Water Content Dependence - Solute Reaction Parameters

A discussion forum for users of the new HYDRUS 2D/3D. HYDRUS is a software package for simulating water, heat and solute movement in two- and three-dimensional variably saturated media. Happy Posting!
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Ryan Threndyle
Posts: 5
Joined: Wed Nov 18, 2020 7:42 pm
Location: Canada

Water Content Dependence - Solute Reaction Parameters

Post by Ryan Threndyle » Wed Nov 18, 2020 8:47 pm

Hi there!

When setting the reference water content, does it matter if this value is positive or negative?
From what I can tell the walker equation can't be solved if the value is negative, is the absolute value taken here if a negative number is entered?

Best,
Ryan

Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Water Content Dependence - Solute Reaction Parameters

Post by Jirka » Wed Nov 18, 2020 11:32 pm

The reference water content has to be obviously positive (there is no such thing as negative water content). However, we calculate the reference water content from the reference pressure head (h_ref), which should be negative. We do not take the absolute value. We you give the positive value for the pressure head, the reference water content will be equal to the saturated water content. J.

Ryan Threndyle
Posts: 5
Joined: Wed Nov 18, 2020 7:42 pm
Location: Canada

Re: Water Content Dependence - Solute Reaction Parameters

Post by Ryan Threndyle » Thu Nov 19, 2020 5:55 pm

Ahhh that makes sense. Thank you!

Ryan Threndyle
Posts: 5
Joined: Wed Nov 18, 2020 7:42 pm
Location: Canada

Re: Water Content Dependence - Solute Reaction Parameters

Post by Ryan Threndyle » Fri Nov 20, 2020 2:58 pm

Two more follow on questions.

1. In the 'Water Content Dependent Solute Reaction Parameters' window, what is meant by the "prime" and "0" inputs ie. SinkWater1', SinkSolid0, etc. compared to the first three SinkWater/Solid/Gas 1

2. Does the water content have an impact on both SinkS1 and SinkL1, as well as first order attachment and detachment of the colloid (solute 1), or does it only alter one of these sets of parameters?

Best,
Ryan

Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Water Content Dependence - Solute Reaction Parameters

Post by Jirka » Mon Nov 23, 2020 5:48 pm

Ad 1. Obviously, there is the user manual or Context Sensitive Help.
Ad 2. There is a separate entry for SinkS1 and SinkL1, so yes. Water content dependence is implemented for standard solutes (it was implemented for pesticides), not particles (attachment/detachment). J.

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