Appendix B ECF Commands

The TUFLOW ESTRY Control File (.ecf) includes commands and data inputs to build the 1D ESTRY domain, it is read into the .tcf using the ESTRY Control File command. For more information on the .ecf, see Section 4.2.5. Building the 1D domain is discussed in Chapter 5. The available ECF commands are listed below and are detailed in Table B.1.

Arch Bridge Minimum Blockage (%)
BC Database
BC Event Name
BC Event Text
Bridge Flow
Bridge Zero Coefficients
Conveyance Calculation
Create Nodes
CSV Format
CSV Maximum Number Columns
CSV Time
Culvert Critical H/D
Culvert Flow
Culvert Zero Coefficients
Depth Discharge Database
Depth Limit Factor
Flow Area
Flow Calculation
Froude Check
Froude Depth Adjustment
Head Rate Creep Factor
Head Rate Limit Minimum
Head Rate Limit
Interpolate Cross-Sections
Interpolate Culvert Inverts
M Channel Approach
M11 Network
Manhole Approach
Manhole Default C Exit Coefficient
Manhole Default Loss Approach
Manhole Default R Exit Coefficient
Manhole Default Side Clearance
Manhole Default Type
Manhole K Maximum Bend/Drop
Manhole Minimum Dimension
Manholes at All Culvert Junctions
Maximum Operational Controls
Minimum Channel Conveyance Length
Minimum Channel Storage Length
Minimum NA Pit
Minimum NA
Momentum Equation
Order Output
Output Data Types
Output Folder
Output Interval
Output Times Same as 2D
Pit Channel Offset
Pit Default 2D Connection
Pit Default Extrapolate Q Curve
Pit Default Road Crossfall
Pit Inlet Database
Pit Search Distance
Read File
Read GIS BC
Read GIS IWL
Read GIS Manhole
Read GIS Network
Read GIS Node
Read GIS Pits
Read GIS Table Links
Read GIS WLL Points
Read GIS WLL
Read Operating Controls File
S Channel Approach
Set IWL
Set Variable $\langle$name$\rangle$
Spatial Database
Start Output
Storage Above Structure Obvert
Structure Flow Levels
Structure Losses Approach
Structure Losses SX
Structure Losses
Structure Routines
Taper Closed NA Table
Timestep
Trim XZ Profiles
Vel Rate Creep Factor
Vel Rate Limit Minimum
Vel Rate Limit
Weir Approach
Weir Flow
WLL Approach
WLL Automatic
WLL No Weirs
WLL Vertical Offset
WLLp Interpolate Bed
Write Check Files
XS Database

Table B.1: **TUFLOW Classic/HPC ECF Commands**
Command	Solver	Description
Arch Bridge Minimum Blockage (%) == [ {5} \| $\langle$ min_pblockage $\rangle$ ]	Classic and HPC	Sets the minimum blockage applied in the arch bridge flow calculation (see Section 5.8.3.2). The default value is 5 (%).
BC Database == [ $\langle$ .csv_file $\rangle$ ]	Classic and HPC	Sets the active BC Database file, as described in Section 8.6. The file is usually created using spreadsheet software such as Microsoft Excel. If the BC Database is specified in the TUFLOW .tcf file, it is set as the active database for both 2D and 1D models. However, the active database can be changed at any stage in the .tbc and .ecf files by repeating the command with the new database set as the $\langle$ .csv_file $\rangle$. A BC Database must be specified before any of the other BC commands are used.
