NYPAR = 84
TSTEP = 365 days
PARTVL = 3300 cubic feet
8.4 Definition of the Problem Time Domain
The finite difference formulation of the groundwater
flow governing equation requires that the simulation time
domain be discretized, as does the random walk seepage
transport  algorithm.    The groundwater   elevation of each
head node point is computed at the end of a timestep, gra-
dients at each particle location are computed between time-
steps and all seepage particles injected at the beginning
of each timestep.    Results output represent the conditions
at the end of a timestep.      As discussed in Section 8.3,
shorter timesteps increase the cost of simulation but are
sometimes required for output frequency or head solution
convergence.
The time domain of the simulation is defined by three
parameters:
TSTEP = size of timestep
TIMMAX = ending time of simulation
OUTFRQ = frequency of printout expressed in number of
timesteps
Care should be used in selecting OUTFRQ if several
types of output are selected to prevent vast quantities of
output.   The time parameters used in the sample problem
are:
TSTEP = 365 days
TIMMAX = 18,250 days
OUTFRQ = every 10 timesteps

Golder Associates

March, 19.82

-42-

786085