Appendix A — Commands

A.1 Overview

All TUFLOW CATCH commands, parameters and descriptions are listed below (TCC Commands). For an explanation of command colour coding and notation, see Commands and Parameters.

Commands in this appendix are documented as a command with an operator and input options (separated by |). For example, GIS Format == SHP | GPKG. Each appendix entry is comprised of the following components:

  • Command heading: command == parameter(s) or input option(s)

  • A summary block with the following information where applicable:

    • Status: whether the command is required, optional, conditional or legacy, along with a reason if applicable.
    • .tcc Block: the block of the TUFLOW CATCH Control (.tcc) file in which the command should be used.
    • Model Construction: links to the construction section in which the command is typically used.
    • Required Dependent Command(s): other commands that must be used alongside this command.
    • Related Command(s): other commands that are related to this command.

  • Description: A paragraph describing what the command does, and any important notes.

  • Parameter subsections or table: If the command has parameters, they will be listed either in individual subsetions or a table, depending on the complexity.

    The subsection or table will contain the following information:

    • Parameter: The parameter as reference in the command heading.
    • Units: the units for the parameter value.
    • Science: links to the science sections where the governing equations and background are described.
    • A description paragraph typically follows the summary block, providing context and guidance on how to set the parameter.

A.2 TCC Commands

Catch BC Output Folder == <folder>

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the location to which all TUFLOW CATCH intermediate files are written. These include TUFLOW FV boundary condition files and blocks, and summed flow and pollutant outputs. It is strongly recommended that this be set to the bc database folder within the TUFLOWCATCH directory, i.e.:

Catch BC Output Folder == ..\bc_dbase

It can be a relative or absolute path. This is not the location for TUFLOW HPC and TUFLOW FV results files.

Catch BC Output Interval Lateral == \(dT_{lat}\)

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the timestep (in simulation time seconds) at which lines within a lateral (element, QC) boundary condition file for TUFLOW FV (created from TUFLOW HPC predictions) are separated.

\(dT_{lat}\) - Lateral Boundary Timestep

Units: seconds (s)
Science: Section 4.5.1

The timestep at which lines within a lateral (element, QC) boundary condition file for TUFLOW FV (created from TUFLOW HPC predictions) are separated. This is not the timestep at which boundary data is written from memory to file.

Catch BC Output Interval Nodestring == \(dT_{ns}\)

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the timestep (in simulation time seconds) at which lines within a nodestring (Q) boundary condition file for TUFLOW FV (created from TUFLOW HPC predictions) are separated.

\(dT_{ns}\) - Nodestring Boundary Timestep

Units: seconds (s)
Science: Section 4.5.1

The timestep at which lines within a nodestring (Q) boundary condition file for TUFLOW FV (created from TUFLOW HPC predictions) are separated. This is not the timestep at which boundary data is written from memory to file.

Catchment BC Nodestring == <gis_nodestring_path>

Status: Required
.tcc Block: Receiving Model (TUFLOW FV)
Model Construction: Section 4.5.4

Used to set the path to the file containing nodestrings for catchment inflows (Q type) to be generated by TUFLOW CATCH. All other inflows will be type QC.

Recommended example:

Catchment BC Nodestring == ..\..\TUFLOW\model\gis\2d_ns_name_L.shp

Catchment Hydraulic Model == HPC | None

Status: Required
.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): End Catchment Pollutant Export Model

Used to define the start of a catchment hydraulic model block. This block contains the commands that control catchment simulation of surface (and optionally subsurface) hydrology and hydraulics, and is essentially the contents of a TUFLOW HPC *.tcf control file. It does not include any pollutant export commands. Set the argument to none if only receiving water modelling is to be undertaken through the TUFLOW CATCH control file. This command must be matched with a subsequent End Catchment Hydraulic Model command.

