GFLOW
Analytic Element Method for FLow		 Order No: TPS 25

Standard version: $500
Professional version: $975

GFLOW is an integrated groundwater flow modeling system based on the analytic element method. It contains a sophisticated Geographic Analytic Element Preprocessor (GAEP), a single aquifer analytic element model GFLOW1, a graphics post processor GFPRINT, and a digitizing program TABLET. Data preparation with GAEP is preformed in two steps:

  1. digitizing hydrography and background map features store in .dm files and
  2. on screen construction of the GFLOW1 input data file (the model).
The first step (digitizing) may be skipped by purchasing optional .dm file for the model area. These .dm files contain high resolution hydrography data, including surface water elevations that are automatically transferred to the model boundaries (streams, lakes, etc.) when creating GFLOW1 input data files. The availability of these ready to use digital map files is a unique feature of GFLOW, which lead to drastic cost savings in consulting applications. GAEP has a DXF file import option and generates detailed background map files for GFLOW1.

GFLOW1 is a conjunctive surface water and groundwater flow model based on the Dupuit-Forcheimer assumption, but it does support three-dimensional streamline tracing. The program includes features for simulation of line sinks and sources, injection and withdrawal wells, ponds, regional uniform flow, and areal recharge. The sources and sinks can be specified by recharge/discharge rates or by heads. Locally, transient flow due to a well or fully three-dimensional features may be included (e.g. partially penetrating well, shallow pond). Furthermore, the model can handle local heterogeneity and anisotropy. The program is highly interactive, allowing on screen data changes (mouse cursor on graphics screen), on screen data retrieval, and instant report ready graphics output from every graphics screen. When solving stream flow and groundwater flow conjunctively, all data pertaining to a stream reach can be written to a spreadsheet file. Stream flow or base flow is graphically represented by plotting the stream layout with a line width proportional to the flow.

The graphics post-processor GFPRINT may be run from inside GFLOW1 or as a stand alone program. It allows for scaling, rotating, and previewing of the graphics images. Graphics can be produced in black and white or color on more than 100 printers, or written to PostScript, PCX, and DXF files. GFPRINT has also a special facility for slide creation.

GFLOW is extensively tested and well documented proprietary program running under MS-DOS. In addition to its on-line context sensitive help facility, the GFLOW package comes with a 400 page user/reference manual, tutorial and validation document. The distribution diskette contains more than 15 example input data files (with their own tutorial instructions) plus all of the validation input files described in the validation document.

SYSTEM REQUIREMENTS

Intel 80486 or 80386 processor with math coprocessor, 4 Mb RAM, DOS 5.0 or higher, hard disk with at least 2 Mb free disk space, VGA graphics; the program will run as a DOS application under WINDOWS.

Developer: H.M. Haitjema (Haitjema Software, Inc.)