W-Volume and hCritA

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RobinD
Posts: 2
Joined: Wed Apr 17, 2019 12:16 pm
Location: France

W-Volume and hCritA

Post by RobinD » Thu Apr 18, 2019 8:06 am

Hello,
I allow myself to post a message on this forum because after many searches I did not find answers to my problem.

I need to model the water content of a soil knowing the precipitation and daily FTE over a period of 3 years.
I started the simulation, and that's where my questions start.

Is the "W-Volume[L]" value given by the software in "balance.out" the height of water present in the soil, taking into account the porosity and bulk of soil compounds (rocks, aggregates, etc.) (on the left of the image) or is it the quantity of water extracted from the soil (on the right of the image)?

Image

Also, I don't really understand how to simulate an experiment at constant atmospheric pressure, what kind of values should I enter in the "hCritA" column (if that is the column that be used for that...) ?

Thank you very much for your help.

Robin.

Jirka
Posts: 4762
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: W-Volume and hCritA

Post by Jirka » Thu Apr 18, 2019 3:33 pm

W-Volume is defined in the Manual as "Volume of water in the entire flow domain or in a specified subregion [L]" and how it is calculated is give by eq. 7.17.. That would be the figure on the right.

hCritA specifies the minimum allowed surface pressure head (defined from equilibrium conditions between soil water and atmospheric vapor). There is an extensive text on hCritA in the help.

J.

RobinD
Posts: 2
Joined: Wed Apr 17, 2019 12:16 pm
Location: France

Re: W-Volume and hCritA

Post by RobinD » Fri Apr 19, 2019 2:12 pm

Thank you very much for your answer

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