind field as the input for both solvers.

I will leave this open as unanswered in hope that someone will correct me and point me in the right direction of some clever way to import time and space varying wind and/or load data (or confirm that my understanding from above is correct).

- Gisli
Christophe Thiange, modified 4 Years ago.

RE: space varying time dependent input data (Answer)

Jedi Knight Posts: 125 Join Date: 11/15/12 Recent Posts
Hi Gisli,

It is perfectly possible to use space and time varying input for any parameter. In DELWAQ terminology this is called a segment function.

In the DELWAQ GUI, go to Process Parameters, click the text box of the relevant parameter and then the Edit Data button. A new window appears. Go to Properties > Details and select Scalar field and click OK. Go to Data > Import, select the file type you want to use and browse to your data file.

To specify data or data files directly in the input file see section 7 of the Input File Description Manual.

The problem you may run into for your wind input is that the wind input files used by FLOW are not directly usable by DELWAQ. I am not sure if the direct coupling generates a com-*.* file with wind velocities when FLOW is run with space varying wind. I'll confirm that later, but if it does not, that would be a nice improvement.

Regarding BODCOD, I understand you are modelling BOD and COD and want to have space and time varying loads over all your domain. You may have no other choice than having to reformat your original data into separate time series for each individual (surface) segment. This may sound like a lot of work but if you are handy with whatever scripting language the task is relatively easy. You can use the DELWAQ GUI or QUICKPLOT to see the DELWAQ segment numbers. You can then use those numbers to specify your COD/BOD loads as described in section 6 of the Input File Description Manual.

Hope this helps.
GP
Gisli Petursson, modified 4 Years ago.

RE: space varying time dependent input data

Youngling Posts: 4 Join Date: 4/26/13 Recent Posts
Christophe,

Thank you for your reply, this was exactly what I was looking for.

Regards,
Gisli