GWF-STO
Structure of Blocks
FOR EACH SIMULATION
BEGIN OPTIONS
[SAVE_FLOWS]
[STORAGECOEFFICIENT]
[SS_CONFINED_ONLY]
[TVS6 FILEIN <tvs6_filename>]
[EXPORT_ARRAY_ASCII]
[EXPORT_ARRAY_NETCDF]
END OPTIONS
BEGIN GRIDDATA
ICONVERT [LAYERED]
<iconvert(nodes)> -- READARRAY
SS [LAYERED]
<ss(nodes)> -- READARRAY
SY [LAYERED]
<sy(nodes)> -- READARRAY
END GRIDDATA
FOR ANY STRESS PERIOD
BEGIN PERIOD <iper>
[STEADY-STATE]
[TRANSIENT]
END PERIOD
Explanation of Variables
Block: OPTIONS
SAVE_FLOWS
keyword to indicate that cell-by-cell flow terms will be written to the file specified with “BUDGET SAVE FILE” in Output Control.STORAGECOEFFICIENT
keyword to indicate that the SS array is read as storage coefficient rather than specific storage.SS_CONFINED_ONLY
keyword to indicate that compressible storage is only calculated for a convertible cell (ICONVERT>0) when the cell is under confined conditions (head greater than or equal to the top of the cell). This option has no effect on cells that are marked as being always confined (ICONVERT=0). This option is identical to the approach used to calculate storage changes under confined conditions in MODFLOW-2005.TVS6
keyword to specify that record corresponds to a time-varying storage (TVS) file. The behavior of TVS and a description of the input file is provided separately.FILEIN
keyword to specify that an input filename is expected next.tvs6_filename
defines a time-varying storage (TVS) input file. Records in the TVS file can be used to change specific storage and specific yield properties at specified times or stress periods.EXPORT_ARRAY_ASCII
keyword that specifies input grid arrays, which already support the layered keyword, should be written to layered ascii output files.EXPORT_ARRAY_NETCDF
keyword that specifies input griddata arrays should be written to the model output netcdf file.
Block: GRIDDATA
iconvert
is a flag for each cell that specifies whether or not a cell is convertible for the storage calculation. 0 indicates confined storage is used. >0 indicates confined storage is used when head is above cell top and a mixed formulation of unconfined and confined storage is used when head is below cell top.ss
is specific storage (or the storage coefficient if STORAGECOEFFICIENT is specified as an option). Specific storage values must be greater than or equal to 0. If the CSUB Package is included in the GWF model, specific storage must be zero for every cell.sy
is specific yield. Specific yield values must be greater than or equal to 0. Specific yield does not have to be specified if there are no convertible cells (ICONVERT=0 in every cell).
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.STEADY-STATE
keyword to indicate that stress period IPER is steady-state. Steady-state conditions will apply until the TRANSIENT keyword is specified in a subsequent BEGIN PERIOD block. If the CSUB Package is included in the GWF model, only the first and last stress period can be steady-state.TRANSIENT
keyword to indicate that stress period IPER is transient. Transient conditions will apply until the STEADY-STATE keyword is specified in a subsequent BEGIN PERIOD block.
Example Input File
BEGIN OPTIONS
SAVE_FLOWS
END OPTIONS
BEGIN GRIDDATA
#cell storage conversion 0:confined, 1:convertible
ICONVERT
constant 1
#specific storage (for all model cells)
SS
constant 1.e-5
#specific yield (specified by layer because of LAYERED keyword)
SY LAYERED
constant 0.2
constant 0.15
constant 0.15
END GRIDDATA
BEGIN PERIOD 1
STEADY-STATE
END PERIOD
BEGIN PERIOD 2
TRANSIENT
END PERIOD
#stress period 3 will be transient because
#a BEGIN PERIOD block is not provided.
BEGIN PERIOD 4
STEADY-STATE
END PERIOD