Re: Baseflow Dominate periods (RE: SOlution Fractions

["David L Parkhurst" <dlpark@xxxxxxxx>]

> Opps.  I sent you the wrong file.  Pl. use this.
There's 3x times the Cl- in B.

I don't think you can dissolve that much halite. Looks to me like the
evaporation factor should be larger, about 8 L goes to 1 L. To model this
you need to remove the halite, but add balances on Na and Cl. I also doubt
that biotite dissolves or precipitates. If you remove halite and biotite,
you can probably ignore the potassium, but you'll need a sink for Mg. For
starters, I might guess that it is taken up with calcium into calcite. You
can model this by adding magnesite and just combine the calcite and
magnesite in your head as a magnesian calcite.

> Do you have any suggestions about how I can
control the water balance during baseflow
(&very low evap) months ?  I'm attaching an example.
There is much more measured flow at B (10x)than at A due
to contribution of lateral&baseflow.  Perhaps,
there are other sub-routines/keywords in phreeqc that
I could use ?

You need a composition for the ground water that is discharging to the
stream. Then you can mix the stream with the ground water to make the final
stream water. INVERSE_MODELING allows multiple initial solutions that mix
together simply by adding another solution number on the -solutions line.
The last solution number is the final water.

David





David Parkhurst (dlpark@xxxxxxxx)
U.S. Geological Survey
Box 25046, MS 413
Denver Federal Center
Denver, CO 80225

Project web page: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled