GWF-EVT
Structure of Blocks
FOR EACH SIMULATION
BEGIN OPTIONS
[FIXED_CELL]
[AUXILIARY <auxiliary(naux)>]
[AUXMULTNAME <auxmultname>]
[BOUNDNAMES]
[PRINT_INPUT]
[PRINT_FLOWS]
[SAVE_FLOWS]
[TS6 FILEIN <ts6_filename>]
[OBS6 FILEIN <obs6_filename>]
[SURF_RATE_SPECIFIED]
END OPTIONS
BEGIN DIMENSIONS
MAXBOUND <maxbound>
NSEG <nseg>
END DIMENSIONS
FOR ANY STRESS PERIOD
BEGIN PERIOD <iper>
<cellid(ncelldim)> <surface> <rate> <depth> [<pxdp(nseg-1)>] [<petm(nseg-1)>] [<petm0>] [<aux(naux)>] [<boundname>]
<cellid(ncelldim)> <surface> <rate> <depth> [<pxdp(nseg-1)>] [<petm(nseg-1)>] [<petm0>] [<aux(naux)>] [<boundname>]
...
END PERIOD
Explanation of Variables
Block: OPTIONS
FIXED_CELLindicates that evapotranspiration will not be reassigned to a cell underlying the cell specified in the list if the specified cell is inactive.auxiliarydefines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.auxmultnamename of auxiliary variable to be used as multiplier of evapotranspiration rate.BOUNDNAMESkeyword to indicate that boundary names may be provided with the list of evapotranspiration cells.PRINT_INPUTkeyword to indicate that the list of evapotranspiration information will be written to the listing file immediately after it is read.PRINT_FLOWSkeyword to indicate that the list of evapotranspiration flow rates will be printed to the listing file for every stress period time step in which “BUDGET PRINT” is specified in Output Control. If there is no Output Control option and “PRINT_FLOWS” is specified, then flow rates are printed for the last time step of each stress period.SAVE_FLOWSkeyword to indicate that evapotranspiration flow terms will be written to the file specified with “BUDGET FILEOUT” in Output Control.TS6keyword to specify that record corresponds to a time-series file.FILEINkeyword to specify that an input filename is expected next.ts6_filenamedefines 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.OBS6keyword to specify that record corresponds to an observations file.obs6_filenamename of input file to define observations for the Evapotranspiration package. See the “Observation utility” section for instructions for preparing observation input files. Tables ref{table:gwf-obstypetable} and ref{table:gwt-obstypetable} lists observation type(s) supported by the Evapotranspiration package.SURF_RATE_SPECIFIEDindicates that the proportion of the evapotranspiration rate at the ET surface will be specified as PETM0 in list input.
Block: DIMENSIONS
maxboundinteger value specifying the maximum number of evapotranspiration cells cells that will be specified for use during any stress period.nsegnumber of ET segments. Default is one. When NSEG is greater than 1, the PXDP and PETM arrays must be of size NSEG - 1 and be listed in order from the uppermost segment down. Values for PXDP must be listed first followed by the values for PETM. PXDP defines the extinction-depth proportion at the bottom of a segment. PETM defines the proportion of the maximum ET flux rate at the bottom of a segment.
Block: PERIOD
iperinteger 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.cellidis 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.surfaceis the elevation of the ET surface (L). If the Options block includes a TIMESERIESFILE 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.rateis the maximum ET flux rate (LT-1). If the Options block includes a TIMESERIESFILE 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.depthis the ET extinction depth (L). If the Options block includes a TIMESERIESFILE 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.pxdpis the proportion of the ET extinction depth at the bottom of a segment (dimensionless). pxdp is an array of size (nseg - 1). Values in pxdp must be greater than 0.0 and less than 1.0. pxdp values for a cell must increase monotonically. If the Options block includes a TIMESERIESFILE 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.petmis the proportion of the maximum ET flux rate at the bottom of a segment (dimensionless). petm is an array of size (nseg - 1). If the Options block includes a TIMESERIESFILE 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.petm0is the proportion of the maximum ET flux rate that will apply when head is at or above the ET surface (dimensionless). PETM0 is read only when the SURF_RATE_SPECIFIED option is used. If the Options block includes a TIMESERIESFILE 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.auxrepresents the values of the auxiliary variables for each evapotranspiration. The values of auxiliary variables must be present for each evapotranspiration. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE 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.boundnamename of the evapotranspiration cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
Example Input File
Example 1
# Example for structured model with list-based input
BEGIN OPTIONS
AUXNAMES Mult
BOUNDNAMES
TS6 FILEIN EtRate.ts
# Note: Time-series file EtRate.ts defines time series et_rate
AUXMULTNAME Mult
PRINT_INPUT
BEGIN DIMENSIONS
MAXBOUND 10
NSEG 3
END DIMENSIONS
BEGIN PERIOD 1
# Lay Row Col SURFACE RATE DEPTH PXDP1 PXDP2 PETM1 PETM2 Mult Name
1 1 13 110.0 et_rate 10.0 0.2 0.5 0.3 0.1 0.2 ET-1
1 2 13 110.0 et_rate 10.0 0.2 0.5 0.3 0.1 0.4 ET-2
1 3 13 110.0 et_rate 10.0 0.2 0.5 0.3 0.1 0.6 ET-3
1 4 13 110.0 et_rate 10.0 0.2 0.5 0.3 0.1 0.8 ET-4
1 5 13 110.0 2.e-2 10.0 0.2 0.5 0.3 0.1 1.0 ET-5
1 6 13 110.0 2.e-2 10.0 0.2 0.5 0.3 0.1 1.0 ET-6
1 7 13 110.0 2.e-2 10.0 0.2 0.5 0.3 0.1 0.7 ET-7
1 8 13 110.0 2.e-2 10.0 0.2 0.5 0.3 0.1 0.5 ET-8
1 9 13 110.0 2.e-2 10.0 0.2 0.5 0.3 0.1 0.3 ET-9
1 10 13 110.0 et_rate 10.0 0.2 0.5 0.3 0.1 0.1 ET-10
END PERIOD
Example 2
BEGIN OPTIONS
READASARRAYS
AUXILIARY var1 var2
PRINT_INPUT
PRINT_FLOWS
SAVE_FLOWS
END OPTIONS
BEGIN PERIOD 1
#For a structured grid, IEVT defaults to model
# layer 1, so no need to enter IEVT here.
#ET surface elevation
SURFACE
constant 150.0
#Maximum ET rate
RATE
constant 0.007
#ET extinction depth
DEPTH
constant 15.0
#auxiliary variable (var1) array
var1
constant 100.0
#auxiliary variable (var2) array
var2
constant 0.0
END PERIOD
Available Observation Types
| Stress Package | Observation Type | ID1 | ID2 | Description |
|---|---|---|---|---|
| EVT | evt | cellid or boundname | -- | Flow from the groundwater system through an evapotranspiration boundary or group of evapotranspiration boundaries. |
Example Observation Input File
BEGIN OPTIONS
PRINT_INPUT
END OPTIONS
BEGIN CONTINUOUS FILEOUT my_model.evt.csv
et1-1 EVT 1 1 1
et1-2 EVT 1 1 2
et2-1 EVT 1 2 1
et2-2 EVT 1 2 2
et2-3 EVT 1 2 3
END CONTINUOUS