A New Groundwater Energy Transport Model for the MODFLOW Hydrologic Simulator

Area of Science:

• Hydrogeology
• Environmental Science
• Geothermal Energy

Background:

• Subsurface heat transport is crucial for understanding climate change effects on ecosystems, geothermal energy potential, and groundwater quality.
• Previous MODFLOW simulations used solute-transport models for heat transport, which had limitations in handling complex conditions like unsaturated flow.

Purpose of the Study:

• To introduce and evaluate the new groundwater energy-transport (GWE) model type within MODFLOW 6 for accurate subsurface heat transport simulation.
• To provide a more robust and integrated approach for modeling heat transport in various hydrogeological settings.

Main Methods:

• The study utilizes the newly implemented Groundwater Energy-Transport (GWE) model type in MODFLOW 6.
• Simulations were performed on structured and unstructured grids, incorporating advanced packages for streams, lakes, wells, and unsaturated zones.
• The GWE model was accessed via the FloPy Python package and MODFLOW 6 API.

Main Results:

• The GWE model in MODFLOW 6 successfully simulates heat conduction through both water and aquifer materials.
• The model accounts for thermal bleeding from saturated overburden into groundwater flow fields.
• It overcomes previous limitations by handling transient, unsaturated flow conditions more effectively.

Conclusions:

• The GWE model in MODFLOW 6 represents a significant advancement for simulating subsurface heat transport.
• This new capability enhances the study of climate change impacts, geothermal energy applications, and groundwater quality.
• The integration with FloPy and the MODFLOW 6 API ensures accessibility and broad applicability.