GMS:MODFLOW 6 SWI Package

From XMS Wiki
(Redirected from GMS:MF6 SWI Package)
Jump to navigationJump to search
Gnome globe current event.png
 MODFLOW 6 is currently in Beta release for GMS
Some features and capabilities of MODFLOW 6 are still in development for GMS.
GMS Icon.png
MODFLOW 6
Models & Tools
GWF Model
GWT Model
Cell Properties Dialog
Zone File
Packages
Flow: GNC, HFB, NPF
GWF: BUY, CHD, CSUB,
DRN, EVT, GHB,
LAK, MAW, MVR,
OBS, RCH,RIV,
SFR, STO, UZF,
WEL
GWT: ADV, CNC, DSP
FMI, IC, IST, LKT,
MDT, MST, MVT,
MWT, OBS, SFT,
SRC,SSM, UZT
Other DIS, DISU, DISV,
IMS, OC, TDIS,
PEST
v • e

The Sea Water Intrusion (SWI) package calculates the position of the freshwater / sea water interface in each cell, and calculates flow accordingly. It is accessed by double-clicking on the SWI package under a MODFLOW 6 simulation in the Project Explorer. Opening the Sea Water Intrusion (SWI) package dialog will have the following options:

The Sea Water Intrusion (SWI) package dialog.
  • Sections list – A list of sections that can be turned on or off:
    • GMS OPTIONS – Turn on to make the GMS OPTIONS section visible.
    • COMMENTS – Turn on to make the COMMENTS section visible.
    • OPTIONS – Turn on to make the OPTIONS section visible.
    • GRIDDATA – Turn on to make the GRIDDATA section visible.
  • GMS OPTIONS section
    • Set up DRN, GHB, RCH, and TVA6 – Opens the Set up SWI dialog.
  • COMMENTS section – Enter general alphanumeric comments. Comments entered here get written at the top of the file, preceded by a '#' symbol.
  • OPTIONS section
    • ZETA FILEOUT – If this option is on, when the simulation is run, a binary output file is created containing the zeta surface. This file will be read by GMS and included in the solution as a dataset.
    • TVA6 FILEIN – If this option is on, the SALTWATER_HEAD is specified in a time-array-series file.
    • SALTWATER_HEAD – If this option is on, the specified value will be assigned as the saltwater head used by the SWI Package. During solution of the freshwater flow equation the specified saltwater head will remain fixed. If not specified, and the TVA input option is not specified, then the default value for saltwater head is zero. If the saltwater head option is specified and TVA input is also provided, then the TVA input will override the saltwater head option.
  • GRIDDATA
    • ZETASTRT – The initial (starting) zeta surface for each model cell — that is, the interface elevation at the beginning of the simulation.
      • Binary –
      • Layered — Turn on if there is more than one affected layer. Select the desired layer from the drop down in order to edit the array (if "Array" is selected from the drop-down).
      • 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).
      • If "Array" is selected from the drop-down, a user-editable array appears below the drop-down. Enter a decimal Factor value to the right of the drop-down. The individual elements of the array are multiplied by the factor value after they are read.
      • Dataset to Array... — Click to open the Select Dataset dialog. Select the desired database(s) in this dialog.

Set Up SWI Dialog

The Set up SWI dialog shows options for setting up the SWI package.

  • Sea level time series (.csv) – The ... button allows for a comma separated values (*.csv) file to be selected, which contains the sea level rise over time. The file should have the dates in the first column, and the sea water rise in the second column. For example:
    asdf
0 0
3652.5 0.1
3652.5 0.2
3652.5 0.3

The dates can be specified as a date string if the TDIS package has the START_DATE_TIME option turned on.

1/1/2020 0
1/1/2030 0.1
1/1/2040 0.2
1/1/2050 0.3


  • Create GHB package – If this option is on, a GHB package is created to model how salt water moves between the sea and the ground surface, and to account for inundation of areas formerly above sea level. The package is created such that a GHB boundary condition is added to a cell when the sea level rises above the cell top elevation. Thus, later stress periods will have more GHB boundary conditions as the sea level rises.
  • GHB Conductance – The conductance value (COND) used for every GHB boundary condition. Typically this is set to an arbitrarily high value so that flow is not restricted.
  • Create DRN package – If this option is on, a DRN package is created to model the effects of the fresh water table rising above the ground surface due to sea water intrusion below the fresh water. The package is created by adding DRN boundary conditions in all cells where the sea level is below the top of the cell. Thus, later stress periods will have fewer DRN boundary conditions as the sea level rises.
  • DRN Conductance – The conductance value (COND) used for every DRN boundary condition. Typically this is set to an arbitrarily high value so that flow is not restricted.
  • Fix RCH packages – If this option is on, all existing recharge packages are examined to see if recharge is being applied to cells where the sea level is above the top of the cell. If so, a copy of the recharge package is created and recharge is set to zero in these cells.
  • Create SALTWATER_HEAD TVA file – If this option is on, a time-array-series (*.tva) file is created from the Sea level time series and includes SALTWATER_HEAD values over time. The new file is used with the TVA6 FILEIN option in the SWI package, and this option is turned on.

Related Topics
Retrieved from "https://www.xmswiki.com/index.php?title=GMS:MODFLOW_6_SWI_Package&oldid=164484"