adding solutes inside model domain

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ryanj
Posts: 3
Joined: Wed Mar 07, 2007 10:27 pm
Location: USA

adding solutes inside model domain

Post by ryanj » Wed Mar 07, 2007 10:53 pm

Greetings,

I am interested in predicting contaminant concentrations entering the water table for two solutes (solute one conservative; solute two nonconservative) under varying atmospheric conditions over ~ 200 hundred years. However, the source term I am trying to simulate is located inside my domain (similar but not equivalent to a buried drum).

I would like to incorporate a constant solute source-term concentration (for a handful of nodes) in the middle of my model domain but have not discovered how to implement this in HYDRUS-1D.

Any insight would be greatly appreciated.

--Ryan

Jirka
Posts: 4827
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Post by Jirka » Thu Mar 08, 2007 12:16 am

Ryan,

Declare the area where you want to have a solute source as a different material layer. Then specify all parameters the same except for the zero order production. This will lead to the release of solute at a constant rate at this location.

Jirka

ryanj
Posts: 3
Joined: Wed Mar 07, 2007 10:27 pm
Location: USA

Post by ryanj » Thu Mar 08, 2007 4:42 pm

Jirka, thank you for the suggestion. I have a quick follow-up question to ensure that I understand the issue conceptually.

Does adding the zero-order rate constant (for a dissolved phase) amount to the material layer releasing X mg/L per unit time step, and therefore an increased number of nodes in this layer does not amount to more mass being released rather finer spatial discretization?

--Ryan

Jirka
Posts: 4827
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Post by Jirka » Thu Mar 08, 2007 11:06 pm

Look at the governing equation. If you specify it for the liquid phase, then it will be gamma*theta*t*length the node represent, i.e., [M/L3/T]*[L3/L3]*[T]*[L]=[M/L2].

J.

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