GFLOW an analytic element groundwater solver written by Henk M. Haitjema. GFLOW solves steady state groundwater flow in a single aquifer, with support for conjunctive groundwater/surface water solutions, and interface seawater intrusion solutions. GFLOW supports three-dimensional particle tracking, but employs the Dupuit-Forchheimer approximation, thereby ignoring resistance to vertical flow. The computational solver in the GFLOW groundwater modeling system is represented in the file GFLOW1.exe. EPA is the current host of the GFLOW modeling system https://www.epa.gov/hydrowq/gflow-groundwater-flow-analytic-element-model
The initial commit of this repository consists of the Fortran code associated with the public release version gflow1.exe (1/24/2018), which is the computational core of GFLOW. The gflow1 code was originally only compiled with the Lahey Fortran compiler on Windows. This compiler is discontinued as Lahey Computer Systems has been permanently closed since December 31, 2022
The is progressing on migrating to gfortran and supports multiple platforms. It can now be compiled not just on Windows, but also on macOS and Linux. Test Executables are available for Windows, macOS, and Linux under the releases section: https://github.com/USEPA/gflow1/releases
This repository serves three main goals:
- To demonstrate the integrity of the recompiled gflow1.exe on Windows, macOS, and Linux.
- To publicly host the original and refreshed gflow1 code for archival purposes.
- To provide a foundation for the development of new GFLOW user interfaces.
We have the following (tentative) plans, primarily focused on improving robustness and usability:
- Support for mixed case paths: gflow1 is not case sensitive when dealing with file paths and will internally transform file paths to upper case, since it was a Windows only application. While Windows is not case sensitive for file paths, macOS and Linux are. Ideally, the casing of paths can be preserved.
- Support for long paths: gflow1 currently supports paths of no longer than 256 characters.
- Fix compiler warnings: compilation with gflow1 currently emits many warnings. Ideally, we address all of these.
- Multi-compiler support: we currently only compile with gfortran. We intend to add Intel Fortran as well (and address new warnings as they pop up).
- The
'-freal-4-real-8'flag is required to force all reals to double precision, since the executable otherwise crashes when run. Ideally, all type declarations are updated to explicit double precision. - Add a basic set of integration tests.
A rudimentary QGIS plugin is available at https://github.com/huite/gflow-plugin.
While it doesn't support all features of the GFLOW GUI, QGIS offers powerful complementary capabilities including:
- Comprehensive geospatial data interaction
- Advanced visualization and data presentation
- Flexible vector geometry editing
- Access to various basemaps