BC Event Name == [ $\langle$ bc_event_name $\rangle$ ]	Classic and HPC	Sets the active BC name to be substituted where $\langle$ bc_event_text $\rangle$ (see BC Event Text) occurs in the BC Database. See Section 8.6.2 for a description of how the BC event commands operate. This command is normally specified in the .tcf file, and is only used in the .ecf file if the event boundaries vary by event within the model. For example, it may be set to “Q100” to read in the 100 year catchment inflows, then set as “H010” to read in the 10 year ocean levels for the downstream boundary. Note that, in this case, the locations of the catchment inflows and downstream boundaries would have to be placed in two separate GIS layers, with each layer read using Read GIS BC after the relevant BC Event Name command as shown below: BC Event Name == H010 Read GIS BC == gis\1d_bc_head_boundaries.shp BC Event Name == Q100 Read GIS BC == gis\1d_bc_flow_boundaries.shp
BC Event Text == [ $\langle$ bc_event_text $\rangle$ ]	Classic and HPC	Sets the text in the BC Database that is to be substituted by the BC Event Name command value. See Section 8.6.2 for a description of how the BC event commands operate. For 1D/2D models this command only needs to be specified in the .tcf file. It would only be used in the .ecf file for 1D only models or if for some reason the $\langle$ bc_event_text $\rangle$ value needs to change prior to reading the 1D BCs. Also see BC Event Text for the .tcf file if the model is 1D/2D. The $\langle$ bc_event_text $\rangle$ value can be changed at any stage by repeating this command in the .ecf file, although it is strongly recommended that the $\langle$ bc_event_text $\rangle$ value is standardised across all models and the command is only specified once.
Bridge Flow == [ Method A \| {Method B} ]	Classic and HPC	Controls the method for calculating bridge flows. Method A uses the original ESTRY bridge routine. Method B (the default), is based on Method A, but provides improved stability particularly when the bridge is flowing at shallow depths or is wetting and drying. Method B also does not force the loss coefficient to be a minimum of 1.5625 once the bridge obvert is surcharged (Method B uses the value as specified in the BG table). Refer to Section 5.8.2.1 for further information.
Bridge Zero Coefficients == [ {DEFAULT} \| OFF \| $\langle$ Cd $\rangle$, $\langle$ DLC $\rangle$, $\langle$ ELC $\rangle$, $\langle$ XLC $\rangle$ ]	Classic and HPC	Changes the default BB bridge (Section 5.8.2.4) channel coefficients applied to zero (0.0) attribute values in the 1d_nwk layer(s). This command is not used for B bridge channels. The four values and their associated 1d_nwk attributes are: Cd: Bridge deck pressure flow surcharge coefficient specified by the HConF_or_WC attribute (Default = 0.8). DLC: Bridge deck energy loss coefficient when fully submerged and not under pressure flow. Specified by the WConF_or_WEx attribute (Default = 0.5). ELC: Unadjusted entrance loss coefficient specified by the EntryC_or_WSa attribute (Default = 0.5). The entrance loss coefficient applied is adjusted every timestep according to the approach velocity, as discussed in Section 5.8.2.4. XLC: Unadjusted exit loss coefficient specified by the ExitC_or_WSb attribute (Default = 1.0). The exit loss coefficient applied is adjusted every timestep according to the departure velocity, as discussed in Section 5.8.2.4. For example, Bridge Zero Coefficients == 0.75, 0.3, 0.5, 0.8 changes the default value for Cd, DLC, ELC and XLC used for any zero (0) attribute values in 1d_nwk layer(s). DEFAULT (which is the default setting) will set any zero values to the default values mentioned above. OFF will allow a zero value to be applied to the ELC and XLC loss coefficients. Cd and DLC cannot be non-zero, therefore, if OFF is specified these will always have their default value above applied if the 1d_nwk attribute is zero.
Conveyance Calculation == [ CHANGE IN RESISTANCE \| {ALL PARALLEL} ]	Classic and HPC	If set to CHANGE IN RESISTANCE, the parallel channel analysis splits the cross-section into separate parallel channels based on wherever there is a change in resistance (due to different relative resistance, material type or Manning’s n values). If set to ALL PARALLEL (the default), a parallel channel is created for every X (distance across section) value. This approach does not cause conveyance reducing with height warnings. Refer to Section 5.7.3.
