MODFLOW-USG Resources

MODFLOW-USG Resources

The newly released MODFLOW-USG (UnStructured Grid version of MODFLOW) provides a significant advancement in groundwater modeling. Along with a new set of capabilities, there are several changes to the underlying MODFLOW concepts. Thus there is a need to better understand the differences and similarities between the UnStructured version of MODFLOW and traditional Structured versions of MODFLOW (including MODFLOW-2000, -2005, -NWT, -LGR). This page contains links to several resources, white papers, and multi-media demonstrations of the capabilities of MODFLOW-USG and Visual MODFLOW Flex.

Support for PEST v.12.3

Support for model calibration with PEST v.12.3

Visual MODFLOW Flex 2012.2 introduces a new interface for PEST that has been designed for groundwater modelers of all skill levels. The intuitive, easy-to-use interface offers step-by-step guidance through the entire model calibration process, making it ideal for junior modelers and beginners with minimal PEST experience. At the same time, it offers support for advanced PEST features and direct access to the PEST control files from within the application, allowing experienced modelers to fully customize the PEST run.

  • Simple, intuitive user interface: A unique workflow-based GUI guides you through the PEST process from start to finish, allowing you to define PEST inputs more efficiently than other PEST interfaces, and lets you focus more on interpreting the inputs and results.
  • Manage and compare multiple models within a single project: Within a single project, easily compare the results of multiple PEST runs with the results of the original model. Visually inspect the differences between the original and PEST-adjusted property parameters side-by-side, and calculate differences in heads between several model runs to assess uncertainty and the impact to model calibration.
  • Support for Pilot Points: Including designation of fixed pilot points to ensure that PEST honors your field measurements and generates realistic and representative parameter values for your site conditions. Pilot points can be easily imported from existing GIS datasets or digitized manually in an interactive 2D viewer. Choose from a variety of symbol styles to distinguish between fixed and soft points in 2D/3D viewers.
  • PEST controls at your fingertips: The PEST dashboard allows you to quickly terminate PEST runs that are taking too long or not progressing.
  • One-click export to Excel™: Export formatted PEST results to Excel for creating fully-customized charts showing parameter values and sensitivities.
  • Instant access to PEST results: With Visual MODFLOW Flex, you no longer have to browse through folder directories and search for files containing the results from PEST. All PEST results are conveniently displayed directly within the application, giving you immediate access to information about the PEST run, and allowing you to make prompt, effective decisions.
  • Support for Standard PEST Functions: The PEST Check option automatically verifies that input files are free of formatting errors before starting a PEST run. Choose from several regularization options including Tikhonov (Preferred Value and Preferred Homogenous) and SVD Assist for faster run times, improved numerical stability and better, more reliable PEST results.
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Visual MODFLOW Flex 2013.1

What's New in Visual MODFLOW Flex 2013.1

Visual MODFLOW Flex 2013.1 delivers high-performance transport engines with exceptional 2D/3D visualization capabilities for accurate, reliable and efficient simulations of groundwater flow and contaminant transport.

  • Contaminant Transport Modeling: Effortlessly design and run MT3DMS contaminant transport simulations, and visualize rich 2D/3D renderings of concentration plumes
  • Improved Performance for Maximum Efficiency: Achieve accurate transport simulation results twice as fast with full 64-bit engine support
  • Increased capacity for larger models: Build large transport models with high-resolution MODFLOW grids (one million cells) with full 64-bit engine support
  • Enhanced 2D Visualization: Smoothly navigate and explore results and detailed model renderings with an enhanced 2D graphics engine
  • Multi-model Uncertainty Analysis: Easily compare the model results of multiple grid types, modeling scenarios and remediation strategies side-by-side within a single project, and choose the most reasonable model
  • Reliable QA/QC: Visually correlate plume locations to observed borehole, monitoring locations and your geological model to validate model assumptions and gain confidence in your results
  • Classic Numerical Modeling Workflows: Build your models from the grid up using traditional techniques that begin with 3D grid design (as in Visual MODFLOW Classic)

