Negative concenteration

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Posts: 7
Joined: Thu Sep 24, 2020 2:38 pm
Location: Iran

Negative concenteration

Post by mahdiye.latifi76 » Sun Nov 22, 2020 5:31 am

Hi, I callibrated HYDRUS for a drain and then run it for long-time, then concentration in some long-time cases became negative in some places, what is mean? can somebody please help me with this.
Thank you

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

Re: Negative concenteration

Post by Jirka » Sun Nov 22, 2020 9:45 pm

The negative concentrations are likely the results of the oscillatory behavior of the numerical solution. See Chapter “6.4.6. Oscillatory Behavior” of the Technical Manual on how to avoid numerical oscillations (e.g., use options such as upstream weighting, artificial dispersion, or the performance index). J.

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