Skip to main content Link Search Menu Expand Document (external link)

License: GPL v3

The framework G³M-f

The global gradient-based groundwater model framework (G³M-f) is an extensible program to build groundwater models. Its primary purpose is to be used as a central building block for the global groundwater model G³M. G³M is a global gradient-based groundwater model which adapts MODFLOW principles for the global scale. It is written in C++ and intended to be coupled to the global hydrology model WaterGAP ( While it is intended to be used as a memory coupled model, it can also run a standard standalone groundwater model.

It is mainly intended to be used by developers of global hydrological models (including land surface models and others) who want to simulate groundwater in a gradient-based manner. In principle, it can also implement any other, e.g., regional, groundwater model. Its main feature compared to MODFLOW is its extensibility, speed, and in-memory coupling capability.

For collaboration on coupling this model to other hydrological models, please contact Dr. Robert Reinecke (rreinecke on github).

Check out the project on GitHub


Global model description in GMD

Sensitivity Analysis in HESS

Data and code dois

Code publication in JOSS: DOI

Outputs of Reinecke et al 2019 in GMD: DOI


To compile the program, you will need:

clang >= 13 with openMP (currently gcc is not supported)
cmake >= 3.15.3
libboost >= 1.71

Built With


Please read for details on our code of conduct, and the process for submitting pull requests to us.


We use SemVer for versioning. For the versions available, see the tags on this repository.

Authors and Contributors

  • Robert Reinecke - Initial work Maintainer
  • Daniel Kretschmer - Variable density flow Maintainer
  • Sebastian Ackermann - WaterGAP coupling Maintainer

Past Contributors

  • Alexander Wachholz - Documentation review and NZ model Developer
  • Christoph Niemann - Spatial IDs Developer


This project is licensed under the GNU General Public License - see the LICENSE file for details. Please note that the code contains a modified version of the Eigen3 library which is published under the MPL 2.0.