Cut Simulation Runtimes in Half

With 64-bit engine support, Visual MODFLOW Flex can dramatically reduce runtimes for MT3DMS transport simulations. To quantify the improvements in runtimes, a transport model with 670,000 cells and 15 stress periods was simulated in both Visual MODFLOW Classic and Visual MODFLOW Flex (32-bit and 64-bit). The resulting runtimes are shown in the graph below. The Visual MODFLOW Flex 32-bit and 64-bit simulations finished in 2700 seconds and 2400 seconds, respectively. The Visual MODFLOW Classic simulation finished in 5063 seconds, twice as long as the Visual MODFLOW Flex 64-bit simulation.

MT3DMS futási idők (Classic vs. Flex)

Bug Fixes and Enhancements

View the Visual MODFLOW Flex Readme for a full list of bug fixes, improvements and other enhancements.

3D plume migration
Large transport models
2D graphics engine
Evaluating grid discretizations

Visual MODFLOW Flex 2014.1

What's New in Visual MODFLOW Flex v.2014.1

Visual MODFLOW Flex 2014.1 delivers support for MODFLOW-USG - a new finite volume version of the USGS MODFLOW groundwater modeling program, that uses flexible and efficient unstructured grid geometries.

Benefits of Unstructured Grids

Increased Simulation Accuracy

Unstructured grids permit local grid refinement along model features such as wells and boundary conditions, in addition to supporting fully discontinuous layers, both of which deliver high resolution detail and accuracy around areas that matter the most.

Reduced Simulation Runtimes

Traditional MODFLOW grid refinement often results in an excessive number of grid cells outside the areas of interest which leads to an inefficient numerical model with unnecessary long run times. With unstructured grids, the grid refinement is focused only to the areas of interest, resulting in much fewer grid cells, more stable grid structures, and therefore reduced run times.

Superior Modeling of Complex Geology

Unstructured grids are flexible and conform easily to the natural variability found in surface features and subsurface stratigraphy. Unstructured grid layers permit discontinuous layers that pinch-out to zero thickness, providing a more realistic representation of complex hydrogeological conditions, and improved model stability.

Increased Numerical Stability

Unstructured grids in Visual MODFLOW Flex 2014.1 are composed of a special type of polygon called Voronoi Cells. Voronoi Cells are superior to other unstructured grid geometries (nested grids, quad-tree grids) as they completely honor the Control Volume Finite Difference (CVFD) constraints, and therefore do not require the Ghost Node Correction (GNC) package. In addition, well and boundary condition nodes coincide exactly with the grid nodes. This results in an efficient, robust and dependable numerical grid, with improved convergence and accuracy.

Why use Visual MODFLOW Flex for MODFLOW-USG simulations?

IntuitĂ­ve, Easy-to-use Interface

Visual MODFLOW Flex 2014.1 provides an easy-to-use interface for defining model inputs, running the model and visualizing impressive detailed 2D/3D renderings of model results.

A Multi-Model Environment

The conceptual modeling approach in Visual MODFLOW Flex allows you to easily generate an unlimited amount of numerical models from a single 3D conceptual model - all within a single project. Results from multiple numerical models can be compared and analyzed side-by-side within the same environment. This allows you to compare various MODFLOW-USG models with various levels of refinement, and validate against MODFLOW-2005 models.

The Conceptual Modeling Approach

The conceptual modeling approach makes it easy to build a 3D MODFLOW-USG numerical model. GIS-based representations of your boundary conditions (points, polygons, polylines) are automatically included in the grid generator, providing for a natural and intuitive workflow. Discontinous formations defined in the conceptual model are automatically converted to zero thickness layers in the unstructured grid. Numerical model inputs such as properties, wells, and boundaries are automatically populated from conceptual data.

Robust Grid Generator

Visual MODFLOW Flex has a built-in grid generator for unstructured grids that provides reasonable default settings for voronoi cells, and control over refinement levels around the model boundary, lines, and wells. Grids are efficiently refined around features, while maintaining the CVFD criteria, for superior performance and accuracy.

