Solute output files

[hpsalo]

I wonder if I am reading the solute.out files correctly. I would like to calculate pH of a bottom boundary. In our model setup we have six soil layers (initial pH 4.7–7) and horizontal drain bottom boundary at 1.2 m depth. I am trying to calculate the pH of drain discharge water from H+ concentration. Which of the columns in the solute1.out (Total_H) file tells me the H+ concentration? I was using the cBot-column to calculate the pH of the drain water but this gives me very low pH values (lower than is in the soil profile). Can this be correct? Based on the initial values, our hypothesis was that the drain pH should be close to 7 at the beginning of the simulation and go down as the simulation goes on. I also tried to calculate the H+ concentration using cvBot flux and drain discharge, but this gives me different result compared to pH calculated from cBot values.

Thank you in advance for the help!

- Heidi