Now sure how to update a model parameter and the print time value

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Hydraus_1d_RD
Posts: 16
Joined: Thu Dec 17, 2020 10:11 pm
Location: USA

Now sure how to update a model parameter and the print time value

Post by Hydraus_1d_RD » Tue Jan 05, 2021 7:04 pm

Dear all,
I’m presently trying to figure out how to do two following things in Hydrus-1D:
1) Change the With Air-Entry value of –2 cm (default) to some other value (e.g.,-5 cm). Would you please let me know if you have any suggestions?
2) I need mass balance results on daily time steps for my model that runs for six years. When I use the number of print times higher than 250, Hydrus results error. Would you please let me know if there are any ways to increase the lime to very high values such as 2190 (=365*6)?
Thank you!
Sincerely,
A Hydrsu-1D user

Jirka
Posts: 5216
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Now sure how to update a model parameter and the print time value

Post by Jirka » Tue Jan 05, 2021 8:44 pm

You can get different air-entry values if you use the modified van Genuchten model and manipulate the Theta_m (>Theta_s) parameter.

The GUI allows only 250 print times. The computational module is dimensioned for 100 print times. If you want to have more than 250, but less than 1000, print times, you need to manually edit the Selector.in file.

J.

Hydraus_1d_RD
Posts: 16
Joined: Thu Dec 17, 2020 10:11 pm
Location: USA

Re: Now sure how to update a model parameter and the print time value

Post by Hydraus_1d_RD » Wed Jan 06, 2021 8:48 pm

Thank you, Jirka. As I need daily time step mass balance info for three years (total days=1095), I am slightly above the 1000 cutoff value. Would you please let me know if there is any possibility to extend the cutoff value any further to a very high value? My issue that when I try to calibrate soil moisture values for a few layers to their daily observations, I would need multiple runs (at present I'm running 6 models with the same model parameters but with different print times, 246 for the first 4, 108 for the fifth, and 3 for the last model) for any given set of model parameters. It'd be great if I could just have a single run with any combination of model parameters.

Thank you!
Sincerely,
Ravindra

Jirka
Posts: 5216
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Now sure how to update a model parameter and the print time value

Post by Jirka » Wed Jan 06, 2021 9:23 pm

You can download an older version of the source code at the HYDRUS website and recompile it with new dimensions. J.

Hydraus_1d_RD
Posts: 16
Joined: Thu Dec 17, 2020 10:11 pm
Location: USA

Re: Now sure how to update a model parameter and the print time value

Post by Hydraus_1d_RD » Thu Jan 07, 2021 5:18 pm

Thank you!

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