GMS:MF6 EVT Package

The Evapotranspiration (EVT) Package dialog

The Evapotranspiration (EVT) Package dialog is accessed by double-clicking on the EVT package under a MODFLOW 6 simulation in the Project Explorer. It contains the following sections and options:

• Sections list – A list of sections that can be turned on or off:
  • Comments – Turn on to make the Comments section visible.
  • Options – Turn on to make the Options section visible.
  • PeriodData – Turn on to make the PeriodData section visible. This section is on by default.
• Comments section – Enter general alphanumeric comments. Comments entered here get written at the top of the file, preceded by a '#' symbol.
• Options section – Temporal options and settings:
  • Auxiliary Variables... – Click to bring up the Auxiliary Variables dialog.
  • Time Series... – Click to bring up the Time Series Files dialog.
  • Observations... – Click to bring up the Observation Files dialog.
  • Read as arrays (READASARRAYS) – Click to specify to use array-based input in the EVT package.
  • Do not reassign to underlying cell if cell is inactive (FIXED_CELL) – Click to indicate that evapotranspiration will not be reassigned to a cell underlying the cell specified in the list if the specified cell is inactive.
  • Use auxiliary variable as multiplier (AUXMULTNAME) – Name of auxiliary variable to be used as multiplier of evapotranspiration rate.
  • Print input to listing file (PRINT_INPUT) – Turn on to write the list of evapotranspiration information to the listing file immediately after it is read.
  • Print flows to listing file (PRINT_FLOWS) – Turn on to write the list of evapotranspiration flow rates to the listing file for every stress period time step in which "BUDGET PRINT" is specified in Output Control.
  • Save flows to budget file (SAVE_FLOWS) – Turn on to write evapotranspiration flow terms to the file specified with "BUDGET FILEOUT" in Output Control.
  • Specify petm0 (SURF_RATE_SPECIFIED) – When turned on, indicates that the proportion of the evapotranspiration rate at the ET surface will be specified as PETM0 in list input.
  • Number of ET Segments – Allows the documenting of a value that represents the number of ET segments.
    • Change... – Allows an increase or a decrease of the value within the Number of ET Segments field.
• Periods section – Contains the following:
  • Period drop-down – Use the Increment Up and Down buttons to select the desired period.
  • Define Period – If no period is defined, click to make the spreadsheet editable.
  • Delete Period – Click to delete the existing period.
• Table – Contains four tabs:
  • IEVT – The layer number that defines the layer in each vertical column.
    • "UNDEFINED" – Indicates that there are no definite variables to be applied.
    • "CONSTANT" – If "Constant" is selected from the drop-down, enter a decimal value in the Constant field to be applied to all cells in the layer(s).
    • "ARRAY" – If "Array" is selected from the drop-down, enter an integer in the factor: field to be multiplied to the array after it is read.
    • "TIME-ARRAY SERIES" – Is not supported for IEVT, SURFACE, or DEPTH.
  • SURFACE – The elevation of the ET surface.
    • "UNDEFINED" – Indicates that there are no definite variable to be applied.
    • "CONSTANT" – If "Constant" is selected from the drop-down, enter a decimal value in the Constant field to be applied to all cells in the layer(s).
    • "ARRAY" – If "Array" is selected from the drop-down, enter an integer in the factor: field to be multiplied to the array after it is read.
    • "TIME-ARRAY SERIES" – Is not supported for IEVT, SURFACE, or DEPTH.
  • RATE – The maximum ET flux rate.
    • "UNDEFINED" – Indicates that there are no definite variables to be applied.
    • "CONSTANT" – If "Constant" is selected from the drop-down, enter a decimal value in the Constant field to be applied to all cells in the layer(s).
    • "ARRAY" – If "Array" is selected from the drop-down, enter an integer in the factor: field to be multiplied to the array after it is read.
    • "TIME-ARRAY SERIES" – If "Time-Array Series" is selected from the drop-down, indicate which Time-Array Series is being applied in the Series: field.
  • DEPTH – The ET extinction depth.
    • "UNDEFINED" – Indicates that there are no definite variable to be applied.
    • "CONSTANT" – If "Constant" is selected from the drop-down, enter a decimal value in the Constant field to be applied to all cells in the layer(s).
    • "ARRAY" – If "Array" is selected from the drop-down, enter an integer in the factor: field to be multiplied to the array after it is read.
    • "TIME-ARRAY SERIES" – Is not supported for IEVT, SURFACE, or DEPTH.