Data Sets Required by MODFLOW

Table 8. Data Sets required by MODFLOW

Data Set	Description	Package	Variable	When used
Active	Specifies whether a cell is active or not.	BAS	IBOUND	Always
Modflow_Initial_Head	Initial head used in the model	BAS	STRT	Always
Kx	Hydraulic conductivity along rows.	LPF BCF6 UPW	HK HY HK	When the LPF, BCF6, or UPW package is active and no HK parameters are defined
Horizontal_Anisotropy	The ratio of hydraulic conductivity along columns to hydraulic conductivity along rows, where Kx is the hydraulic conductivity along rows. Thus, the hydraulic conductivity along columns is the product of the values in Kx and Horizontal_Anisotropy.	LPF UPW	HANI HANI	When the LPF or UPW package is active, no HANI parameters are defined.
Kz	The vertical hydraulic conductivity. The default formula for Confining_Bed_Kz refers to Kz so that all vertical hydraulic conductivities can be set through Kz.	LPF BCF6 UPW	VKA Vcont VKA	When the LPF, BCF6, or UPW package is active and no VK or VANI parameters are defined and the Method of specifying vertical hydraulic conductivity is vertical hydraulic conductivity.
Confining_Bed_Kz	The vertical hydraulic conductivity of a Quasi-three-dimensional confining bed.	LPF BCF6 UPW	VKCB Vcont VKCB	When the LPF, BCF6, or UPW package is active and no VKCB parameters are defined and there is at least one nonsimulated layer.
Vertical_Anisotropy	The ratio of horizontal to vertical hydraulic conductivity	LPF UPW	VKA VKA	When the LPF or UPW package is active and no VK or VANI parameters are defined and the Method of specifying vertical hydraulic conductivity is the ratio of horizontal to vertical hydraulic conductivity.
Specific_Storage	Specific storage	LPF BCF6 UPW	Ss Sf1 Ss	When the LPF, BCF6, or UPW package is active and the model contains at least one transient stress period.
Specific_Yield	Specific yield	LPF BCF6 UPW	Sy Sf1, Sf2 Sy	When the LPF, BCF6, or UPW package is active, the model contains at least one transient stress period and there is at least one convertible layer and no specific yield parameters are defined.
Wet_Dry_Threshold	The wetting threshold. It is used in the formula for WetDry.	LPF BCF6	WETDRY WETDRY	Never used directly.
Wet_Dry_Flag	A flag to indicate which neighboring cells can cause a cell to become wet. It is used in the formula for WetDry. •If Wet_Dry_Flag > 0, any cell adjacent to the dry cell, except the cell above the dry cell, can cause the dry cell to convert to an active cell. •If Wet_Dry_Flag = 0, the dry cell can not convert to an active cell. •If Wet_Dry_Flag < 0, only the cell below the dry cell can cause the dry cell to convert to an active cell. The Wet_Dry_Flag data set is restricted to values between -1 and 1.	LPF BCF6	WETDRY WETDRY	Never used directly.
WetDry	A combination of the wetting threshold and a flag to indicate which neighboring cells can cause a cell to become wet.	LPF BCF6	WETDRY WETDRY	When the LPF or BCF6 package is active, the Layer type for at least one layer is convertible, and Wetting is active.
Confined_Storage_Coefficient	The confined storage coefficient is the specific storage times the layer thickness	BCF6	Sf1	When the BCF6 package is active, the model has at least one transient stress period, and a Confined or a Limited convertible layer is present.
Transmissivity	The transmissivity is the horizontal hydraulic conductivity times the layer thickness.	BCF6	Tran	When a Confined or a Limited convertible layer is present.
Vertical_Conductance	The vertical conductance is the vertical hydraulic conductivity divided by the thickness from the center of one layer to the center of the underlying layer. See page 5-7 of the MODFLOW-2005 documentation for more details.	BCF6	Vcont	Used in all but the bottom layer.
Reservoir_Layer	The model layer to which the reservoir is connected.	RES	IRESL	When the Reservoir package is used and the user chooses a Specified layer.
Reservoir_Elevation	Land-surface elevation for all reservoirs	RES	BRES	When the Reservoir package is used.
Reservoir_Hydraulic_Conductivity	Vertical hydraulic conductivity of the reservoir bed for all reservoirs	RES	HCres	When the Reservoir package is used.
Reservoir_Bed_Thickness	Thickness of reservoir-bed sediments for all reservoirs	RES	Rbthck	When the Reservoir package is used.
Lake_ID	The identification number of the lake occupying the grid cell	LAK	LKARR	When the Lake package is used.
