User's guide of Proceessing Modflow 5.0

Processing Modflow 39
< To assign the input rate of contaminants
1. Choose MOC3D < Sink/Source Concentration < Recharge from the Models menu.
3
2. Assign 12500 [µg/m ] to the cells within the contaminated area.
This value is the concentration associated with the recharge flux. Since the recharge rate is
-9 3 2 -4 2
8 × 10 [m /m /s] and the dissolution rate is 1 × 10 [µg/s/m ], the concentration associated
-4 -9 3
with the recharge flux is 1 × 10 / 8 × 10 = 12500 [µg/m ]
3. Choose Leave Editor from the File menu or click the leave editor button .
< To assign the parameters for the advective transport
1. Choose MOC3D < Advection... from the Models menu.
A Parameters for Advection Transport (MOC3D) dialog box appears. Enter the values
as shown in Fig. 2.30 into the dialog box, select Bilinear (X, Y directions) for the
interpolation scheme for particle velocity. As noted by Konikow et al. (1996), if
transmissivity within a layer is homogeneous or smoothly varying, bilinear interpolation of
velocity yields more realistic pathlines for a given discretization than does linear
interpolation.
2. Click OK to close the dialog box.
Fig. 2.30 The Parameters for Advective Transport dialog box.
< To assign the parameters for dispersion and chemical reaction
1. Choose MOC3D < Dispersion & Chemical Reaction... from the Models menu.
A Dispersion / Chemical Reaction (MOC3D) dialog box appears. Check Simulate
Dispersion and enter the values as shown in Fig. 2.31. Note that the paramters for
dispersion and chemical reaction are the same for each layer.
2. Click OK to close the dialog box.
2.2.2 Perform Transport Simulation with MOC3D