Catchment Pollutant Export Model == Mass Accumulation Release | None

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3
Required Dependent Command(s): End Catchment Pollutant Export Model

Used to define the start of a catchment pollutant export model block. This block contains the commands that control pollutant export. Set the argument to none if only hydrology is being simulated, as per TUFLOW CATCH’s Hydrology configuration. This command must be matched with a subsequent End Catchment Pollutant Export Model command.

Coefficients == \(R_j\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5.1.1
Required Dependent Command(s): Catchment Pollutant Export Model, Device, Read GIS Intervention

Used in a device block to set the coefficients associated with a constant equation based mass removal model. The same command can be used to set coefficients for other equation based models as appropriate.

\(R_j\) - Constant mass removal proportion

Units: dimensionless (-)
Science: Section 3.3.1.1.1

The constant proportion of mass of constituent \(j\) removed by a given intervention in a timestep. A value of 0.0 (1.0) indicates no (complete) mass removal. Must be non-negative and less than or equal to 1.0.

Constant <Pollutant-Name> == Float

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.1
Required Dependent Command(s): Catchment Pollutant Export Model

Used to set a named pollutant <pollutant-name> concentration to a constant value. The command argument is the value to be set. This value is applied equally to all boundaries and summary files where appropriate. An example might be the setting of salinity in catchment flows as 0.0 g/L.

CSV Write Frequency Day == \(dT_{csv}\)

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the timestep at which boundary condition data stored in memory is written to boundary condition files for TUFLOW FV (created from TUFLOW HPC predictions).

\(dT_{csv}\) - CSV Write Timestep

Units: days (d)
Science: Section 4.5.1

The timestep (in simulation time) at which boundary condition data in memory is written to boundary condition files for TUFLOW FV (created from TUFLOW HPC predictions). This is not the timestep separating individual lines in a boundary condition file.

Deposition Stress == \(\tau_{cd}\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3.2
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the maximum bed shear stress that allows for deposition to occur. This deposition represents a transfer from a pollutant’s wet to dry store. Deposition will not occur at shear stresses above this value. Applies only to shear stress pollutant export methods, e.g. Shear1. It is not used for (nor is it an argument of) accumulation washoff pollutant export models, e.g. Washoff1.

\(\tau_{cd}\) - Critical Shear Stress for Deposition

Units: newtons per square metre (N/m\(^2\))
Science: Section 3.2.3.2.2

The maximum bed shear stress at which deposition can occur from a pollutant’s wet to dry store. The rate at which this deposition occurs is then set by the specified settling velocity. Used only in shear stress pollutant export models. Set to a small (large) number for reduced (enhanced) pollutant settling. Evaluated on a cell by cell basis. Should be less than the corresponding critical shear stress for erosion.

Deposition Velocity == \(w_s\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the settling velocity of a pollutant. This settling represents a transfer from a pollutant’s wet to dry store. Settling occurs at all times in the accumulation washoff pollutant export model. Settling only occurs once bed shear stress drops below the user specified value in the shear stress pollutant export model.

\(w_s\) - Deposition Velocity

Units: metres per day (m/d)
Science: Section 3.2.3.2.2

The still water velocity at which a pollutant settles from the wet to dry store. Set to a small (large) number for reduced (enhanced) pollutant settling. Evaluated on a cell by cell basis.

Depth Threshold == \(d\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the minimum cell water depth at which pollutant export can occur. Applies to all pollutant export methods.

\(d\) - Water Depth Threshold

Units: metres (m)
Science: Section 3.2.3.1.2

The minimum cell water depth for which pollutant export is permitted for a given pollutant within a given material. Below this depth, no pollutant export occurs. Applies equally to all pollutant export models. Evaluated on a cell by cell basis.

Device == <device-name>

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5
Required Dependent Command(s): Catchment Pollutant Export Model, Read GIS Intervention, End Device

Used to initiate a device block.

End Catchment Hydraulic Model

.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to define the end of a catchment hydraulic model block. This block contains the commands that control catchment simulation of surface (and optionally subsurface) hydrology and hydraulics, and is essentially the contents of a TUFLOW HPC *.tcf control file. It does not include any pollutant export commands. This command must be matched with a preceding Catchment Hydraulic Model command.