Create Nodes == [ {ON} \| OFF ]	Classic and HPC	If no node is found snapped to the end of a channel a new node is automatically created. The ID of the node is the first ten characters of the channel ID with a “.1” or “.2” extension. “.1” is used if the node is at the start of the channel and “.2” if at the end. If more than one channel is connected to the created node, the channel ID that occurs first alphanumerically is used. The automatic creation of nodes can be switched off using the OFF option. For further information see Section 5.13.1.
CSV Format == [ HORIZONTAL \| {VERTICAL} ]	Classic and HPC	If set to HORIZONTAL, writes the 1D .csv output file (Section 15.3) with the head/flow/velocity values for a node/channel in rows. The default is to write the values in columns.
CSV Maximum Number Columns == [ $\langle$ max_col $\rangle$ ]	Classic and HPC	Default value recommended. Expand to find out more about the legacy settings. This is a legacy command that applies to formats prior to the default .csv output for the 2016-03 release. Used to specify a maximum number of columns for 1D .csv output files. The default setting is limitless. Refer also to the .tcf command CSV Maximum Number Columns.
CSV Time == [ {DAYS} \| HOURS \| MINUTES \| SECONDS ]	Classic and HPC	Use the .tcf CSV Time command instead. Expand to find out more about the legacy settings. Specifies the time values of 1D .csv outputs. The default is DAYS but can be changed to HOURS, MINUTES or SECONDS. The .tcf command CSV Time can be specified to apply to both 1D and 2D .csv outputs.
Culvert Critical H/D == [ {OFF} \| $\langle$ critical_h/d $\rangle$ \| $\langle$ v1 $\rangle$ \| $\langle$ v2 $\rangle$ \| $\langle$ v3 $\rangle$ ]	Classic and HPC	Sets the H/D value to be used for determining whether outlet control Regimes E and F take preference over the inlet control Regimes B or L. H is the upstream head above the culvert sill and D is the culvert height. If H/D exceeds $\langle$ critical_h/d $\rangle$ Regime E or F is used, otherwise the regime with the lower discharge (along with other tests) is used. The default is OFF (i.e. infinitely large H/D). Three options are additionally available: v1 = Critical H/D value at culvert inlets connected to at least one open channel. v2 = Critical H/D value at culvert inlets connected to a pit channel (and not connected to any open channels). v3 = Critical H/D value at culvert inlets at culvert only junctions (no open channels or pits). Default values are 99999. (i.e. no critical H/D values applied). If only one value is specified, this is applied to all three. Specifying OFF applies 99999 to all three values.
Culvert Flow == [ {Method E} \| Method $\langle$letter$\rangle$ ]	Classic and HPC	Controls the method for calculating culvert flows. Options include: Method A is the original ESTRY culvert routines. Method B is an adaptation of Method A to include regimes K and L (see Figure 5.4). Method B also offers improved stability, smoother transitions between flow regimes and corrects very occasional mass conservation errors under certain flow regimes. Method C is a slight improvement on Method B for flow Regime C (see Figure 5.4). Method D includes further improvements on Method C and corrects a bug for Regime E. Method E is the current default and incorporates minor improvements for transitioning between Regimes A and B, and between inlet and outlet controlled regimes, for circular culverts. Method G (introduced in the 2023-03-AC release) includes an enhancement to adverse slope culvert flux calculation. Prior to 2023-03-AC, significant exit loss could be applied at the exit of an adverse slope culvert if the outlet node is dry or close to dry. This is caused by the misrepresentation exit flow area and exit velocity. Method G fixes this. Methods A, B, C and D are provided for backward compatibility only.
