Advanced Groundwater Modeling Techniques with MODFLOW 6 and PEST++

This 2-day workshop will demonstrate some of the latest functionality available in MODFLOW 6 and PEST++, with an emphasis on scripting with FloPy and pyEMU. There will be (optional) hands-on exercises, as well as the opportunity to participate in numerous discussions

Aspirational Schedule:
Day 1: MODFLOW-6 and FloPy

• Introductions and Overview
• Checking your installation
• Overview of MODFLOW 6
• A brief introduction to FloPy
• Structured and unstructured grids (DIS, DISV, DISU) and LGR
• Transport
• Particle tracking - PRT
• Solute transport - GWT
• Energy transport - GWE
• ○ Variable density groundwater flow and transport
• Extended MODFLOW 6 - parallel, netcdf/ugrid
• MODFLOW API demonstration
• Mf6ADJ demonstration

Instructors:

Advanced Groundwater Modeling Techniques with MODFLOW 6 and PEST++

This 2-day workshop will demonstrate some of the latest functionality available in MODFLOW 6 and PEST++, with an emphasis on scripting with FloPy and pyEMU. There will be (optional) hands-on exercises, as well as the opportunity to participate in numerous discussions

Aspirational Schedule:
Day 2: PEST++ and pyEMU

• Introductions and Overview
• Why modeling is hard
• Checking your installation
• Uncertainty, Bayes, and learning from data
• Predictive modeling
• GMDSI notebooks - they rock!
• Intro to the model we are using today
• The PEST model interface and model run parallelization
• Hands on: running PstFrom with pilot points
• On your own: GMDSI geostats and pilot points
• Ensemble methods, including:
• Theory
• Case study: Ruataniwha
• On your own: GMDSI notebooks
• Hands on: running an iterative Ensemble Smoother (pestpp-ies)
• Management Optimization
• Reframing from UA to OPT
• Linear programming
• MOEAs and pareto concepts
• Case study: Harney
• On your own: GMDSI notebooks
• Hands on: running a mgmt optimization tool
• Emulation
• Response matrices
• Gaussian Process Regression (GPR)
• Data-space Inversion (DSI)
• DSIVC
• pyPestWorker
• On your own: GMDSI notebooks (and what’s coming)
• Hands on: running DSI
• Optional: Why is this so hard?!

Instructors:

Modelling reliable groundwater recharge with MIKE SHE

A quite common task is to produce groundwater recharge rates as inputs for other common groundwater models, like FEFLOW or MODFLOW, which are not capable of simulating groundwater recharge themselves, like MIKE SHE can do. The most common approach is to use empirical equations or simplified conceptual approaches to provide a rough guess for the required groundwater recharge, but they tend to neglect important processes like capillary rise, heterogeneous soil distributions or effects of lateral overland flow.
Especially for this purpose, it is possible to deactivate the full 3D groundwater module in MIKE SHE and use MIKE SHE only as surface water and soil hydrology model in a limited version.
In this half-day course from 9 am to 12 am you will learn how to build up a complete MIKE SHE model for Climate, Landuse, Overland Flow and the Unsaturated Zone from scratch.
After this course you will be enabled to simulate hydrological processes affecting groundwater recharge using a fully distributed approach. Apply precipitation and evapotranspiration as constant values, station data, or transient grids. Choose lumped or discretised methods for Overland Flow and Unsaturated Zone simulations, and assess land use impacts on recharge rates. Optional snowmelt and irrigation features account for seasonal and agricultural effects.

Additional benefits and recommendations:

• Generate accurate groundwater recharge rates for models such as FEFLOW or MODFLOW, or assess recharge directly as a key freshwater resource within your catchment.
• When combined with the River Hydraulics add-on, the Linear Reservoir method converts simulated recharge into lateral inflows for your coupled MIKE+ Rivers model, enabling direct calculation of river discharge and water levels as key inputs for groundwater modelling.
• This basic MIKE SHE version excludes the fully distributed 3D Finite-Difference groundwater model for the Saturated Zone and therefore does not simulate groundwater levels or flows. Instead, the groundwater table must be defined as an input for the Unsaturated Zone model. This simplification is suitable for regions with groundwater depths greater than two to three metres, where capillary rise effects are minimal.
• For use in the MODFLOW RCH package, DHI has developed a methodology in MIKE OPERATIONS, based on Zonal Statistics, to preserve mass when transforming DFS2 gridded recharge rates to MODFLOW grid files. Contact mike@dhigroup.com to request a standalone executable tool, that automatically does the transformation for you.
• Recharge rates generated as DFS2 grids can be imported directly into FEFLOW using its built-in import function (see KA-01204 on the DHI Customer Care Portal for details).