End Catchment Pollutant Export Model

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3
Required Dependent Command(s): Catchment Pollutant Export Model

Used to define the end of a catchment pollutant export model block. This block contains the commands that control pollutant export. This command must be matched with a preceding Catchment Pollutant Export Model command.

End Device

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5
Required Dependent Command(s): Catchment Pollutant Export Model, Device

Used to terminate a device block.

End Material

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used to end application of a material by material block pollutant export properties. This command must be accompanied by a preceding Material command.

End Receiving Model

.tcc Block: Receiving Model (TUFLOW FV)
Model Construction: Section 4.5.4
Required Dependent Command(s): Receiving Model

Used to define the end of a receiving model block. This block contains the commands that control receiving simulation of hydrodynamics and other processes, and is essentially the contents of a TUFLOW FV *.fvc control file. This command must be matched with a preceding Receiving Model command.

End Time == <simulation_end_time>

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the simulation end date in the format declared by Time Format. It is strongly recommended that ISODATE (dd/mm/yyyy hh:mm:ss) be deployed rather than hours.

Example use in ISODATE format (Time Format == ISODATE):

Time Format == ISODATE              ! Set the time format to ISODATE
Start Time == 01/01/2020 00:00:00   ! Specify the simulation start time in isodate format
End Time == 01/01/2020 03:00:00     ! Specify the simulation end time in isodate format

Example use in hours (Time Format == Hours):

Time Format == Hours        ! Set the time format to Hours
Start Time == 0             ! Specify the simulation start time in hours
End Time == 3               ! Specify the simulation end time in hours

Eqn == Constant

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5.1.1
Required Dependent Command(s): Catchment Pollutant Export Model, Device, Read GIS Intervention

Used in a device block to set the mass removal equation. More equations may become available in future.

Erosion Rate == \(E_r\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3.2
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the erosion rate of a pollutant. This erosion represents a transfer from a pollutant’s dry to wet store. Erosion only occurs once bed shear stress increases above the user specified value. Erosion will not occur at shear stresses below this value. Applies only to shear stress pollutant export methods, e.g. Shear1. It is not used for accumulation washoff pollutant export models, e.g. Washoff1.

\(E_r\) - Erosion Rate

Units: grams per square metre per second (g/m\(^2\)/s)
Science: Section 3.2.3.2.1

The rate at which a pollutant is eroded from its dry store. Used only in shear stress pollutant export models. Set to a small (large) number for reduced (enhanced) pollutant erosion. Evaluated on a cell by cell basis.

Erosion Stress == \(\tau_{ce}\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3.2
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the minimum bed shear stress that allows for erosion to occur. This erosion represents a transfer from a pollutant’s dry to wet store. Erosion will not occur at shear stresses below this value. Applies only to shear stress pollutant export methods, e.g. Shear1. It is not used for accumulation washoff pollutant export models, e.g. Washoff1.

\(\tau_{ce}\) - Critical Shear Stress for Erosion

Units: newtons per square metre (N/m\(^2\))
Science: Section 3.2.3.2.1

The minimum bed shear stress at which erosion can occur from a pollutant’s dry to wet store. Used only in shear stress pollutant export models. Set to a large (small) number for reduced (enhanced) pollutant erosion. Evaluated on a cell by cell basis. Should be greater than the corresponding critical shear stress for deposition.

EXE == <TUFLOWFV_executable_path>

Status: Required
.tcc Block: Receiving Model (TUFLOW FV)
Model Construction: Section 4.5.2
Required Dependent Command(s): Receiving Model

Used to set the path to the TUFLOW FV executable. The full path, either relative or absolute, is required, including the name of the executable itself, with the .exe extension.

For example:

EXE == "C:\Program Files\TUFLOW\TUFLOW FV 2026.0.0\TUFLOWFV.exe"

EXE == <TUFLOW_executable_path>

Status: Required
.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to set the path to the TUFLOW executable. The full path, either relative or absolute, is required, including the name of the executable itself, with the .exe extension.

For example:

EXE == "C:\Program Files\TUFLOW\TUFLOW 2026.0.0\TUFLOW_iSP_w64.exe"

GIS Format == SHP | GPKG

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1
Related Command(s): Catchment Hydraulic Model, Receiving Model

Used to set the GIS format of the simulation. This command can be overwritten in the catchment hydraulic model or receiving model blocks if needed. TUFLOW FV does not support GPKG format.

GPKG Projection == <gpkg_file>

Status: Conditional - Required if GIS Format == GPKG
.tcc Block: Global Commands
Model Construction: Section 4.5.1
Related Command(s): Catchment Hydraulic Model

Used to set the path to the GPKG file containing the TUFLOW CATCH model projection. This command can be overwritten in the catchment hydraulic model block if needed. Only used if GIS Format is set to GPKG. TUFLOW FV does not support GPKG format.

Groundwater Boundary Threshold Layer == <layer-number>

.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to set the deepest soil layer from which flows and loads will be taken to develop TUFLOW FV boundary conditions.

Groundwater Default Catch BC == Free Outflow | Zero Depth

.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to set the default groundwater boundary condition applied along the catchment model boundary. ‘Free Outflow’ specifies a zero-gradient condition, allowing groundwater to exit the model domain without imposing artificial resistance. This prevents boundary induced flow constraints and better represents natural drainage where no defined head condition is required. ‘Zero Depth’ applies a fixed groundwater depth of zero at the boundary. This option replicates behaviour from earlier releases and may be used for backward compatibility or where a controlled groundwater boundary is desired. The ‘Free Outflow’ condition is the default from the 2025.2.0 release onwards. This change was introduced to avoid unintended restrictions to groundwater movement.

GW Z Flux Output Normalise == ON | OFF

.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 6.2

Used to set whether output groundwater fluxes (GW_QZ and GW_QZI) in discharges and volumes are normalised to a unit area or not. The default option is ON, which normalises the output groundwater fluxes to a unit area. It is recommended to leave this command as default (ON) as the non-normalised results are difficult to interpret correctly due to interpolation. Prior to the 2026.0.0 TUFLOW CATCH release, this command did not exist and groundwater fluxes in discharges and volumes were not normalised to a unit area (OFF option).

Hardware == GPU | CPU

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the simulation hardware. This command can be overwritten in the catchment hydraulic model or receiving model blocks if needed.

Infiltration <Pollutant-Name> == ON | OFF

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.4

Used to set whether a named pollutant <pollutant-name> is allowed to infiltrate into the subsurface from surface flows. The command argument is ON or OFF. An example might be setting infiltration of sediment to be OFF.

Limit == \(L_{acc}\) | \(L_{shr}\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set an accumulation (washoff model) or erosion (shear model) limit.

\(L_{acc}\) - Accumulation Limit

Units: kilograms per hectare (kg/ha)
Science: Section 3.2.3.1.1

The maximum dry store areal mass of a given pollutant allowed to accumulate within a given material. Used with the Washoff1 pollutant export model. Above this value, no further mass is added to a cell’s dry store. Must be a positive number.

\(L_{shr}\) - Erosion Limit

Units: kilograms per hectare (kg/ha)
Science: Section 3.2.3.2.1

The maximum erosion or deposition allowed within a material for a given pollutant. The number is specified only as a positive number, but is applied equally to erosion and deposition. For example, if a number of 100 is specified, and erosion is occurring in a given cell, then erosion will stop when the areal mass reaches -100 kg/ha. Equally, if deposition is occurring in the same cell, it will cease when the areal mass reaches 100 kg/ha. These areal masses can be converted to eroded depth or accretion height by assuming a bulk density and applying a conversion from hectares to square metres.

Log Folder == <folder>

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the location to which all log files are written. It is strongly recommended that this be set to the log folder within the TUFLOWCATCH directory, i.e.:

Log Folder == log

It can be a relative or absolute path.

Map Output Data Types == <data_types>

Status: Required
.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2

Used to specify the map output data types. The command argument catch is a keyword and should be added as an output along with all hydrologic outputs such as velocity, depth and water surface elevation (as shown in example below).

For example, the following arguments are recommended as the minimum output data types for a TUFLOW CATCH simulation:

Map Output Data Types == V h d catch

Material == ALL | <material_id_1, material_id_2, …, material_id_10>

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3
Required Dependent Command(s): End Material

Used to apply a material by material pollutant export properties. Up to 10 comma separated materials can be included in one material block command. Alternatively, the keyword all can be specified and this will instruct TUFLOW CATCH to apply the properties in that corresponding material block to all TUFLOW HPC cells. This is a useful way to set the most commonly occurring conditions for all pollutants across the domain, and acts as a default condition. Subsequent Material block declarations for subsets of the entire domain (e.g. for one or more materials) will progressively spatially overwrite this global declaration. This command must be followed by an End Material command to finalise the block.

Method == Washoff1 | Shear1

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the pollutant export model.

For details on each pollutant export model:

Method == Eqn | Table

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5
Required Dependent Command(s): Catchment Pollutant Export Model, Device, Read GIS Intervention

Used in a device block to set the mass removal method (i.e. adopted model). More methods may become available in future.

Output Directory == <folder>

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the location to which all TUFLOW HPC and TUFLOW FV results are written. It is strongly recommended that this be set to the results folder within the TUFLOWCATCH directory, but can be set elsewhere if file size constraints apply. For example:

Output Directory == ..\results

It can be a relative or absolute path. This is not the location for the TUFLOW CATCH intermediate files.

Path == <intervention_table_path>

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5.2
Required Dependent Command(s): Catchment Pollutant Export Model, Device, Read GIS Intervention, Method

Used in a device block to set the mass removal table for the Method == Table method.

Pollutant == <pollutant_name_1, pollutant_name_2, … >

.tcc Block: Receiving Model (TUFLOW FV)
Model Construction: Section 4.5.2
Required Dependent Command(s): Receiving Model

Used to set the names of pollutants to be simulated in the pollutant export model. Only used when TUFLOW CATCH is executed in Pollutant export configuration. Any pollutant names can be used in this command, and they do not need to be those that are generated by TUFLOW FV.

Preserve Catchment Inflows == ON | OFF

.tcc Block: Receiving Model (TUFLOW FV)
Model Construction: Section 4.5.2
Required Dependent Command(s): Receiving Model

Used to prevent TUFLOW CATCH from overwriting a previously created (non-blank) TUFLOW FV boundary condition bc block file. Used when preliminary TUFLOW FV boundary condition inflows have been generated by TUFLOW CATCH to support initial TUFLOW FV calibration. Avoids the need to continually rerun TUFLOW HPC within TUFLOW CATCH when undertaking only a TUFLOW FV calibration.

Rain Threshold == \(R_r\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3.1
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the minimum rainrate threshold at which a pollutant is released from its dry store. Pollutant export is suppressed below this rate. Applies only to accumulation pollutant export methods, e.g. Washoff1. It is not used for erosion pollutant export models, e.g. Shear1.

\(R_r\) - Rainrate Threshold

Units: millimetres per hour (mm/hr)
Science: Section 3.2.3.1.2

The minimum instantaneous cell rain rate above which pollutant is exported from its dry store. Used only in accumulation pollutant export models. Set to a large (small) number for reduced (enhanced) pollutant washoff. Evaluated on a cell by cell basis.

Rate == \(R_a\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3.1
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to set the rate at which a pollutant accumulates to its dry store. Applies only to accumulation pollutant export methods, e.g. Washoff1. It is not used for erosion pollutant export models, e.g. Shear1.

