Description of a post-processor for MODFLOW

Abstract

To facilitate data output and data presentation from MODFLOW model runs, the post processor “MOD-PP” has been written. This program reads MODFLOW’s binary and ASCII output files and writes the results into comma delimited files to be viewed in Excel. The program is able to: write (i) head data for user specified observation boreholes for all stress periods, (ii) water balances for all stress periods for all boundary conditions used in a model, (iii) river flow to and from the aquifer for all river cells over time, as well as for up to five specified river sections and for the entire river course and iv) stream leakage to and from the aquifer for all stream cells and for the entire stream course over time, as well as flows within stream cells and within the entire stream over time. The program, which is written in Visual Basic 6.0 can be applied to any steady-state or transient MODFLOW model and has no restrictions on layer, column or row numbers. This manual describing the post-processor is divided into 7 sections. After this introduction, section 2 gives an overview of how the program operates and which MODFLOW output files are required in the various modules of the program. Section 3 introduces the water balance module. The module for reading and writing groundwater head data for user-specified observation boreholes is described in section 4, while section 5 and 6 give information about running the river and stream modules