Lakebed_Leakance	The lakebed leakance that will be assigned to lake/aquifer interfaces that occur in the corresponding grid cell. Note lakebed leakance is used differently in the BCF and LPF packages.	LAK	BDLKNC	When the Lake package is used.
Land_Surface	The elevation of the land surface.	UZF and FMP	used to assign IUZFBND and GSURF	When either the Unsaturated-Zone Flow package or the Farm Process is used.
UZF_Layer	Used to define the aerial extent of the active model in which recharge and discharge will be simulated. A value of 0 indicates recharge and discharge will not be simulated. If NUZTOP ≥ 2, the value of IUZFBND indicates the layer whose top is the land surface. If NUZTOP = 2, the value of IUZFBND indicates the layer where recharge and discharge occurs.	UZF	IUZFBND	When the Unsaturated-Zone Flow package is used.
Discharge_Routing	Used to define the stream segments within the Streamflow-Routing (SFR2) Package or lake numbers in the Lake (LAK3) Package that overland runoff from excess infiltration and groundwater discharge to land surface will be added. A positive integer value identifies the stream segment and a negative integer value identifies the lake number.	UZF	IRUNBND	When the Unsaturated-Zone Flow package is used and discharge is routed to streams and lakes and either the Lake or Streamflow Routing package is active.
Maximum_Unsaturated_Vertical_K	The saturated vertical hydraulic conductivity of the unsaturated zone (L/t).	UZF	VKS	When the Unsaturated-Zone Flow package is used and the user chooses to specify vertical hydraulic conductivity in the unsaturated zone separately from that in the saturated zone or else neither the LPF nor UPW package is used.
Brooks_Corey_Epsilon	The Brooks-Corey epsilon of the unsaturated zone. Epsilon is used in the relation of water content to hydraulic conductivity (Brooks and Corey, 1966).	UZF	EPS	When the Unsaturated-Zone Flow package is used.
Saturated_Water_Content	The saturated water content of the unsaturated zone in units of volume of water to total volume (L3/L3).	UZF	THTS	When the Unsaturated-Zone Flow package is used.
Initial_Unsaturated_Water_Content	The initial water content for each vertical column of cells in units of volume of water at start of simulation to total volume (L3/L3).	UZF	THTI	When the Unsaturated-Zone Flow package is used and all the stress periods are transient and the user chooses to specify the initial water content in the unsaturated zone.
Residual_Water_Content	The residual water content for each vertical column of cells in units of volume of water to total volume (L3L-3)	UZF	THTR	When the Unsaturated-Zone Flow package is used and the user chooses to specify the residaul water content in the unsaturated zone.
UzfGage_1_and_2	A flag for the type of expanded listing desired in the output file. See UZF: Unsaturated-Zone Flow Package Pane	UZF	IUZOPT	When the Unsaturated-Zone Flow package is used.
UZF_Gage3	A flag for the type of expanded listing desired in the output file. See UZF: Unsaturated-Zone Flow Package Pane	UZF	IUZOPT	When the Unsaturated-Zone Flow package is used.
Uzf_Surficial_Hydraulic_Conductivity	Hydraulic conductivity of the surface (LT-1). SURFK is used for calculating the rejected infiltration and/or surface leakage.	UZF	SURFK	When the Unsaturated-Zone Flow package is used and the SPECIFYSURFK option is selected
HUF_Reference_Surface	the elevation of the reference surface to be used to calculate the depth	HUF2 (KDEP)	RS	When the HUF package is selected and one or more KDEP parameters is defined and the user chooses to use a reference surface different from the top of the model.
HUF_Kx	This data set is used to display the value of the hydraulic conductivity in the X direction that would be calculated by the HUF package.	HUF2		never used directly.
HUF_Ky	This data set is used to display the value of the hydraulic conductivity in the Y direction that would be calculated by the HUF package.	HUF2		never used directly.
HUF_Interlayer_Kz	This data set is used to display the value of the hydraulic conductivity in the Z direction between cell centers that would be calculated by the HUF package.	HUF2		never used directly.
HUF_SS	This data set is used to display the value of the specific storage that would be calculated by the HUF package.	HUF2		never used directly.
HUF_Average_SY	This data set is used to display the value of the average specific yield for a cell that would be calculated by the HUF package.	HUF2		never used directly.
HUF_SY	This data set is used to display the value of the specific storage that would be calculated by the HUF package.	HUF2		never used directly.
HUF_SYTP	This data set is used to display the value of SYTP (storage coefficient for the top active cell at each row, column location) that would be calculated by the HUF package.	HUF2		never used directly.
Geostatic_Stress	geostatic stress above model layer 1	SWT	GL0	When the SWT package is selected.
Specific_Gravity_Unsaturated	specific gravity of moist or unsaturated sediments	SWT	SGM	When the SWT package is selected.
