SIM-TDIS

Structure of Blocks

FOR EACH SIMULATION

    BEGIN OPTIONS
      [TIME_UNITS <time_units>]
      [START_DATE_TIME <start_date_time>]
      [ATS6 FILEIN <ats6_filename>]
    END OPTIONS

    BEGIN DIMENSIONS
      NPER <nper>
    END DIMENSIONS

FOR ANY STRESS PERIOD

    BEGIN PERIODDATA
      <perlen> <nstp> <tsmult>
      <perlen> <nstp> <tsmult>
      ...
    END PERIODDATA

Explanation of Variables

Block: OPTIONS

  • time_units is the time units of the simulation. This is a text string that is used as a label within model output files. Values for time_units may be “unknown”, “seconds”, “minutes”, “hours”, “days”, or “years”. The default time unit is “unknown”.

  • start_date_time is the starting date and time of the simulation. This is a text string that is used as a label within the simulation list file. The value has no effect on the simulation. The recommended format for the starting date and time is described at https://www.w3.org/TR/NOTE-datetime.

  • ATS6 keyword to specify that record corresponds to an adaptive time step (ATS) input file. The behavior of ATS and a description of the input file is provided separately.

  • FILEIN keyword to specify that an input filename is expected next.

  • ats6_filename defines an adaptive time step (ATS) input file defining ATS controls. Records in the ATS file can be used to override the time step behavior for selected stress periods.

Block: DIMENSIONS

  • nper is the number of stress periods for the simulation.

Block: PERIODDATA

  • perlen is the length of a stress period.

  • nstp is the number of time steps in a stress period.

  • tsmult is the multiplier for the length of successive time steps. The length of a time step is calculated by multiplying the length of the previous time step by TSMULT. The length of the first time step, Delta t_1, is related to PERLEN, NSTP, and TSMULT by the relation Delta t_1= perlen frac{tsmult - 1}{tsmultnstp-1}.

Example Input File

    # Comment for this TDIS input file
    
    BEGIN OPTIONS
      TIME_UNITS DAYS
    END OPTIONS
    
    BEGIN DIMENSIONS
      NPER 2
    END DIMENSIONS
    
    BEGIN PERIODDATA
       365.00  1 1.0   Items: PERLEN NSTP TSMULT
       365.00 10 1.2   Items: PERLEN NSTP TSMULT
    END PERIODDATA