GMS:Importing an MT3DMS Simulation

It is often necessary to import an MT3DMS simulation that was not generated by GMS. Since GMS uses the standard MT3DMS file format, this is not a problem in most cases. However, there are a few steps and precautions that should be taken.

File Formats

GMS uses the standard MT3DMS file formats described in the MT3DMS documentation (Zheng, 1998). The files being imported must match these formats exactly. If the files were generated for a version of MT3DMS that uses a different set of file formats, the files will need to be edited before they can be successfully imported to GMS.

CON File

The source code of MT3DMS was changed to create a *.con concentration file instead of the default *.ucn file. GMS can read either the *.con or *.ucn file. The *.con file is written in the GMS binary dataset format. Both can be imported without an MT3DMS super file by changing the file extension to *.hed in the properties and then creating a text file with the same name in the same folder and changing that file's extension to *.mfn. GMS can then pull in this *.mfn file using the Read Solution command in the MODFLOW menu which will pull in the concentration values as if it were an output head MODFLOW dataset (e.g. example1.con -> example1.hed, then create text file example1.mfn to pull in).

Importing Super Files

GMS uses an MT3DMS super file to organize the files used by an MT3DMS simulation. This file is not a standard MT3DMS file. One approach to importing an externally defined simulation is to create an MT3DMS super file containing the names of the files used in the simulation using a text editor.