Powerful 2D/3D Visualization

Visual MODFLOW Flex's powerful 2D and 3D viewers are capable of displaying high-resolution renderings of your model inputs and results. Using interactive viewer controls you can visually inspect and analyze your results from any virtually angle to gain the critical insight needed to deliver effective decisions.

Localized grid refinement
Discontinuous geology
Voronoi cels

Visual MODFLOW Flex 2014.2

What's New in Visual MODFLOW Flex 2014.2

Define ZoneBudget Zones With Ease

Easily define zones for subregional water budget calculations by drawing polygon, polylines or points in the desired areas on your numerical model, or by choosing an existing data object, such as a shapefile or DXF layer.

New zones can now be automatically copied to multiple layers and edited directly via CSV file.

Support for Horizontal Flow (Wall) Barriers

The new release introduces support for the Horizontal Flow Barrier (HFB) Package which can be used to simulate barriers to flow such as slurry walls or faults. Wall boundaries are easily assigned using polyline shapes (digitized or existing conceptual model object) to represent the X-Y spatial extents, and horizon objects to represent the vertical extents.

Wall boundaries can be added to multiple layers within your model, and numerical attributes can be edited directly via CSV file. The Wall boundaries on the numerical model can be displayed in 3D view, and 2D views (layer and XS by row or column).

Improved Particle Tracking

Defining particles for MODPATH simulations has never been easier. In the new release, particles can be assigned by digitizing a circle, or drawing single particles. Particles can be quickly assigned to specific model layers to accommodate multi-layer pumping wells screens.

Particles can be removed from one or more layers. Simply draw a box around the desired area of your numerical model to remove any unwanted particles.

Water Table Visualization

Visual MODFLOW Flex 2014.2 is capable of producing detailed renderings of the water table. In 2D and 3D Viewers, the water table is rendered as a surface with color shading and contours. In cross-section view (row and column), the water table can be viewed as either smooth interpolated line, or as a "discrete" line where MODFLOW cell elevations are honored.

Water table data can be conveniently exported to CSV file for use in post-processing with other software.

Flexible Color Rendering Options

Customize the colors and value ranges, and display model properties, boundaries, heads, drawdown, concentrations and the water table exactly how you want them in 2D and 3D Viewers.

Advanced Editing of Numerical Model Inputs

Visual MODFLOW Flex 2014.2 gives you complete "back door" access to input files for advanced editing of numerical model data. Input data can be exported to CSV format, edited in Excel or your text editor of choice, and then loaded back into Visual MODFLOW Flex for visualization and processing. If you have existing scripts, these can be hooked up to the CSV file formats for efficient bulk edits of input files.

Export Charts to CSV Format

Model results can now be exported to CSV file format for loading into Excel or your preferred charting software for advanced charting and analysis (Observation vs Calculated Heads, Breakthrough Curves).

Other Improvements and Enhancements

  • Added support for rotated grids in the numerical modeling workflow
  • The default colors of property zones are now similar to Visual MODFLOW Classic making it easier to compare properties and boundary conditions between the Visual MODFLOW Flex and Classic interfaces
  • Improved navigation of workflows making it easier to skip completed steps.
Define Zone Budget zones with GIS data
Wall Boundary Condition
Improved methods for defining particles
Water table visualization in multi-view display
Customized Color Rendering of Concentrations
Export to Excel
Rotated numerical grids

Visual MODFLOW Flex 2015.1

What's New in Visual MODFLOW Flex 2015.1

Support for MODFLOW-NWT

MODFLOW-NWT is an enhanced version of MODFLOW that improves solutions for unconfined groundwater-flow problems where rewetting of dry cells typically occur. This version of MODFLOW is ideal for mine dewatering simulations, or any other scenarios where cells can dry out.

Precise Cell Assignment and Editing

Easily assign hydraulic properties and inactive cells to the numerical grid by drawing polylines or polygons, or selecting individual grid cells. Boundary conditions can be easily copied to other layers within your numerical model.