\(R_a\) - Dry Store Accumulation Rate

Units: kilograms per hectare per year (kg/ha/yr)
Science: Section 3.2.3.1.1

The rate at which a pollutant accumulates mass to its dry store. Used only in accumulation pollutant export models. Set to zero to suppress pollutant export or a large value to rapidly populate pollutant dry stores. This might be useful in setting initial conditions.

Read GIS Intervention == <gis_interventions_file>

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5
Required Dependent Command(s): Catchment Pollutant Export Model

Used to set the path to any number of polylines that define the locations of TUFLOW CATCH interventions. This is only used in the TUFLOW CATCH Pollutant export or Integrated configurations. All TUFLOW HPC cells intersecting each polyline are treated as intervention cells. TUFLOW CATCH writes a summary intervention file of removed and passed flows and loads for each intervention. This data can be used to compare across pollutant export scenarios, for example, or in catchment wide mass balance analyses.

Recommended example:

Read GIS Intervention == ..\..\TUFLOW\model\gis\2d_im_name_L.shp

Receiving Model == TUFLOWFV | None

.tcc Block: Receiving Model (TUFLOW FV)
Model Construction: Section 4.5.4
Required Dependent Command(s): End Receiving Model

Used to define the start of a receiving model block. This block contains the commands that control receiving simulation of hydrodynamics, advection dispersion, water quality and other optional processes, and is essentially the contents of a TUFLOW FV *.fvc control file. Set the argument to none if only catchment hydraulic water modelling is to be undertaken through the TUFLOW CATCH control file. TUFLOW CATCH will then not invoke TUFLOW FV. This ‘none’ option is required for the Pollutant export configuration. This command must be matched with a subsequent End Receiving Model command.

Receiving Polygon == <gis_polygon_file>

Status: Conditional - Required if Receiving Model == None
.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to set the path to a polygon that delineates the downstream receiving waterway extents of a TUFLOW CATCH simulation. This is only used in the TUFLOW CATCH Pollutant export configuration. All TUFLOW HPC cells and boundary conditions within this polygon are excluded from the TUFLOW HPC simulation. TUFLOW CATCH writes flow and pollutant export summary and timeseries files that contain aggregated flows and loads entering the nominated polygon. These data can be used to compare across pollutant export scenarios, for example, without the need to build a TUFLOW FV model or mesh.

Recommended example:

Receiving Polygon == ..\..\TUFLOW\model\gis\2d_rp_name_P.shp

Runs Directory == <folder>

.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to set the path from which TUFLOW runs are to be automatically controlled by TUFLOW CATCH. This is the directory to which TUFLOW CATCH writes interim *.tcf and similar files, but the user does not need to interrogate or interact with these files - this command simply tells TUFLOW CATCH where the master TUFLOW control files are to be housed. It is strongly recommended to set this directory to the runs folder within the TUFLOW directory, i.e.:

Runs Directory == ..\..\TUFLOW\runs

It is not recommended that users interact with any files in this directory, although users will create and modify content in all other directories under TUFLOW if TUFLOW HPC simulations are invoked. This interaction will occur through the TUFLOW CATCH *.tcc control file.

Runs Directory == <folder>

.tcc Block: Receiving Model (TUFLOW FV)
Model Construction: Section 4.5.2
Required Dependent Command(s): Receiving Model

Used to set the path from which TUFLOW FV runs are to be automatically controlled by TUFLOW CATCH. This is the directory to which TUFLOW CATCH writes interim *.fvc and similar files, but the user does not need to interrogate or interact with these files - this command simply tells TUFLOW CATCH where the master TUFLOW FV control files are to be housed. It is strongly recommended to set this directory to the runs folder within the TUFLOWFV directory, i.e.:

Runs Directory == ..\..\TUFLOWFV\runs

It is not recommended that users interact with any files in this directory, although users will create and modify content in all other directories under TUFLOWFV if TUFLOW FV simulations are invoked. This interaction will occur through the TUFLOW CATCH *.tcc control file.

