Coupling GoldSim and MODFLOW using a Python Interface

This post describes a method for coupling GoldSim with MODFLOW using GSPy (GoldSim's Python interface) and FloPy (a Python package for creating MODFLOW models). The approach builds on existing work like the Dynamic Coupling of GoldSim and MODFLOW/MT3D project but focuses on a simplified implementation suitable for educational purposes.

Implementation Approach

Traditional model coupling typically requires:

• Writing temporary input files
• Managing external executable calls
• Parsing output files for results
• Handling timing and synchronization
• Managing file system operations

The GSPy + FloPy approach uses:

1. GSPy to handle communication between GoldSim and Python
2. FloPy to create and manage MODFLOW models in memory
3. Python functions that receive GoldSim inputs and return results
4. FloPy's built-in file management for MODFLOW input/output

This implementation uses a Tutorial 2 style MODFLOW setup for educational purposes.

Dynamic Coupling of GoldSim and MODFLOW / MT3D

Posted by Jason Lillywhite

From time to time, we hear from GoldSim users asking about the possibility of linking MODFLOW with GoldSim dynamically. This is important because the combined model is useful for integrating accurate groundwater flow and transport models with decision support, hydrologic, and probabilistic models built in GoldSim. Folks at Barr Engineering were able to pull this off using a realistic hypothetical application and presented their application at the poster session of our 2015 User Conference.