The example model has nine layers. To see how the layer boundaries are defined, select Model|MODFLOW Layer Groups... This brings up the Layer Groups dialog box (fig. 67). Although there are nine layers, only three aquifers are defined. This is because the middle aquifer is divided into seven parts. It is possible to see how the middle layer is divided by clicking on "Middle Aquifer" and selecting the "Discretization" tab. It shows that the layers grow progressively thicker toward the middle of the middle aquifer, and that a number of options exist for how a layer group such as "Middle Aquifer" can be discretized. Click Cancel to close the dialog box.
Figure 67. Layer Groups dialog box in ExampleModel.gpt. |