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It is sometimes necessary or insightful to develop two-dimensional flow models in the vertical plane (e.g., for simulating vertical circulation of regional groundwater flow, visualizing flow around a subsurface barrier or infrastructure, or understanding groundwater delivery mechanisms to surface water bodies). These types of models are called often called vertical cross-section or vertical profile models

MAGNET offers two quick and easy ways to build a vertical profile model:

1) When the water table is known or prescribed, the y-coordinate can be treated as the vertical dimension, and a line feature is used to represent the water table (water table elevation equals y-coordinate)

2) When the water table is not known ahead of time (but rather, is part of the solution), a "slice" or cross-section of a 3D model can be analyzed and visualized. 

Graphic 1: Example of a Simple 2D Vertical Profile Model with a prescribed water table (following y-coordinate).

Graphic 2Example of "3D Slice" Vertical Profile Model where the water table is part of the solution (more general).

TASKS

  1. Create a synthetic example of a vertical profile in the case where the water table is known / prescribed. You may consider reproducing one of the animations shown in Vertical Regional Circulation video library
  2. Create a synthetic example of a vertical profile model as a "slice" of a 3D model. You may want to visit one of the short problems in the MAGNET Groundwater Curriculum for inspiration, e.g., Flow Through an Embankment or Streamflow Depletion.
  3. Discuss the relative advantages and disadvantages of the two different approaches. 

MAGNET/Modeling Hints

  • Use ‘Synthetic mode’ in MAGNET to create a model domain.
  • To create a 2D vertical profile model in the case of a known water table, use a line feature and the 'Equal to Y (e.g., Water Table)' option to delineate the water table surface toward the top of the model domain. 
  • After your initial simulation, you can "clean up" the display by then making the space above the water table inactive with a zone feature ( 'Flow Properties' tab > 'Zone Type' > 'Inactive' ).
  • Use a relatively large NX (e.g., 100) to resolve the water table shapes.