Easier Definition of Pumping Wells

Visual MODFLOW Flex 2015.1 provides a more natural approach to defining pumping wells by allowing you to define wells and screens on a per-well level. For wells that are screened across multiple layers, Visual MODFLOW Flex automatically calculates the proportion of the total pumping rate assigned to each well grid cell in the model.

Improved Pumping Well Visualization

Visualize well screen intervals in cross-sectional views and render pumping well locations by pumping well attributes such as pumping rate or concentration values.

Flexible Handling of Time Series Data

Conveniently import, view or edit pumping schedule data in relative times (e.g. time starting at 0 days), in addition to absolute time (e.g., 04/22/2015).

Advanced Particle Tracking Options

Define pathline travel time and time marker frequency for MODPATH particle tracking simulations.

Cell-by-cell Visualization

Display the calculated total flux into and out of grid cells, including baseflow, to easily identify gaining/losing surface water bodies such as rivers.

Bug Fixes and Enhancements

Assign properties
Well Screen Visualization
Pumping Well Rendering
Pathlines with travel time

Visual MODFLOW Flex 4.0

What's new in Visual MODFLOW Flex 4.0?

Visual MODFLOW 4.0 enables you to do more, in less time, and with greater flexibility. This new version re-introduces some key features from Classic (indicated below with a  CL  flag), plus exciting new features you've never seen before (indicated below with a  NEW  flag).

The development team heard from users around the globe that editing capacity was lacking, so this was improved and added many new user-friendly features, including but not limited to those listed below.

Grid Editing Enhancements

 CL  Numerical grid editing - you can now easily edit your numerical grids once they have been created by adding rows, columns, or layers, with full control over where and how many are inserted and an “undo” option if the results are not as intended.

 NEW 
Fractional grid refinement - change grid spacing (refinement or coarsening) by a fraction, rather than just whole number – For example; you can choose over a specified model area to convert every 3 rows or columns to 2 rows or columns (or whatever fraction you wish). This is particularly useful for grid smoothing to ensure that grid step sizes aren’t too large.

 NEW  Cell size control - have full control over grid cell size specification during initial grid creation so that grid cell sizes can be set to whole numbers for ease of calculation and reporting.

 CL  Grid quality indicators - Visual indication during grid editing of cells that violate the maximum cell step size, and flexibility to define the cell step size tolerance for each grid, so you can ensure a high quality grid and reduce potential for grid-based dispersion and/or larger computational times. 

Property and Boundary Condition Editing Enhancements

CL  Cross-Section assignment - Assign or edit boundaries and properties directly on cross-sectional grid views to help ensure boundaries/properties are placed exactly where you want.

 CL  Calculated value support - Use calculated values to determine boundary condition attributes – particularly useful for boundaries such as rivers.

 CL  Boundary condition validation - Internal system checks on assigned boundary conditions to ensure that they meet MODFLOW engine requirements – For example; start and ending heads fall within the cell top and bottom. Flex automatically suggests corrective actions for any violations.

 NEW  Multi-segment linear interpolation for boundary condition values - Now you have full control to define linearly interpolated values over a section of a boundary, or multiple segments with different linear interpolations as needed, to simplify assigning the boundary values you want. 

 NEW  Copy/paste and bulk property or boundary value assignment - If you have your values already defined outside of Flex, you can now quickly copy and paste them right into the boundary or property zone dialogues. Need a way to insert the same value in multiple cells? Now you can do that too with one click or keystroke.
 NEW  Visually interactive editor - Would you like to edit boundary or cell values cell-by-cell to improve your model calibration? The new visually interactive editor lets you select a value and see where the cell is located in the grid viewer, or, select a cell in the grid viewer and directly edit the cell values.

Other Improvements

NEW  Subgrid creation - quickly create a new model based on a subgrid from a larger model (including creation of all appropriate boundary conditions) with two mouse clicks. This is particularly useful for creation of local transport models from larger scale flow models.

 CL  DXF support - display 2D or 3D DXFs in any of the Flex viewer windows to use as basemaps and help understand and place simulation results in real-world context.

