July 21, 2022

3D visualization of voronoi gridded models with Model Viewer for Modflow 6 - Tutorial

July 21, 2022/ Saul Montoya

Model Viewer for Modflow 6 was launched in April 2022 and it is a version of Model Viewer customized to display the features, grid and results of MODFLOW 6 models. We have done an applied case for the visualization of a MODFLOW 6 DISV model that has a voronoi mesh. The tutorial covers the steps to visualize the model grid lines, grid shell, isosurfaces, color grid, flow directions among other visualization options.

June 09, 2022

Are hydrogeologists / numerical modelers forbidden from cloud services?

June 09, 2022/ Saul Montoya

In the semantic space the forbidden word is related to refuse to allow, and thus can create a controversy with the freedom of hydrogeologist / numerical modelers to choose whichever tool that can make the work done or the simulation run. However we as specialists in one part of the dynamics of the subsurface are conscious that solutions can not and must not be evaluated by single criteria.

December 01, 2021

Applied case of hydrogeological conceptual modeling on a hillslope area with QGIS

December 01, 2021/ Saul Montoya

In order to understand the relationship between groundwater flow and slope stability, a study area over a hotspot in the US. Landslide Inventory was selected. The geology, groundwater wells, elevation, and climate conditions were reviewed to develop a hydrogeological conceptual model that will be the basis for a numerical model of the groundwater flow regime. This webinar deals with the review of available spatial data related to the groundwater flow regime on a hillslope area at Mukilteo city, Washington, US. Information from geology, meteorology, observation data and boundary conditions will be discussed in a QGIS session with regards to the construction of a groundwater numerical model in MODFLOW.

November 08, 2021

Two open geological modeling softwares that you should know about

November 08, 2021/ Saul Montoya

For geologists, hydrogeologists, geostatistics, petroleum engineers, and other related professionals the choice for 3D geological modeling software was related to expensive and restrictive software that was in fact a “de facto” choice in several companies and institutions.

Although it is a choice of any company or professional to select the software anyone will use to model the geological units, a great gap subsides (using a geological term) on the use of this expensive software. If the software is expensive, how expensive will it be to get trained on this software? If few people have skills with certain software, how easy would it be to change to another software? How people can assess the quality of one software if they have no full capability on managing several softwares. As you have seen, restrictions on the licenses lead to these subsiding gaps, faults on quality, and an intrusion of professional ignorance.

October 25, 2021

How long does it take to develop a groundwater model for my research project / master thesis?

October 25, 2021/ Saul Montoya

Developing a hydrogeological research project that considers groundwater modeling for a bachelor thesis or a master thesis requires you to take into consideration several topics, such as input data, hydrogeological knowledge and time to learn the software in order to provide a numerical simulation that reaches the objectives of your research project.

Learning a software for groundwater modeling should be easy as developing some tutorials and playing around with your own data; however it is not that easy since it involves the review of lots of documentation, have strong knowledge in hydrogeology and numerical modeling and deal with uncertainties and numerical unconvergences.

October 04, 2021

New website! MODFLOW Questions and Answers: ask anything on groundwater modeling

October 04, 2021/ Saul Montoya

Until now we had limited options to provide specific support in groundwater modeling. We know that modeling requires the review of extensive documentation and practical work with the software and sometimes or most times we don't have the time to sort things out.

September 17, 2021

The Groundwater Project as a source of free books in basic and applied hydrogeology

September 17, 2021/ Saul Montoya

We usually received some emails and messages regarding basic or reference books and publications in Hydrogeology and we didn't have any reference of free and high quality material until we knew about the Groundwater Project. It´s true that we found the project website some months ago, but it was at the latest IAH conference where we had a presentation with a complete overview of the program.

August 23, 2021

What to do when your MODFLOW MT3D contaminant plume doesn’t migrate?

August 23, 2021/ Saul Montoya

This is a problem that every hydrogeologist - numerical modeler has faced many times over his/her professional career independently from the theoretical background and skills with the code, graphical user interface or Python library.

We don’t know why groundwater “flows” and a contaminant plume “migrates” when both move on the aquifer system. After you construct you model geometry, setup the flow boundary condition, specify your transport package, define your contaminant sources, run your MODFLOW flow model and then run your MT3D model (or even your MT3DMS model) you will find that there is no plume, none, nada, nichts.

August 18, 2021

Open source groundwater software besides MODFLOW - Updated July 2023

August 18, 2021/ Saul Montoya

A special concern arises from the gap between the stage of development of open source groundwater software and the actual capabilities of the common groundwater modelers (we mean, the main group of modelers). Even though we are passionate about software we don’t find the time or the right momentum to have a real experience with those codes.

From our research, we have listed the top open source groundwater software with a brief summary of the capabilities and useful links. We have to mention that there are some packages that can simulate groundwater flow in software like OpenFoam; however, those variants are not listed here.

June 24, 2021

How to install the Python geological modeling library Gempy in Windows with Debian and WSL

June 24, 2021/ Saul Montoya

Gempy is an open-source library for modeling geology written in Python. The library is capable of creating complex 3D geological models including structures, fault networks, and unconformities and it can be coupled with uncertainty analysis.

Due to the required packages and specific configuration the installation of Gempy is a challenge on Windows, we have developed an alternative installation process by the use of a Debian kernel under a Windows Subsystem for Linux. This tutorial shows the complete procedure to install Gempy from the Debian kernel setup to the review of the Gempy in Python.

