Water Resources of the United States
A Data Input Program (MFI) for the U.S. Geological Survey Modular Finite-Difference Ground-Water Flow Model
U.S. Geological Survey Water-Resources Investigations Report 94-468
Today's computers can easily handle large modeling problems for which data preparation is a burdensome task. Considerable benefit can be obtained from an interactive program that helps prepare model input data. Such a program can prompt for the required data, check for errors, and ensure that files are created with the proper structure. Although it would be possible to add interactive data entry into the model program, this is not desirable because it would unnecessarily increase the required memory and increase the complexity of the program. Further, the wide variation in user preferences and needs makes it unlikely that any single method of interactive data input will meet all needs. It is better to have data entry separate from the model so that different data entry programs can be developed independently of the model program.
This report describes a data input program, called MFI, for the U.S. Geological Survey (USGS) modular three-dimensional finite-difference ground-water flow model (McDonald and Harbaugh, 1988), which is commonly called MODFLOW. MFI can also prepare data for MODPATH, which is a particle tracking program that uses flows calculated by MODFLOW (Pollock, 1994). Much of the data used by MODPATH is the same as that used by MODFLOW, so considerable redundancy is avoided by having one program prepare data for both.