 CL  Heads from a previous run - use heads files from previous model runs as the starting point for new model runs to reduce solver run times.

 NEW  FlexScript DSL Scripting - Hate the mouse and love your keyboard? Now you can use FlexScript to make quick adjustments or exact replicas of grid designs, property, and boundary specifications without having to click through the user interface.

Version number rebranding

You might have noticed we are also branding Visual MODFLOW with the new version type of 4.0. rather than continuing with “year” branded version numbers. We hope this will make it easier for you to track changes and updates. From now on, new versions will always increment the whole number and minor releases will increment the decimal.

Numerical grid editing
Fractional grid refinement
Cross-sectional assignment
Telescopic Mesh Refinement - local model creation

Visual MODFLOW Flex 4.1

What's new in Visual MODFLOW Flex 4.1?

Enjoy robust upgrades and dynamic enhancements in Visual MODFLOW Flex 4.1 This latest version gives users the ability to utilize key upgraded engines; grid editing updates; property and boundary improvements; enriched visualization abilities, and so much more.

The Waterloo Hydrogeologic development team heard from users around the globe that editing capacity was lacking, so they improved it and added many new user-friendly features, including but not limited to those listed below.

Visualization and Settings

  • 2D/3D View Keyboard Navigation – Navigate in the active 2D or 3D view using the keyboard. Arrows keys pan the view, +/-keys (on the number pad) and page up/page down keys zoom in and out. In an active 3D view, the Shift+arrow up/down keys changes the inclination of the model relative to the horizon and Shift+arrow right/left rotates the model about the vertical axis.
  • Custom Contours – Customize contours in 2D, 3D and Flex Viewers by setting start and finish contour values for contour lines and isolines. You can also specify a contour interval. Changes in one part of the flex Viewer are reflected in other parts.
  • 3D View Setting Defaults – Create and Save project-Specific Default View Settings for each data type in the 3D Viewer.

Workflows

  • Modeling Objectives – Modeling Objectives for Transport Simulations can be changed at any time, not just during initial set-up or conversion.
  • Model Settings for Translate/Run – You can now specify whether individual packages are translated and/or run with the model, which provides the flexibility to use your own packages similar to the advance settings in Classic for model translate/run.

Grid Editing Enhancements

  • Cell size Control for Conceptual Models – Similar to numerical grids, you now have full control over the grid size specification during initial grid creation; you can set grid cell dimensions to whole numbers for ease of calculation and reporting.

Property and Boundary Condition Enhancements

  • LGR Boundary Conditions – Boundary conditions that span the parent/child grid interface(s) in an LGR model can be specified in both the Conceptual and Numerical workflows
  • Dual Domain Mass Transfer – Flex 4.1 now supports dual domain mass transport modeling through the MT3D-MS and MODFLOW-SURFACT transport engines. (See Updated Engines)
  • Unsaturated Zone Flow (UZF) Package – Flex now supports 1-D unsaturated flow associated with the UZF package in MODFLOW-2005.

Updated Engines

  • Upgraded MODFLOW 2005 – Flex is now packaged with MODFLOW-2005 v1.12.00, the latest official USGS version as of the release date of Flex 4.1.
  • Upgraded MODFLOW NWT – Flex is now packaged with MODFLOW-NWT v1.1.2, the latest official USGS version as of the release date of Flex 4.1
  • Added support for MODFLOW-SURFACT – Visual MODFLOW Flex now supports MODFLOW-SURFACT version 4.0, a fully-coupled flow and transport engine developed by HydroGeoLogic, Inc. which features many robust methods and enhanced simulation capabilities for handling complex saturated/unsaturated subsurface flow and transport processes. Based on the USGS modular groundwater flow model, MODFLOW, it supports the following packages:

MODFLOW-SURFACT-CHART-for-website
NOTE: MODFLOW-SURFACT was developed by HydroGeoLogic, INC. and is sold as a separate add-on for Visual MODFLOW Flex. A demo-version that supports model grids of up to 10,000 cells is included for evaluation purposes. Additional packages (e.g. subsidence [SUB], streamflow routing [SFR], etc.) are supported by SURFACT and may be developed outside Flex.