April 15, 2021

Gypsum and Anhydrite solubility calculation with Phreeqc and Python - Tutorial

April 15, 2021/ Saul Montoya

Tutorial for the calculation of the solubility and thermodynamic stability of gypsum and anhydrite. The example simulates the dissolution of two minerals in a beaker at equilibrium, and the beaker is heated step-wise from 25ºC to 75ºC. Concentrations and saturation indices for the initial solution and the batch reaction are shown as Pandas dataframes and plotted as bar diagrams on a Jupyter Notebook. Finally a plot of the saturation index for anhydrite and gypsum with temperature is generated from an iteration over the batch reaction steps.

April 08, 2021

Advances in Modeling Groundwater Flow and Transport with MODFLOW

April 08, 2021/ Saul Montoya

In 2017, the U.S. Geological Survey released a new core version of the MODFLOW program. This new version, called MODFLOW 6 (the sixth core version), extends the core MODFLOW capabilities to include robust solutions for complex water table problems, support for generalized meshes with focused resolution within areas of interest, and support for multiple models and multiple types of models within the same simulation. In addition to the Groundwater Flow Model, MODFLOW 6 now contains a Groundwater Transport Model, which can run simultaneously with the flow model or as a separate simulation using the results from a previous groundwater flow simulation.

April 07, 2021

Seawater speciation modeling with Phreeqc coupled with Python and Pandas - Tutorial

April 07, 2021/ Saul Montoya

The speciation modeling allows to calculate the distribution of aqueous species in a solution. Phreeqc is capable to simulate this speciation calculation and we are going to demonstrate this capability on a study case of aqueous species in seawater.

We have done a tutorial for the speciation modeling of seawater with Phreeqc that runs under Python in a Jupyter Lab enviroment. The code can run the Phreeqc executable, define the databases and stablish the output files. Results from simulation are available as Pandas dataframes and plots are made for the main components and the distribution of saturation indices.

February 27, 2021

Should groundwater models from environmental evaluations be done in open source software?

February 27, 2021/ Saul Montoya

The topic of open source software and environmental assessments has some interesting associations. For example, if an investment project delivers a groundwater model in Xflow software, the environmental evaluator needs an Xflow license in order to open the model, review the simulations, and report on their observations. But what about civil society? or the communities that have an interest in knowing how the model is built or in the results of the predictive simulations, do these people also need an Xflow license? And what happens if another regulator wants to review the model, can they do so or they can only ask for a technical opinion?

December 14, 2020

Hatarilabs presents its study area for integrated and sustainable groundwater management

December 14, 2020/ Saul Montoya

Because field work and numerical models are just tools for the sustainable management of our groundwater resources we have searched a study place to develop a long-term project on a high-stressed aquifer that will lead to sustainable and effective groundwater policies. The study area is an alluvial aquifer that was primarily used for agriculture production with an neighboring unplanned urban development that has increased the domestic / industrial water demand. Several pumping schemas were implemented on the area and have affected the groundwater levels and the water availability for agriculture.

October 30, 2020

Review of the latest functionalities of the new release of MODFLOW 6 (mf6.2.0)

October 30, 2020/ Saul Montoya

Modflow6 is the latest version of the USGS code for groundwater modeling MODFLOW. This version has been coupled with another USGS open source software as Model Muse and Flopy and can implement diverse spatial discretization structures on a complete rearrangement of packages and keywords. We feel that there is a gap on the capabilities from a common groundwater modeler to adopt all the new development on Modflow and other open source groundwater software therefore we have prepared a video with the summary of this new release.

October 02, 2020

Basic tutorial of geological modeling with Python and Gempy

October 02, 2020/ Saul Montoya

We have created a tutorial of geological modeling based on geological contacts and surface orientations. The tutorial was developed in a Gempy container that runs under Docker in Windows 10; the tutorial covers the software installation and the geological modeling scripting.

September 30, 2020

A comprehensive list of specific Python packages for hydrogeology and groundwater modeling

September 30, 2020/ Saul Montoya

Development of open source software brings amazing new tools in all fields. In hydrogeology and groundwater modeling there is an increasing number of specific open source software and programming packages. We wanted to compile the latest libraries for Python related to hydrogeology, we asked for references and researched over the web to provide you the following list.

August 30, 2020

Modeling impermeable walls with MODFLOW 6 and HFB Package - Tutorial

August 30, 2020/ Saul Montoya

Modeling the performance and effectiveness of flow barriers or impermeable walls on the groundwater flow regime is a challenge due to the wall geometry / orientation and discretization requirements. The package Horizontal Flow Barrier was designed to simulate barriers of defined thickness and conductances that are located in between flow cells, in this way the flow barrier is independent for the model discretization. This package is not new, it dates back to 1993, and it was implemented on many MODFLOW versions.

August 24, 2020

Strategies for a hydrogeologist to develop advanced open source groundwater modeling software

August 24, 2020/ Saul Montoya

There are some shining moments in live where a normal hydrogeologist decide to develop open source software for groundwater modeling and for every great task everyone needs an strategy.

You might need a plan to develop your hydrogeological career but you will certainly need an strategy to develop groundwater modeling software. We have to see a strategy as the optimization of steps towards a goal, from great strategists as Hannibal Barca against the Roman empire, we need to see the whole picture and then decide the best steps to take with the resource available.

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