ModelMuse: Quasi-3D Models

Video Transcript
Download Video
Right-click and save to download

Detailed Description

This video describes how to set up quasi-3D models in ModelMuse.
 

Details

Image Dimensions: 800 x 600

Date Taken:

Length: 00:02:41

Location Taken: US

Transcript

The letters "USGS" and the words "Science for a Changing World" appear in green and fade to black.
This video describes how to set up quasi-3D models in ModelMuse.
In a quasi-3D model, some of the layers aren't simulated. This is an example of such a model.
I open the MODFLOW layer groups dialog box and the middle layer is a non simulated layer.
That means when I export the MODFLOW input files, there will only be two layers in the model.
The middle layer won't be included because it is a non-simulated layer.
However, the vertical hydraulic conductivity of the middle layer will be used to calculate the conductance between the top and bottom layers.
Let's look at what the vertical hydraulic of the middle layer is.
I'm going to look at Kz.
Color the grid with the Kz dataset.
And I'll open the Grid Value dialog box
You will be able to see the grid values here as I move the cursor over the grid.
I'm going to move it over the front view of the model.
The top layer has a vertical hydraulic conductivity of 10^ -4.
The middle layer has a vertical hydraulic conductivity of 10^-7.
The bottom layer has a vertical hydraulic conductivity of 10^ -4.
The vertical hydraulic conductivity the middle layer is quite low compared to the top and bottom layers.
Because of its low vertical hydraulic conductivity, flow through the middle layer will be nearly vertical.
In a quasi-3D model flow across the non-simulated layers is assumed to be perfectly vertical.
With such a high contrast in vertical hydraulic conductivity, that assumption is sufficiently accurate for this model.
You would not want to use a quasi-3D model if you were simulating solute transport or if you needed to specify a boundary condition in the layer with low hydraulic conductivity.
In addition, quasi-3D are not possible when modeling with PHAST.
The letters "USGS" and the words "Science for a Changing World" appear in green.