Specific_Gravity_Saturated	specific gravity of saturated sediments	SWT	SGS	When the SWT package is selected.
Initial_Preconsolidation_Stress_Offset	The offset from initial effective stress to initial preconsolidation stress at the bottom of the model layer in units of height of a column of water	SWT	PCSOFF	When the SWT package is selected and the user chooses to specify the initial preconsolidation stress as an offset from the initial stress.
Initial_Preconsolidation_Stress	The initial preconsolidation stress, in units of height of a column of water, at the bottom of the model layer	SWT	PCS	When the SWT package is selected and the user chooses to specify the initial preconsolidation stress directly.
MODFLOW_Specified_Head	Values in this data set are set to true automatically in any specified head cell. It can not be manually set by the user. It is used in the formula for UZF_Layer	BAS	IBOUND	never used directly.
PipeDiameter	This data set can not be specified directly by the user or used in formulas.	CFP	DIAMETER	When CFP is used and individual conduits are simulated.
Tortuosity	This data set is used for visualization. It can not be specified directly by the user or used in formulas because it does not have a value defined in every cell.	CFP	TORTUOSITY	When CFP is used and individual conduits are simulated.
RoughnessHeight	This data set is used for visualization. It can not be specified directly by the user or used in formulas because it does not have a value defined in every cell.	CFP	RHEIGHT	When CFP is used and individual conduits are simulated.
LowerCriticalR	This data set is used for visualization. It can not be specified directly by the user or used in formulas because it does not have a value defined in every cell.	CFP	LCRITREY_P	When CFP is used and individual conduits are simulated.
UpperCriticalR	This data set is used for visualization. It can not be specified directly by the user or used in formulas because it does not have a value defined in every cell.	CFP	TCRITREY_P	When CFP is used and individual conduits are simulated.
PipeConductanceOrPermeabilty	This data set is used for visualization. It can not be specified directly by the user or used in formulas because it does not have a value defined in every cell.	CFP	K_EXCHANGE	When CFP is used and individual conduits are simulated.
CfpNodeElevation	This data set is used for visualization. It can not be specified directly by the user or used in formulas because it does not have a value defined in every cell.	CFP	GEOHEIGHT	When CFP is used and individual conduits are simulated.
CfpFixedHeads	This data set is used for visualization. It can not be specified directly by the user or used in formulas because it does not have a value defined in every cell.	CFP	N_HEAD	When CFP is used and individual conduits are simulated.
Active_Surface_Elevation[i]	The Active_Surface_Elevation[i] is the initial elevation of a ZETA surface in the SWI2 package.	SWI2	ZETA	When SWI2 is used
EffectivePorosity	Effective porosity	SWI2	SSZ	When SWI2 is used
FluidSourceDensityZone	FluidSourceDensityZone identifies the zone in the SWI2 package that is the source of sink of fluid.	SWI2	ISOURCE	When SWI2 is used
SWI_Observation_Name	Any cell with a value other than "" will be an observation cell in the SWI2 package.	SWI2	OBSNAM	When SWI2 is used and ISWIOBS is not zero.
SWR_Reach_Group_Number	In the SWR process, multiple reaches can be part of a reach group. This data set is used for displaying reach group numbers.	SWR	IRGNUM	When SWR is used.
SWR_Reach_Length	This data set is used for displaying the length or a reach in SWR.	SWR	RLEN	When SWR is used.
SWR_Reach_Number	This data set is used for displaying the reach number for each reach in SWR.	SWR	IRCH4A	When SWR is used.
SWR_Routing_Type	This data set is used for displaying the routing type of each reach in SWR. •IROUTETYPE = 1, Level-pool reservoir routing. •IROUTETYPE = 2, Tilted-pool reservoir routing. •IROUTETYPE = 3, Diffusive-wave approximation.	SWR	IROUTETYPE	When SWR is used.
Soil_ID	Specifies the spatial distribution of soils.	FMP	SID	When FMP is used.