General

  • Undock/Redock Tabs – Tabs can be undocked as separate windows. Simply drag and drop or right-click on the Tab name and select the 'Undock Tab' option and you can place the new window anywhere on your monitor screen(s). Redock a window back to the main program window using drag and drop or right-click and select the 'Dock Tab' option.
  • Explorer Support – Open a Visual MODFLOW Flex .AMD file directly from Windows Explorer.
  • .Net Framework 4.6.1 – Now bundled with Flex installation.
  • About/Splash Screen – Version and build number are displayed on the Splash Screen and on the About Screen.
  • Improved Performance – Improved memory handling and performance enhancements

Defects Addressed

  • Could not edit or define a Boundary Condition when multiple grids were present as part of the same LGR grid.
  • Inconsistency between calculating and displaying leakance in the lake boundary condition when using certain time units.
  • Some PEST runs were not successful due to incorrect observation files.
  • Issue when importing time schedules for recharge package.
  • Translation issue when importing some Visual MODFLOW 2010.1 Classic projects into Flex.
  • Progress bar does not provide adequate feedback when opening large projects.
  • Issue with extracting multiple species from sub-grids for MT3D-MS runs.
  • Toolbox was blank after translating/running the model and clicking Define Properties step.
  • Translation issue in MT3D-MS RC3 file for bulk density values when using inconsistent units.
  • Improved feedback/reporting for certain engine runs that do not converge.

Visual MODFLOW Flex 5.1

What's new in Visual MODFLOW Flex 5.1?

Visual MODFLOW Flex brings together industry-standard codes for groundwater flow and contaminant transport, essential analysis and calibration tools, and stunning 3D visualization capabilities in a single, easy-to-use environment. Experience the new version release of Visual MODFLOW Flex 5.1.

Data Import/Export

  • Surfaces created in Visual MODFLOW Flex can be exported as Surfer ASCII files (.GRD) for use in other Visual MODFLOW Flex projects and other software packages (e.g. Surfer, ArcMap, QGIS).

v51 Surfaces

  • Pumping Wells in Visual MODFLOW Flex numerical models can be exported as text files (.CSV) that can be easily re-imported allowing you to transfer Wells between projects.

Import Pumping Wells

Visualization and Settings

  • Vertical exaggeration in 3D views can be manipulated by keyboard commands.

v51 Keyboard Commands

Packages, Properties, and Boundary Conditions

  • Field values for Properties and Boundary Conditions are available as variables in the Field Calculator.

Expression Builder 1Expression Builder 2

Grid Editing

  • You can now specify which numerical model run(s) are carried over when performing grid edits.

Grid Editing

Defects Addressed

  • In some scenarios (for instance if CHD cells are specified at the very bottom of the model [such as in the Henry model]), the parallel version of SEAWAT may have convergence problems that cannot be resolved by changing solver parameters.
  • SEAWAT engine run output was truncated and formatted incorrectly.
  • Concentration values of -1 in the specified concentration boundary condition (indicating the species should be skipped) were incorrectly translated to the SSM file as 0.
  • Error in translating diffusion arrays to the DSP package when specifying the Multidiffusion option in MT3D-MS or SEAWAT runs.
  • In rare occasions, property zones were set to -1 and uneditable.
  • In some cases, successive model translation times increased due to a memory leak.
  • In ZoneBudget runs, Flex does not read in values for zones that are not directly adjacent to Zone 1.
  • Errors thrown if user skips straight to Translate without selecting an engine.
  • In some cases, changes to stress periods do not update instantly to the translation settings resulting in incorrect translated time discretization and/or output control (.OC) files, following changes.
  • In some cases, PEST results will not update correctly into a new run.
  • An error is shown when user clicks [...] button to change the path to Previous MODFLOW Run HDS file if the HDS file is not present.
  • Hitting Apply in the Settings dialog for a concentration doesn't update the BC view properly.