User's guide of Proceessing Modflow 5.0

242 Processing Modflow
riverbed hydraulic conductance (eq. 3.21), the hydraulic conductance term of each GHB cell is
C = K @ A / L, where K is the (horizontal) hydraulic conductivity, L is the distance from the
b
actual fixed-head boundary to the modelled GHB cell, and A is the area of the cell face, which
is perpenticular to the groundwater flow in the un-modelled area. For this example C = (T/10)
2
@ (100 @ 10) / 1000 = 0.001 m /s.
Fig. 6.19 shows the calculated contours. For comparison, the entire aquifer is modelled with
the east and west fixed-head boundaries and the result is shown in Fig. 6.20. The model is saved
in the folder \pm5\examples\basic\basic2a\.
Fig. 6.19 Calculated head contours for the west part of the aquifer
Fig. 6.20 Calculated head contours for the entire aquifer
6.2.2 Use of the General-Head Boundary Condition
b