feat(mf6): Add MODFLOW 6 GWT dfn and classes (#1006)

flopy/mf6/data/dfn/exg-gwfgwt.dfn

@@ -0,0 +1,3 @@
+# --------------------- exg gwfgwt options ---------------------
+
+

flopy/mf6/data/dfn/gwf-buy.dfn

@@ -0,0 +1,145 @@
+# --------------------- gwf buy options ---------------------
+
+block options
+name hhformulation_rhs
+type keyword
+reader urword
+optional true
+longname hh formulation on right-hand side
+description use the variable-density hydraulic head formulation and add off-diagonal terms to the right-hand.  This option will prevent the BUY Package from adding asymmetric terms to the flow matrix.
+
+block options
+name denseref
+type double
+reader urword
+optional true
+longname reference density
+description fluid reference density used in the equation of state.  This value is set to 1000. if not specified as an option.
+default_value 1000.
+
+block options
+name density_filerecord
+type record density fileout densityfile
+shape
+reader urword
+tagged true
+optional true
+longname
+description
+
+block options
+name density
+type keyword
+shape
+in_record true
+reader urword
+tagged true
+optional false
+longname density keyword
+description keyword to specify that record corresponds to density.
+
+block options
+name fileout
+type keyword
+shape
+in_record true
+reader urword
+tagged true
+optional false
+longname file keyword
+description keyword to specify that an output filename is expected next.
+
+block options
+name densityfile
+type string
+preserve_case true
+shape
+in_record true
+reader urword
+tagged false
+optional false
+longname file keyword
+description name of the binary output file to write density information.  The density file has the same format as the head file.  Density values will be written to the density file whenever heads are written to the binary head file.  The settings for controlling head output are contained in the Output Control option.
+
+block options
+name dev_efh_formulation
+type keyword
+reader urword
+optional true
+longname use equivalent freshwater head formulation
+description use the variable-density equivalent freshwater head formulation instead of the hydraulic head head formulation.  This dev option has only been implemented for confined aquifer conditions and should generally not be used.
+
+
+
+# --------------------- gwf buy dimensions ---------------------
+
+block dimensions
+name nrhospecies
+type integer
+reader urword
+optional false
+longname number of species used in density equation of state
+description number of species used in density equation of state.  This value must be one or greater.  The value must be one if concentrations are specified using the CONCENTRATION keyword in the PERIOD block below.
+
+
+# --------------------- gwf buy packagedata ---------------------
+
+block packagedata
+name packagedata
+type recarray irhospec drhodc crhoref modelname auxspeciesname
+shape (nrhospecies)
+reader urword
+longname
+description
+
+block packagedata
+name irhospec
+type integer
+shape
+tagged false
+in_record true
+reader urword
+longname species number for this entry
+description integer value that defines the species number associated with the specified PACKAGEDATA data on the line. IRHOSPECIES must be greater than zero and less than or equal to NRHOSPECIES. Information must be specified for each of the NRHOSPECIES species or the program will terminate with an error.  The program will also terminate with an error if information for a species is specified more than once.
+numeric_index true
+
+block packagedata
+name drhodc
+type double precision
+shape
+tagged false
+in_record true
+reader urword
+longname slope of the density-concentration line
+description real value that defines the slope of the density-concentration line for this species used in the density equation of state.
+
+block packagedata
+name crhoref
+type double precision
+shape
+tagged false
+in_record true
+reader urword
+longname reference concentration value
+description real value that defines the reference concentration value used for this species in the density equation of state.
+
+block packagedata
+name modelname
+type string
+in_record true
+tagged false
+shape
+reader urword
+longname modelname
+description name of GWT model used to simulate a species that will be used in the density equation of state.  This name will have no affect if the simulation does not include a GWT model that corresponds to this GWF model.
+
+block packagedata
+name auxspeciesname
+type string
+in_record true
+tagged false
+shape
+reader urword
+longname modelname
+description name of an auxiliary variable in a GWF stress package that will be used for this species to calculate a density value.  If a density value is needed by the Buoyancy Package then it will use the concentration values in this AUXSPECIESNAME column in the density equation of state.  For advanced stress packages (LAK, SFR, MAW, and UZF) that have an associated advanced transport package (LKT, SFT, MWT, and UZT), the FLOW\_PACKAGE\_AUXILIARY\_NAME option in the advanced transport package can be used to transfer simulated concentrations into the flow package auxiliary variable.  In this manner, the Buoyancy Package can calculate density values for lakes, streams, multi-aquifer wells, and unsaturated zone flow cells using simulated concentrations.
+

