User's guide of Proceessing Modflow 5.0

Processing Modflow 103
< Max. band width of AL: This value impacts the amount of memory used by the solver. If
specified as 0, the program will calculate the value as the product of the two smallest grid
dimensions, which is an upper limit.
< Head change closure criterion [L]: If iterating, iteration stops when the absolute value of
head change at every node is less than or equal to this value. The criterion is not used when
not iterating, but a value must always be specified.
Fig. 3.29 The Direct Solution (DE45) dialog box
< Printout From the Solver: If the option All available information is selected, the
maximum head change and residual (positive or negative) are saved in the run record file
OUTPUT.DAT for each iteration of a time step whenever the time step is an even multiple
of Printout Interval. If the option The number of iterations only is checked, the printout
of maximum head change and residual is suppressed. Select the option None to suppress all
printout from the solver. A positive integer is required by Printout Interval.
< Problem Type: The choice of problem type affects the efficiency of solution; significant
work can be avoided if it is known that A_ remains constant all or part of the time.
Linear indicates that the flow equations are linear. To meet the linearity requirement, all
model layers must be confined, and there must be no formulations that change based upon
head (such as seepage from a river changing from head dependent flow to a constant flow
when head drops below the bottom of the riverbed). Examples of non-linearity are cases
with riverbed conductance, drain conductance, maximum evapotranspiration rate,
evapotranspiration extinction depth, gerneral-head boundary conductance and reservior-bed
conductance.
Nonlinear indicates that a non-linear flow equation is being solved, which means that
some terms in A_ depend on simulated head. Example of head-dependent terms in A_ are
3.6.1 MODFLOW