Instructor:

Introduction to Groundwater Modelling Using FEFLOW

FEFLOW is widely recognised as a comprehensive software package for simulating subsurface flow and transport processes. Its unique meshing capabilities—supporting both structured and unstructured meshes— provide a high degree of flexibility, allowing users to represent geological settings ranging from simple to highly complex geometrical configurations in detail. FEFLOW is used globally by leading research institutes, universities, consulting firms, and government organisations.
This course provides a comprehensive overview of the software workflows involved in developing groundwater flow and contaminant transport models using FEFLOW. Through a balanced combination of theoretical background and hands-on practical exercises, participants will acquire the knowledge and skills required to begin modelling independently with the software.
Participants with prior experience using earlier versions of FEFLOW will also receive a structured introduction to the latest workflows and enhanced functionalities. In addition, the course offers opportunities for professional exchange and discussion with an experienced DHI trainer and recognised modelling expert.

Course Topics:

• Overview of FEFLOW application areas
• Introduction to FEFLOW and the graphical user interface
• Creation of 2D and 3D mesh geometries
• Development of flow models for confined and unconfined groundwater conditions v
• Stationary and transient groundwater models
• Integration and use of external datasets for building FEFLOW models
• Evaluation of model results (e.g., water balances, etc.)
• Visualization and animation of simulation results
• Open discussion
• Introduction mass transport (Optional)

This course is designed for professionals working in groundwater hydrology, hydrogeology, and geology, including those employed by government agencies, state authorities, water management organisations, engineering firms, universities, research centers and consulting companies. It is suitable for both beginners in numerical groundwater modelling and experienced users seeking to refresh or deepen their existing knowledge.
Participants are expected to have a basic understanding of hydrogeology and groundwater flow processes. Prior experience with numerical modelling is advantageous but not required. The course is structured to ensure that both participants with no prior experience using FEFLOW and users of earlier software versions will benefit from the material presented.
Explore the full range of FEFLOW’s advanced simulation capabilities on our website.

Instructor:

General introduction to COMSOL - Subsurface and groundwater flow simulation

COMSOL Multiphysics is a finite element–based simulation environment widely used in the oil and gas industry for modeling coupled physical processes such as fluid flow, heat transfer, geomechanics, and chemical transport. Its multiphysics architecture allows engineers to integrate subsurface reservoir behavior with thermal and mechanical effects, which is essential for analyzing complex systems like enhanced oil recovery (EOR), wellbore stability, and reservoir compaction.
In groundwater applications, COMSOL is particularly valuable for simulating flow and contaminant transport in porous media. It enables high-resolution modeling of hydraulic gradients, reactive transport, and density-driven flow, which are critical for understanding aquifer behavior, pollutant migration, and remediation strategies. The platform’s flexibility allows users to define custom constitutive relationships and boundary conditions, making it suitable for site-specific hydrogeological studies.
For geothermal systems, COMSOL supports detailed modeling of heat extraction processes, including conduction, convection, and fluid circulation in fractured or porous reservoirs. It is commonly used to simulate geothermal doublets, borehole heat exchangers, and reservoir sustainability under long-term production scenarios. The ability to couple thermal, hydraulic, and mechanical (THM) processes provides a significant advantage in assessing reservoir performance and induced seismicity risks.

COMSOL offers several distinct benefits:

True multiphysics coupling: COMSOL is not specialized in groundwater flow and transport, it allows seamless coupling with additional physics (e.g., structural mechanics, electromagnetics), which is crucial for integrated reservoir studies.

Customization and flexibility: COMSOL provides a more open environment where users can implement custom equations and user-defined physics interfaces, whereas other tools can be domain-specific with predefined modules.

Advanced meshing and solver control: COMSOL offers greater control over numerical methods, adaptive meshing, and solver configurations, which can improve accuracy in highly nonlinear or coupled problems.

User interface and visualization: COMSOL’s GUI is highly interactive, with strong post-processing capabilities for multiphysics visualization.

COMSOL’s strength lies in its versatility and ability to handle complex, coupled systems that extend beyond traditional hydrogeology.

• Brief introduction to multiphysics modeling, setting up and solving a model using the Model Builder
• Turning a model into a simulation application that anyone can run
• Demonstration of the functionality for modeling single-phase and multiphase flow in porous materials. It also provides details on how to account for heat and mass transfer in the subsurface and to analyze its poroelastic behavior.

• Analyzing tunnels, excavations, slope stability, and retaining structures requires nonlinear material models specialized for geotechnical applications. This course will showcase the built-in material models for modeling deformation, plasticity, creep, and failure in soil, concrete, and rock.

• Uncertainty Quantification is used for understanding the impact of model uncertainty — how the quantities of interest depend on variations in the inputs of a model. It provides a general interface for screening, sensitivity analysis, uncertainty propagation, and reliability analysis. It helps to understand the key input to the quantities of interest, explore the probability distribution of the quantities of interest, and discover the reliability of a design. During this course various input parameters will be used to investigate the sensitivity of heat exchangers based on the input parameters.

Instructors: