The steady UZF properties are three dimensional data and can be assigned to all cells in the model.

Surface depression depth (surfdep): When the water table is above the top of a cell at the ground surface, infiltration is gradually reduced to zero until the water table rises above the tops of any surface depressions on the ground surface.

Saturated Kz (vks): The unsaturated vertical hydraulic conductivity (Kunsat) is related to the saturated  vertical hydraulic conductivity (Ksat) through the Brooks Corey equation. Kunsat = Ksat [(θ - θresid) / (θsat - θresid)]ε

Residual water content (thtr) The residual water content is θresid in the Brooks Corey equation.

Saturated water content (thts) The saturated water content is θrsat in the Brooks Corey equation.

Initial water content (thti) The initial water content of the UZF cell.

Brooks Corey epsilon (eps) The Brooks Corey epsilon is ε in the Brooks Corey equation.

Starting time and Ending time are explained in the help for the MODFLOW Features tab.

The time varying properties are two dimensional data assigned to the top of the model.

Infiltration (finf) is the applied infiltration rate (L/T). If the applied infiltration rate is larger than the vertical hydraulic conductivity, the actual infiltration will be reduced to the vertical hydraulic conductivity. Any remaining potential infiltration will be available to the MVR package as rejected infiltration.

UZF Multiplier is only used if it has been activated in the UZF6: Unsaturated-Zone Flow Package for MODFLOW 6. If UZF Multiplier is specified, the cell are of the UZF cell is multiplied by the UZF Multiplier value.

Potential ET (pet) is the potential evapotranspiration rate of the UZF cell and specified groundwater flow (GWF) cell. Evapotranspiration is first removed from the unsaturated zone and any remaining potential evapotranspiration is applied to the saturated zone. If the UZF cell overlies another UZF cell, then residual potential evapotranspiration not satisfied in the UZF cell is applied to the underlying UZF and GWF cells. PET is always specified but is only used if evapotranspiration is specified in the UZF 6 OPTIONS block.

Extinction depth (extdp) is the evapotranspiration extinction depth of the UZF cell. If the UZF cell overlies another UZF cell and EXTDP extends below the GWF cell bottom then remaining potential evapotranspiration is applied to the underlying UZF and GWF cells.  EXTDP is always specified but is only used if evapotranspiration is specified in the UZF 6 OPTIONS block.

Extinction water content (extwc) When the water content is at or below the extinction water content, no evapotranspiration will be simulated for the cell.  EXTWC is always specified but is only used if evapotranspiration is specified in the UZF 6 OPTIONS block.

Air entry potential (ha) is the air entry potential (head) of the UZF cell. HA is always specified, but is only used if evapotranspiration is simulated and the  UNSAT_ETAE option is specified in the UZF 6 OPTIONS block.

Root potential (hroot) is the root potential (head) of the UZF cell. HROOT is always specified, but is only used if evapotranspiration is simulated and  theUNSAT_ETAE is specified in the UZF 6 OPTIONS block.

Root activity (rootact) is the root activity function of the UZF cell. ROOTACT is the length of roots in a given volume of soil divided by that volume. Values range from 0 to about 3 cm-2, depending on the plant community and its stage of development. ROOTACT is always specified, but is only used if evapotranspiration is simulated and UNSAT_ETAE is specified in the OPTIONS block.

Auxiliary Variables If the Groundwater Transport process in MODFLOW 6 is active, auxiliary variables will be included. They represent the concentration of flow into the groundwater from the boundary. Flow out of the groundwater will be at the concentration in the cell containing the boundary.

The GWT tab is used for specifying data for the UZT package in groundwater transport. This tab is only visible if groundwater transport is active.

The left hand side has a list of the chemical species used in the model. For each chemical species, the user specifies the initial concentration and transient data for the species.

STATUS can be ACTIVE, INACTIVE, or CONSTANT. By default, STATUS is ACTIVE, which means that concentration will be calculated for the UZF cell. If a UZF cell is inactive, then there will be no solute mass fluxes into or out of the UZF cell and the inactive value will be written for the UZF cell concentration. If a UZF cell is constant,then the concentration for the UZF cell will be fixed at the user specified value.

Specified Concentration is the concentration for the unsaturated zone flow cell. The specified CONCENTRATION is only applied if the unsaturated zone flow cell is a constant concentration cell.

Infiltration Concentration defines the infiltration solute concentration (ML-3) for the UZF cell.

Evapotranspiration Concentration defines the concentration of unsaturated zone evapotranspiration water (ML-3) for the UZF cell. If this concentration value is larger than the simulated concentration in the UZF cell, then the unsaturated zone ET water will be removed at the same concentration as the UZF cell.