Data for the inverse solution

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T ze
Posts: 5
Joined: Wed Feb 27, 2019 11:28 am
Location: China

Data for the inverse solution

Post by T ze » Wed Feb 27, 2019 1:11 pm

Hello, i want to simulate groundwater recharge for the deep soil layers for a long time series about 22798 days. I just have the soil texture distribution and the atmosphere data and the measured soil water content of 18-m soil layers at the last day. I want to utilize this soil water content data and soil texture to inverse parameters n and ks in VG equation.
The question is that i set the data for inverse solution is that x:depth (-20,-40,-60....-1800),Y:soil water contet, type:13, position:5, weight:0.5 or 1. The print time is 5. So, i am not sure this is right or not, especially that the position should be the day 22789 or the serial number of print time 5. Detail information about the set is below.
Hope for you reply.
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source data.zip
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Jirka
Posts: 4716
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Data for the inverse solution

Post by Jirka » Thu Feb 28, 2019 1:44 pm

Your setup of the objective function (i.e., X, Y, Type, and Position) is correct as you can clearly see from the output model (i.e., that the model interprets the data correctly).
Theta_Profile.png
Theta_Profile.png (33.35 KiB) Viewed 302 times
However, I would be skeptical about the ability of the model to estimate soil hydraulic parameters of multiple soil layers from one-time water content profile.

J.

T ze
Posts: 5
Joined: Wed Feb 27, 2019 11:28 am
Location: China

Re: Data for the inverse solution

Post by T ze » Fri Mar 01, 2019 3:03 am

]Hello,
Thans for you reply. I have another question that why the fitted water content in the fit out file is different from the moisture data in Nod_inf file at the print time 5 ( day 23741). They are both the same day, both at the end of the day I simuated. So I am curious about which data is the fitted soil water content after i inversed. I think hydrus should give us a simulated water content with the inversed soil hydraulic parameter.
Hope for your reply.

Jirka
Posts: 4716
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Data for the inverse solution

Post by Jirka » Fri Mar 01, 2019 1:24 pm

I'm not sure what your problem is. Lines in the graph in my previous emails are read from the Nod_inf.out file obtained with the final calibrated/fitted parameter values. The values in Fit.out (in the Fitted columns) are exactly the same values as those in the Nod_inf.out. Thus your claim that they are not is wrong. J.

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