Visual MODFLOW Flex 10.0 Product Release

March 21, 2024

Visual MODFLOW Flex – Integrated Conceptual & Numerical Groundwater Modeling Software

On March 27, 2024, we released Visual MODFLOW Flex 10.0, the latest version of the popular graphical user interface that brings together industry-standard codes for groundwater flow and contaminant transport, essential analysis and calibration tools, and stunning 3D visualization capabilities in a single environment. The conceptual model approach which is unique to Visual MODFLOW Flex in groundwater modeling user interfaces allows you to:

  • Build a conceptual model of the groundwater system, prior to the simulation – Geologic formation structures, hydrogeologic properties, and boundary conditions are all designed outside the model grid or mesh; this allows the flexibility to adjust your interpretation of the groundwater system before applying a discretization method and converting to a numerical model.

  • Build the model with minimal data pre-processing required – Working with grid-independent data allows you to maximize the use of your existing GIS data and incorporate physical geology and geographic conditions before designing a grid or mesh.

  • Generate and simulate regional and local-scaled models – With support for unstructured Voronoi and Quadtree grids and local grid refinement (LGR), you can design localized/refined grids around areas of interest, directly within the conceptual model environment. With the ability to easily extract subgrids, calculated heads from a regional model can also be used as boundary conditions for local-scaled models.

  • Design the correct model faster – The grid-independent raw data is left intact and is not defined by grid cells or mesh elements when modifying the data and project objective. This allows you to generate multiple numerical models from the same conceptual model.

  • Make changes to the model data and immediately see results – The conceptual model environment provides simultaneous 2D and 3D views which are updated whenever changes to the data are made.

Visual MODFLOW Flex Improvements

Version 10.0 of Visual MODFLOW Flex includes the following improvements:

PEST Workflow Improvements

Visual MODFLOW Flex includes significant upgrades to the PEST workflow:

  • Workflow Steps: The PEST workflow includes a number of new and improved workflow steps:

    • Define Observations: add flux observations and improved usability for assigning observation groups, observations, and weights

    • Define Property Parameters: add recharge (RCH), evapotranspiration (EVT), and unsaturated zone flow (UZF) property parameters to the PEST run

    • Define Kriging Variograms: an optional new setting that allows PEST utilities to automatically calculate the kriging variograms based on the density of pilot points

    • Select PEST Variant: you can select which variant of PEST to use (PEST v17.5, PEST_HP)

    • PEST Control settings: define/edit settings for the PEST run including for the Objective Function, Parameter Updates, Iterations, Marquardt Lambda, Singular Value Decomposition, etc.

    • Parameter Estimation: Stop and Restart PEST Runs
  • Support for PEST_HP: significantly speed up PEST runs by using PEST_HP, a parallelized version of PEST that can make use of multiple cores on your machine

  • Support for MODFLOW-6: include structured finite difference or unstructured MODFLOW-6  flow models in a PEST workflow

  • Pilot Point Interpolation: The scripts in a PEST run that link parameter updates in PEST to pilot points include several improvements:

    • Pilot point interpolation makes use of the PLPROC utility for improved performance and clarity of the script files
    • Optional automated calculation of the kriging variogram parameters based on the density of pilot points
  • Improved Validation: Visual MODFLOW Flex includes additional checks in the PEST workflow to reduce input errors

  • Observation Weights: automatically calculate observation weights so that observation groups contribute equally to the initial objective function with and without normalizing observations using the target residual

Color Handling

Visual MODFLOW Flex includes the following improvements for visualization:

  • Color Ramps: objects with distributed values such as surfaces, model properties, boundary conditions, and model outputs can be rendered using predefined or custom color ramps:

    • Define a list of custom, linearly distributed, logarithmically distributed, or custom values and associated colorsSelect from a list of predefined, custom, or imported color ramps
    • Include optional hard breaks/color stops in a ramp to render an abrupt break in colors when values cross a specified threshold (e.g. positive/negative or above/below a regulatory limit)
Color Handling in MODFLOW 10.0
  • Manage Color Ramps:

    • Visual MODFLOW Flex includes over a dozen predefined color ramps or you can create your own custom color rampYou can import color ramps using the color map (.clr) file format supported in other applications such as QGIS, ArcPro, and Surfer
    • The project palette variables include all color fill settings including colors and values
  • Project Palette: the project palette includes all value and color settings so you have more fine control over rendering

Boundary Condition and Properties

Visual MODFLOW Flex includes the following improvements for working with your models:

  • MAW and MWT Package Support: Support for the multi-aquifer well (MAW) and multi-aquifer well transport (MWT) packages in MODFLOW-6 models.

    • Create or import MAW/MWT wells
    • Dynamically switch between supported well models (WEL/MNW1/MNW2/MAW)

    • Import and edit well information including head loss, well skin, and pump constraint parameters supported in the MAW package
  • Conceptual Wells: pumping wells in the unstructured grid workflow are grid-independent, conceptual, and support the WEL or MAW well model.

  • Flux Observations: Support for boundary condition flux observations for unstructured grid models (MODFLOW-6 and MODFLOW-USG)

  • Assign Properties: the assign properties in the unstructured grid workflow includes additional tools for setting property zones and values similar to the tools available in the workflow for structured finite difference grid models

  • Layer Properties: the translation step in the unstructured grid workflow includes layer type settings for MODFLOW-USG and MODFLOW-6 models

Performance, Usability, and Other Enhancements

Visual MODFLOW Flex includes the following improvements for working with your models:

  • Performance Enhancements:

    • Assigning time steps to models with many stress periods Model translation for MODFLOW-6 models with many stress periods

    • Converting a conceptual model to an unstructured Q-grid model with many cells

    • Applying/saving changes to model properties for an unstructured grid model with many cells
  • The following features can be exported from Visual MODFLOW Flex:

    • Model outputs including heads, concentrations, and drawdowns as contours for unstructured grid models (MODFLOW-6 and MODFLOW-USG)boundary conditions as points or polygons for unstructured grids
    • Calibration dashboard charts as images

  • SAMG solver:

    • Updated versions of the SAMG solver for the MODFLOW-USG and MODFLOW-6 engines

    • Available in the Pro (serial-SAMG) and Premium (multi-core-SAMG)

    • New Add-on available for Visual MODFLOW Flex Premium Edition that includes a more advanced edition called SAMG+ that also handles models with transport and CLN
  • The view will be centered on the mouse pointer when using the mouse wheel to zoom in/out in 2D views

  • The View/Edit Grid step for structured finite difference grid numerical workflows includes a toolbar with buttons to interact with the view

  • The Translation Step in numerical workflows includes a general setting to translate models using external arrays/files to facilitate working with PEST

  • The output times table in the Output Control settings page for MT3D-MS, RT3D, or SEAWAT models will expand if you can paste more output times than there are rows

  • Consolidate boundary conditions in a model into a single boundary condition

  • Intermediary layer elevations automatically update after changing the min and max elevations or the number of layers when defining the grid in a numerical workflow

  • Some informational messages that appear repeatedly have settings to automatically suppress them

For a full version history, see the Visual MODFLOW Flex readme file.