Cell_Type	Specifies how cell thickness is calculated. •0: constant cell thickness •>0: calculated cell thickness •<0: constant or calculated cell thickness depending on THICKSTRT option	NPF	icelltype	MODFLOW 6 models
IDOMAIN	Specifies whether a call is active, inactive, or vertical pass through •1 = Active cells •0 = Inactive cells •-1 = Vertical pass-through cells	DIS, DISV	IDOMAIN	MODFLOW 6 models
Convertible	•0: confined •>0: convertible	STO	iconvert	Transient MODFLOW 6 models
XT3D_Angle_1	A rotation angle of the hydraulic conductivity tensor in degrees. ANGLE1 rotates the ellipsoid about its K33 axis (within the x - y plane).	MODFLOW 6 NPF	angle1	MODFLOW 6 models
XT3D_Angle_2	ANGLE2 rotates the ellipsoid about its K22 axis (out of the x - y plane).	MODFLOW 6 NPF	angle2	MODFLOW 6 models
XT3D_Angle_3	ANGLE3 rotates the ellipsoid about its K11 axis.	MODFLOW 6 NPF	angle3	MODFLOW 6 models
SFR6_ReachLength	the reach length	MODFLOW 6 SRF	rlen	MODFLOW 6 models in which the SFR package is used
SFR6_ReachWidth	the reach width	MODFLOW 6 SRF	rwid	MODFLOW 6 models in which the SFR package is used
SFR6_Gradient	the stream gradient (slope) across the reach	MODFLOW 6 SRF	rgrd	MODFLOW 6 models in which the SFR package is used
SFR6_StreambedTop	the top elevation of the reach streambed	MODFLOW 6 SRF	rtp	MODFLOW 6 models in which the SFR package is used
SFR6_StreambedThickness	the thickness of the reach streambed	MODFLOW 6 SRF	rbth	MODFLOW 6 models in which the SFR package is used
SFR6_HydraulicConductivity	the hydraulic conductivity of the reach streambed	MODFLOW 6 SRF	rhk	MODFLOW 6 models in which the SFR package is used
MAW_Radius	radius for the multi-aquifer well.	MODFLOW 6 MAW	radius	MODFLOW 6 models in which the MAW package is used
MAW_Bottom	bottom elevation of the multi-aquifer well	MODFLOW 6 MAW	bottom	MODFLOW 6 models in which the MAW package is used
MAW_Initial_Head	starting head for the multi-aquifer well	MODFLOW 6 MAW	strt	MODFLOW 6 models in which the MAW package is used
MAW_Screen_Top	the top elevation of the screen for the multi-aquifer well connection	MODFLOW 6 MAW	scrn_top	MODFLOW 6 models in which the MAW package is used
MAW_Screen_Bottom	the bottom elevation of the screen for the multi-aquifer well connection	MODFLOW 6 MAW	scrn_bot	MODFLOW 6 models in which the MAW package is used
MAW_Skin_K	the skin (filter pack) hydraulic conductivity	MODFLOW 6 MAW	hk_skin	MODFLOW 6 models in which the MAW package is used
MAW_Skin_Radius	skin radius (filter pack radius) for the multi-aquifer well	MODFLOW 6 MAW	radius_skin	MODFLOW 6 models in which the MAW package is used
Lake_Bed_Leakance	the bed leakance for the lake-GWF connection	MODFLOW 6 LAK	bedleak	MODFLOW 6 models in which the Lake package is used
Lake_Bed_Thickness	Only used for display purposes	MODFLOW 6 LAK		MODFLOW 6 models in which the Lake package is used
KLake_Bottom_Elevation	the bottom elevation for a HORIZONTAL lake-GWF connection	MODFLOW 6 LAK	belev	MODFLOW 6 models in which the Lake package is used
KLake_Top_Elevation	the top elevation for a HORIZONTAL lake-GWF	MODFLOW 6 LAK	telev	MODFLOW 6 models in which the Lake package is used
KLake_Connection_Length	the distance between the connected GWF CELLID node and the lake for a HORIZONTAL, EMBEDDEDH, or EMBEDDEDV lake-GWF connection	MODFLOW 6 LAK	connlen	MODFLOW 6 models in which the Lake package is used
KLake_Connection_Width	the connection face width for a HORIZONTAL lake-GWF connection.	MODFLOW 6 LAK	connwidth	MODFLOW 6 models in which the Lake package is used
UZF6_Brooks_Corey_Epsilon	the epsilon exponent of the UZF cell	MODFLOW 6 UZF	eps	MODFLOW 6 models in which the UZF package is used
UZF6_Initial_Unsaturated_Water_Content	the initial water content of the UZF cell.	MODFLOW 6 UZF	thti	MODFLOW 6 models in which the UZF package is used
UZF6_Residual_Water_Content	the residual (irreducible) water content of the UZF cell.	MODFLOW 6 UZF	thtr	MODFLOW 6 models in which the UZF package is used
UZF6_Saturated_Water_Content	the saturated water content of the UZF cell.	MODFLOW 6 UZF	thts	MODFLOW 6 models in which the UZF package is used
UZF6_Surface_Depression_Depth	the surface depression depth of the UZF cell.	MODFLOW 6 UZF	surfdep	MODFLOW 6 models in which the UZF package is used
UZF6_Vertical_Saturated_K	the vertical saturated hydraulic conductivity of the UZF cell.	MODFLOW 6 UZF	vks	MODFLOW 6 models in which the UZF package is used