flopy/mf6/data/dfn/gwf-dis.dfn

@@ -117,6 +117,6 @@ reader readarray
 layered true
 optional true
 longname idomain existence array
-description is an optional array that characterizes the existence status of a cell.  If the IDOMAIN array is not specified, then all model cells exist within the solution.  If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation.  Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution.  If the IDOMAIN value for a cell is 1, the cell exists in the simulation.  If the IDOMAIN value for a cell is -1, the cell does not exist in the simulation.  Furthermore, the first existing cell above will be connected to the first existing cell below.  This type of cell is referred to as a ``vertical pass through'' cell.
+description is an optional array that characterizes the existence status of a cell.  If the IDOMAIN array is not specified, then all model cells exist within the solution.  If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation.  Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution.  If the IDOMAIN value for a cell is 1 or greater, the cell exists in the simulation.  If the IDOMAIN value for a cell is -1, the cell does not exist in the simulation.  Furthermore, the first existing cell above will be connected to the first existing cell below.  This type of cell is referred to as a ``vertical pass through'' cell.
 
 

flopy/mf6/data/dfn/gwf-disu.dfn

@@ -100,7 +100,7 @@ reader readarray
 layered false
 optional true
 longname idomain existence array
-description is an optional array that characterizes the existence status of a cell.  If the IDOMAIN array is not specified, then all model cells exist within the solution.  If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation.  Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution.  If the IDOMAIN value for a cell is 1, the cell exists in the simulation.  IDOMAIN values of -1 cannot be specified for the DISU Package.
+description is an optional array that characterizes the existence status of a cell.  If the IDOMAIN array is not specified, then all model cells exist within the solution.  If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation.  Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution.  If the IDOMAIN value for a cell is 1 or greater, the cell exists in the simulation.  IDOMAIN values of -1 cannot be specified for the DISU Package.
 
 # --------------------- gwf disu connectiondata ---------------------
 

flopy/mf6/data/dfn/gwf-disv.dfn

@@ -93,7 +93,7 @@ reader readarray
 layered true
 optional true
 longname idomain existence array
-description is an optional array that characterizes the existence status of a cell.  If the IDOMAIN array is not specified, then all model cells exist within the solution.  If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation.  Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution.  If the IDOMAIN value for a cell is 1, the cell exists in the simulation.  If the IDOMAIN value for a cell is -1, the cell does not exist in the simulation.  Furthermore, the first existing cell above will be connected to the first existing cell below.  This type of cell is referred to as a ``vertical pass through'' cell.
+description is an optional array that characterizes the existence status of a cell.  If the IDOMAIN array is not specified, then all model cells exist within the solution.  If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation.  Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution.  If the IDOMAIN value for a cell is 1 or greater, the cell exists in the simulation.  If the IDOMAIN value for a cell is -1, the cell does not exist in the simulation.  Furthermore, the first existing cell above will be connected to the first existing cell below.  This type of cell is referred to as a ``vertical pass through'' cell.
 
 
 # --------------------- gwf disv vertices ---------------------

flopy/mf6/data/dfn/gwf-maw.dfn

@@ -51,7 +51,7 @@ longname save well flows to budget file
 description REPLACE save_flows {'{#1}': 'multi-aquifer well'}
 
 block options
-name stage_filerecord
+name head_filerecord
 type record head fileout headfile
 shape
 reader urword
@@ -68,7 +68,7 @@ in_record true
 reader urword
 tagged true
 optional false
-longname stage keyword
+longname head keyword
 description keyword to specify that record corresponds to head.
 
 block options
@@ -81,7 +81,7 @@ reader urword
 tagged false
 optional false
 longname file keyword
-description name of the binary output file to write stage information.
+description name of the binary output file to write head information.
 
 block options
 name budget_filerecord
@@ -292,7 +292,7 @@ tagged false
 in_record true
 reader urword
 longname well radius
-description radius for the multi-aquifer well.
+description radius for the multi-aquifer well. The program will terminate with an error if the radius is less than or equal to zero.
 
 block packagedata
 name bottom
@@ -302,7 +302,7 @@ tagged false
 in_record true
 reader urword
 longname well bottom
-description bottom elevation of the multi-aquifer well. The well bottom is reset to the cell bottom in the lowermost GWF cell connection in cases where the specified well bottom is above the bottom of this GWF cell.
+description bottom elevation of the multi-aquifer well. If CONDEQN is SPECIFIED, THIEM, SKIN, or COMPOSITE, BOTTOM is set to the cell bottom in the lowermost GWF cell connection in cases where the specified well bottom is above the bottom of this GWF cell. If CONDEQN is MEAN, BOTTOM is set to the lowermost GWF cell connection screen bottom in cases where the specified well bottom is above this value. The bottom elevation defines the lowest well head that will be simulated when the NEWTON UNDER\_RELAXATION option is specified in the GWF model name file. The bottom elevation is also used to calculate volumetric storage in the well.
 
