User's guide of Proceessing Modflow 5.0

Processing Modflow 75
steady state simulation over several stress periods. In this case, a steady state solution is
calculated for each stress period.
< Save and Load: Using these buttons, you can save or load the contents of the table in or from
a time parameter file. The format of the time parameter file is given in Appendix 2.
Initial Hydraulic Heads
MODFLOW requires initial hydraulic heads at the beginning of a flow simulation. Initial hydraulic
heads at fixed-head cells will be kept constant during the flow simulation.
For transient flow simulations, the initial heads must be the actual values. For steady-state flow
simulations, the initial heads are starting guessed values for the iterative equation solvers. The
heads at the fixed-head cells must be the actual values while all other initial heads can be set arbitrarily.
For an uncofined layer (layer type 1 or 3), the initial hydraulic head of a fixed-head cell must be
higher than the elevation of the cell bottom, because MODFLOW does not convert a dry fixed-head
cell to an inactive cell. If any constant-head cell becomes dry, MODFLOW will stop the flow
simulation and write a message "CONSTANT-HEAD CELL WENT DRY - SIMULATION
ABORTED" into the run record file OUTPUT.DAT.
Both MT3D and MOC3D require initial concentration at the beginning of a transport simulation.
Initial concentration at constant-concentration cells will be kept constant during the simulation.
Constant-concentration cells can be used to simulate contaminated areas with a fixed concentration.
Note that constant-concentration boundary condition is not implemented in MOC3D.
Boreholes and Observations...
The options of the Boreholes and Observations dialog box are grouped under two tabs - Boreholes
and Observations.
< Boreholes: The real-world coordinates (eastings (x), northings (y)) and the layer number of
each borehole are given in the table. A borehole is active if the Active flag is checked. While
you are editing your model data using the Data Editor, active boreholes and the corresponding
borehole name can be displayed. After a simulation, PMWIN will interpolate the simulation
results to the active boreholes. So, you may use the Graph Viewer (Tools