UTL-TVS

Structure of Blocks

FOR EACH SIMULATION

    BEGIN OPTIONS
      [DISABLE_STORAGE_CHANGE_INTEGRATION]
      [PRINT_INPUT]
      [TS6 FILEIN <ts6_filename>]
    END OPTIONS

FOR ANY STRESS PERIOD

    BEGIN PERIOD <iper>
      <cellid(ncelldim)> <tvssetting>
      <cellid(ncelldim)> <tvssetting>
      ...
    END PERIOD

Explanation of Variables

Block: OPTIONS

DISABLE_STORAGE_CHANGE_INTEGRATION keyword that deactivates inclusion of storage derivative terms in the STO package matrix formulation. In the absence of this keyword (the default), the groundwater storage formulation will be modified to correctly adjust heads based on transient variations in stored water volumes arising from changes to SS and SY properties.
PRINT_INPUT keyword to indicate that information for each change to a storage property in a cell will be written to the model listing file.
TS6 keyword to specify that record corresponds to a time-series file.
FILEIN keyword to specify that an input filename is expected next.
ts6_filename defines a time-series file defining time series that can be used to assign time-varying values. See the “Time-Variable Input” section for instructions on using the time-series capability.

Block: PERIOD

iper integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
cellid is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
tvssetting line of information that is parsed into a property name keyword and values. Property name keywords that can be used to start the TVSSETTING string include: SS and SY.
```
  SS <ss>
  SY <sy>
```
ss is the new value to be assigned as the cell’s specific storage (or storage coefficient if the STORAGECOEFFICIENT STO package option is specified) from the start of the specified stress period, as per SS in the STO package. Specific storage values must be greater than or equal to 0. If the OPTIONS block includes a TS6 entry (see the “Time-Variable Input” section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
sy is the new value to be assigned as the cell’s specific yield from the start of the specified stress period, as per SY in the STO package. Specific yield values must be greater than or equal to 0. If the OPTIONS block includes a TS6 entry (see the “Time-Variable Input” section), values can be obtained from a time series by entering the time-series name in place of a numeric value.

Example Input File

    BEGIN OPTIONS
      TS6 FILEIN tvs_cells.ts
      # Note: Time-series file tvs_cells.ts defines time series cells_sy
    END OPTIONS
    
    # Cell 45 will have its SS value changed to 1e-6 in the first time step of
    # stress period 2, and changed once more to 1e-7 in the first time step of
    # stress period 4.
    #
    # Cells 188 and 291 will have their respective SY values changed according
    # to the time series cells_sy specified in the file tvs_cells.ts. Note that
    # these values may continue to change beyond stress period 2, depending on
    # the duration of the time series cells_sy.
    #
    # No changes are made in stress period 1 due to an absence of a block
    # for that period; cells maintain the initial property values specified in
    # the STO package for the entirety of that period.
    
    BEGIN PERIOD 2
      45  SS  1e-6
      188 SY  cells_sy
      291 SY  cells_sy
    END PERIOD
    
    BEGIN PERIOD 4
      45  SS  1e-7
    END PERIOD
    
    # After the last specified change (or after the last specified time record,
    # when a time series is used), each affected cell will retain its latest
    # changed value for the remainder of the simulation.