SHP Projection == <projection_file_or_prj>

Status: Conditional - Required in Receiving Model block. Required in General or Catchment Hydraulic Model blocks if GIS Format == SHP
.tcc Block: Global Commands
Model Construction: Section 4.5.1
Related Command(s): Catchment Hydraulic Model, Receiving Model

Used to set the path to the SHP file containing the TUFLOW CATCH model projection. Can be set globally and then overwritten as needed within Catchment Hydraulic Model or Receiving Model blocks.

Recommended example:

SHP Projection == ..\..\TUFLOW\model\gis\Projection.prj

Start Time == <simulation_start_time>

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the simulation start date in the format declared by Time Format. It is strongly recommended that ISODATE (dd/mm/yyyy hh:mm:ss) be deployed rather than hours.

Example use in ISODATE format (Time Format == ISODATE):

Time Format == ISODATE              ! Set the time format to ISODATE
Start Time == 01/01/2020 00:00:00   ! Specify the simulation start time in isodate format
End Time == 01/01/2020 03:00:00     ! Specify the simulation end time in isodate format

Example use in hours (Time Format == Hours):

Time Format == Hours        ! Set the time format to Hours
Start Time == 0             ! Specify the simulation start time in hours
End Time == 3               ! Specify the simulation end time in hours

Time Constant == \(T_c\)

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.3.1
Required Dependent Command(s): Catchment Pollutant Export Model, Material

Used in a material block to control the rate at which a pollutant is released from its dry store. Applies only to accumulation pollutant export methods, e.g. Washoff1. It is not used for erosion pollutant export models, e.g. Shear1.

\(T_c\) - Washoff Time Constant

Units: seconds (s)
Science: Section 3.2.3.1.2

A time constant that controls the rate at which a pollutant is washed off (out of its dry store) when both minimum cell water depth and rainfall conditions are met. Used only in accumulation pollutant export models. Set to a large (small) number for slow (rapid) pollutant dry store release.

Time Format == ISODATE | Hours

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the simulation date format. It is strongly recommended that ISODATE (dd/mm/yyyy hh:mm:ss) be deployed rather than hours.

Time Format == TUFLOWFV

.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to set the time format of output results. Setting to TUFLOWFV is strongly recommended, and use of hours should be avoided. Should be used in conjunction with Zero Date so that TUFLOW HPC boundaries can be specified in hours (TUFLOW HPC cannot accept ISODATE format in its boundary files at time of writing).

Time-Series <Pollutant-Name> == <BC-Database-Name>

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.2
Required Dependent Command(s): Catchment Pollutant Export Model

Used to apply a named pollutant pollutant-name concentration to a timeseries. The command argument is the name of the timeseries as specified by the user in the TUFLOW HPC boundary database. TUFLOW CATCH will interpolate between the specified timeseries and required frequency of writing outputs as needed. An example might be setting water temperature to be a timeseries that reflects seasonality.

Units == {MGL} | GL | MICGL | CFU100ML

.tcc Block: Catchment Pollutant Export Model
Model Construction: Section 4.5.3.5.3
Required Dependent Command(s): Catchment Pollutant Export Model

Used to set the units of a simulated constituent.

Write Check Files == <folder>

Status: Required
.tcc Block: Global Commands
Model Construction: Section 4.5.1

Used to set the location to which all check files are written. It is strongly recommended that this be set to the check folder within the TUFLOWCATCH directory, i.e.:

Write Check Files == ..\check

It can be a relative or absolute path.

Zero Date == <time_in_TUFLOWFV_ISODATE>

.tcc Block: Catchment Hydraulic Model (HPC)
Model Construction: Section 4.5.2
Required Dependent Command(s): Catchment Hydraulic Model

Used to set the date in TUFLOWFV ISODATE format (dd/mm/yyyy hh:mm) that corresponds to zero hours in TUFLOW HPC boundary condition files. Seconds is not required in the date specification.