ex16 {phreeqc} | R Documentation

## Example 16–Inverse Modeling of Sierra Spring Waters

### Description

This example repeats the inverse modeling calculations of the chemical evolution of spring-water compositions in the Sierra Nevada that are described in a classic paper by Garrels and Mackenzie (1967). The same example is described in the manual for the inverse-modeling program NETPATH (Plummer and others, 1991 and 1994). The example uses two spring-water compositions, one from an ephemeral spring, which is less chemically evolved, and one from a perennial spring, which probably has had a longer residence time in the subsoil. The differences in composition between the ephemeral spring and the perennial spring are assumed to be caused by reactions between the water and the minerals and gases it contacts. The object of inverse modeling in this example is to find sets of minerals and gases that, when reacted in appropriate amounts, account for the differences in composition between the two solutions. The example can be run using the `phrRunString` routine.

### Source

http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc

### References

http://pubs.usgs.gov/tm/06/a43/pdf/tm6-A43.pdf

### See Also

Other Examples: `ex10`, `ex11`, `ex12`, `ex13a`, `ex14`, `ex15`, `ex17`, `ex18`, `ex19`, `ex1`, `ex20a`, `ex21`, `ex22`, `ex2`, `ex3`, `ex4`, `ex5`, `ex6`, `ex7`, `ex8`, `ex9`

### Examples

    phrLoadDatabaseString(phreeqc.dat)
    phrSetOutputStringsOn(TRUE)
    phrRunString(ex16)
    phrGetOutputStrings()

[Package phreeqc version 3.4.10 Index]