User's guide of Proceessing Modflow 5.0

Processing Modflow 191
< Pathline Colors:
simulation. In this case, particles will be stopped immediately after the start. Note that
you cannot start backward particle tracking from the end of a transient flow
simulation, rather you can only start particles from the beginning of the last
simulation time step. If the simulation time limit is reached and this option is not
checked, PMPATH calculates flowlines by assuming that the flow field of the first
or last time step is steady-state.
Normally, the color of each pathline is the same as the color of each particle. It is sometimes
useful when the colors of pathlines are distinguished by layers instead of particles. There are
two ways to change the color of each layer:
1. Change the color individually
a. Click on a colored cell of the table, a button will appear in the cell.
b. Click on the button then select a color from a Color dialog box.
2. Change the color using the Color Spectrum dialog box
Using the Color Spectrum dialog box, the color of each layer can be automatically
assigned so you get a gradational change from one color to another.
a. Click the header button Color. A Color Spectrum dialog box appears.
b. In the Color Spectrum dialog box, click the Minimum Color button to display a
Color dialog box. In the Color dialog box, select a color and click OK. Repeat this
procedure for the Maximum Color button.
c. In the Color Spectrum dialog box, click OK. A gradation of colors from the
minimum to the maximum is assigned to each layer.
< RCH/EVT Options:
- Recharge: The option is disabled if recharge is not used. MODFLOW treats recharge as
an internal distributed source of a cell and does not assign it to any of the six cell faces.
The distributed source approximation is usually only appropriate for two-dimensional
areal flow models. The flow velocity across the top face of a cell in the top model layer
would be zero, if the existing recharge is not assigned to the top face. Consequently,
particles cannot be tracked backwards to the top face.
In PMPATH, recharge may be treated as a distributed source, or assigned to the top
face or bottom face of a cell by selecting a corresponding option from the dialog box.
Recharge will be assigned to the top face and "negative" recharge will be assigned to the
bottom face, if the option Assign recharge to top and bottom cell faces is chosen.
- Evapotranspiration: The option is disabled if evapotranspiration is not used. Similar
to Recharge, evapotranspiration can be assigned to top face of a cell or treated as a
distributed sink.
4.3 PMPATH Options Menu