 block packagedata
 name strt
@@ -312,7 +312,7 @@ tagged false
 in_record true
 reader urword
 longname starting head
-description starting head for the multi-aquifer well.
+description starting head for the multi-aquifer well. The program will terminate with an error if the starting head is less than the specified well bottom.
 
 block packagedata
 name condeqn
@@ -407,7 +407,7 @@ tagged false
 in_record true
 reader urword
 longname screen top
-description value that defines the top elevation of the screen for the multi-aquifer well connection. If the specified SCRN\_TOP is greater than the top of the GWF cell it is set equal to the top of the cell.  SCRN\_TOP can be any value if CONDEQN is SPECIFIED, THIEM, SKIN, or COMPOSITE and SCRN\_TOP is set to the top of the cell.
+description value that defines the top elevation of the screen for the multi-aquifer well connection. If CONDEQN is SPECIFIED, THIEM, SKIN, or COMPOSITE, SCRN\_TOP can be any value and is set to the top of the cell. If CONDEQN is MEAN, SCRN\_TOP is set to the multi-aquifer well connection cell top if the specified value is greater than the cell top. The program will terminate with an error if the screen top is less than the screen bottom.
 
 block connectiondata
 name scrn_bot
@@ -417,7 +417,7 @@ tagged false
 in_record true
 reader urword
 longname screen bottom
-description value that defines the bottom elevation of the screen for the multi-aquifer well connection. If the specified SCRN\_BOT is less than the bottom of the GWF cell it is set equal to the bottom of the cell.  SCRN\_BOT can be any value if CONDEQN is SPECIFIED, THIEM, SKIN, or COMPOSITE and SCRN\_BOT is set to the bottom of the cell.
+description value that defines the bottom elevation of the screen for the multi-aquifer well connection. If CONDEQN is SPECIFIED, THIEM, SKIN, or COMPOSITE, SCRN\_BOT can be any value is set to the bottom of the cell. If CONDEQN is MEAN, SCRN\_BOT is set to the multi-aquifer well connection cell bottom if the specified value is less than the cell bottom. The program will terminate with an error if the screen bottom is greater than the screen top.
 
 block connectiondata
 name hk_skin
@@ -437,7 +437,7 @@ tagged false
 in_record true
 reader urword
 longname skin radius
-description real value that defines the skin radius (filter pack radius) for the multi-aquifer well. RADIUS\_SKIN can be any value if CONDEQN is SPECIFIED or THIEM. Otherwise, RADIUS\_SKIN must be greater than RADIUS for the multi-aquifer well.
+description real value that defines the skin radius (filter pack radius) for the multi-aquifer well. RADIUS\_SKIN can be any value if CONDEQN is SPECIFIED or THIEM. If CONDEQN is SKIN, CUMULATIVE, or MEAN, the program will terminate with an error if  RADIUS\_SKIN is less than or equal to the RADIUS for the multi-aquifer well.
 
 
 # --------------------- gwf maw period ---------------------
@@ -563,7 +563,7 @@ in_record true
 reader urword
 time_series true
 longname well head
-description is the head in the multi-aquifer well. WELL\_HEAD is only applied to constant head (STATUS is CONSTANT) and inactive (STATUS is INACTIVE) multi-aquifer wells. 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.
+description is the head in the multi-aquifer well. WELL\_HEAD is only applied to constant head (STATUS is CONSTANT) and inactive (STATUS is INACTIVE) multi-aquifer wells. 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. The program will terminate with an error if WELL\_HEAD is less than the bottom of the well.
 
 block period
 name head_limit

flopy/mf6/data/dfn/gwf-sfr.dfn

@@ -397,7 +397,7 @@ tagged false
 in_record true
 reader urword
 longname number of connected reaches
-description integer value that defines the number of reaches connected to the reach.
+description integer value that defines the number of reaches connected to the reach.  If a value of zero is specified for NCON an entry for RNO is still required in the subsequent CONNECTIONDATA block.
 
 block packagedata
 name ustrf

flopy/mf6/data/dfn/gwt-adv.dfn

@@ -0,0 +1,11 @@
+# --------------------- gwt adv options ---------------------
+
+block options
+name scheme
+type string
+valid central upstream tvd
+reader urword
+optional true
+longname advective scheme
+description scheme used to solve the advection term.  Can be upstream, central, or TVD.
+