Culvert Zero Coefficients == [ DEFAULT \| {OFF} \| v1, v2, v3, v4, v5 ]	Classic and HPC	Sets the default culvert coefficients if they are set to zero (0) in the 1d_nwk layer(s). The five affected attribute values are as per the following: v1 Circular culvert inlet controlled contraction coefficient (Width_Cont attribute). v2 Rectangular and irregular culvert height contraction coefficient (Height_Cont attribute). v3 Rectangular and irregular culvert width contraction coefficient (Width_Cont attribute). v4 Culvert inlet loss coefficient (Entry_Loss attribute). v5 Culvert outlet loss coefficient (Exit_Loss attribute). For example, Culvert Zero Coefficients == 1.0, 0.6, 0.9, 0.5, 1.0 sets any zero (0) and NULL coefficient values in 1d_nwk layers to the corresponding value from this command. Any non-zero and non-NULL values remain unchanged. DEFAULT sets zero coefficients to the default values of 1.0, 0.6, 0.9, 0.5 and 1.0. OFF (default) doesn’t apply this feature and if the 1d_nwk attributes are empty (See Table 5.4): For a circular culvert 1,1,0,0 is used. For a rectangular culvert 0.6,0.9,0,0 is used.
Depth Discharge Database == [ $\langle$ depth_discharge_dbase.csv $\rangle$ ]	Classic and HPC	Specifies the depth discharge database file that references the depth-discharge curves for non-operated Q channels. Mandatory if the model has any Q channels. Performs the same function as Pit Inlet Database. The same database file can be used for both Q channels, Q pits and pump channels.
Depth Limit Factor == [ {10} \| $\langle$ value $\rangle$ ]	Classic and HPC	Sets the depth limit for detecting instabilities. The default is set to 10, therefore the water level must exceed ten times the depth of the CS or NA table before an instability is triggered. See Section Section 5.13.3. Specifying a value greater than one extends the cross-section hydraulic properties and nodal storages above the highest elevation. For example, if a value of 2 is specified, this will allow water levels to reach twice the depth where depth is the difference between the highest and lowest elevations in the table. Cross-section hydraulic properties above the highest elevation are calculated based on the flow width remaining constant at the width of the highest elevation in the table. If the hydraulic properties are calculated from a cross-section profile, it uses the effective flow width as shown in the .eof file (it does not use the storage width) – this preserves the effect of any variation in relative roughness across the cross-section. All other hydraulic property sources use the storage width, and any relative roughness effects are ignored once the water level exceeds the highest elevation. Also note that the wetted perimeter remains constant above the highest elevation; ie. it is not increased on the vertical as the flood level rises. Cross-section properties of bridge channels are not affected by this command. Nodal storage properties extend upwards by keeping the surface area constant above the highest elevation in the table.
Flow Area == [ {EFFECTIVE} \| TOTAL ]	Classic and HPC	Sets the default method for calculating flow area at a channel cross-section when ESTRY calculates the hydraulic properties from a cross-section XZ profile table. The default is EFFECTIVE area, which means that the flow area is the sum of the areas divided by the relative resistance factor. TOTAL area ignores the relative resistance factor when calculating area, but uses it to set the wetted perimeter and hydraulic radius values. Either method gives the same channel conveyance. If the relative resistance across the profile is not specified or constant at a value of one, effective and total area are the same. The effective area method produces a velocity that applies to the main channel (where the relative resistance is set to one). The total area approach produces a velocity depth and width averaged, and typically underestimates the main channel velocity. The recommended approach is to use effective area. See Section 5.7.4 for a more detailed discussion.
Flow Calculation == [ Method A \| {Method B} ]	Classic and HPC	Method A is the original ESTRY channel flow routine. Method B corrects an anomaly that would sometimes incorrectly output 1D flow values where the channel flow regimes are oscillating every half timestep (for example, between super and sub-critical flow regimes). Where the channel is switching flow regimes between timesteps (nearly always the case), the correct flow is calculated. This fix also affects the flow in/out of 2D SX connections if the connected 1D channel is oscillating every half timestep. The fix does not change 1D water level and velocity results, unless they are influenced by changes due to any effects on SX flows. Use Method A only for backward compatibility.
Froude Check == [ {1} \| $\langle$ froude_no $\rangle$ ]	Classic and HPC	Sets the minimum Froude Number that upstream controlled friction flow may occur in “S” channels. Improved stability may occur in steeply flowing areas if $\langle$ froude_no $\rangle$ is less than 1. $\langle$ froude_no $\rangle$ cannot be below zero and would normally not exceed 1.
Froude Depth Adjustment == [ {ON} \| OFF ]	Classic and HPC	Switches ON or OFF an additional upstream controlled friction flow check for S channels (a similar check is used for 2D domains – see Section 7.5.2). Only set to OFF for backward compatibility.
Head Rate Creep Factor == [ $\langle$ value $\rangle$ \| {1.2} ]	Classic and HPC	Specifies rate at which the Head Rate Limit value changes.
Head Rate Limit == [ ON \| {OFF} \| $\langle$ hrl $\rangle$ ]	Classic and HPC	Specifies the head rate limit applied to nodes. This feature can be used to stabilise problematic 1D nodes, but should be used with caution and mass balance checks must be made to ensure there is no significant mass loss or gain. It is particularly useful where a node “bounces” temporarily and is prevented from becoming unstable. The maximum amount the water level can change in half a timestep is the $\langle$ hrl $\rangle$ value after any adjustment by the Head Rate Creep Factor. The $\langle$ hrl $\rangle$ is adjusted up and down depending on the stability of the node in a similar approach used for Vel Rate Limit. If the ON option is used, the $\langle$ hrl $\rangle$ value is set to 0.1.
Head Rate Limit Minimum == [ $\langle$ hrlmin $\rangle$ \| {0.001} ]	Classic and HPC	Specifies the minimum head rate limit that can occur. See Head Rate Limit.
Interpolate Cross-Sections == [ {ON} \| OFF ]	Classic and HPC	If set to ON (the default), any channels that don’t have a cross-section have their cross-section properties interpolated using the nearest cross-sections attached to other channels. See Section 5.7.7 for details on the process used. Set to OFF to disable this feature and force every channel to have a cross-section.
Interpolate Culvert Inverts == [ {ON} \| OFF ]	Classic and HPC	If set to ON (the default), any culverts that don’t have an invert (i.e. a -99999 value was assigned to the invert attribute(s) and there were no inverts assigned via any pits or nodes snapped to the culvert ends) have their invert(s) interpolated using the nearest assigned inverts of connected culverts/pipes. Set to OFF to disable this feature.
M Channel Approach == [ Method A \| {Method B} ]	Classic and HPC	Sets the matrix interpolation approach for M channel data (Section 5.9.1). Method A is the original interpolation approach which uses a 4 value interpolation routine that, especially along the 0 flow diagonal, might not interpolate as accurately as using a triangular (3 point) technique. The main issue with the 4 point routine is that a slightly positive or negative flow of the wrong sign may result when interpolating close to the zero flow diagonal. Method B uses an improved method. It uses a triangular interpolation with the long side of the triangle parallel to the zero flow diagonal, and does not experience the problems Method A has when interpolating close to the zero flow diagonal.
M11 Network == [ $\langle$ .nwk11_file $\rangle$ ]	Classic and HPC	Legacy Command. Expand to find out more about the legacy settings. Sets the active MIKE 11 network file as $\langle$ .nwk11_file $\rangle$. The file is used to extract link, cross-section and other information using 1d_nwk attributes. Topo_ID must be set to “$Link”. For more details see the 2018 TUFLOW Manual. This command must be specified before the relevant Read GIS Network command. The command may be used at any point to change the active MIKE 11 network file.
Manhole Approach == [ METHOD A \| METHOD B \| {METHOD C} ]	Classic and HPC	Sets the automatic manhole definition approach. See Section 5.11.4.1. Method A is the original approach which has been found to be too conservative (i.e. higher losses and therefore higher flood levels) as indicated by users. Method B, incorporates a few bug fixes found in Method A. Method C (the default) incorporates further bug fixes affecting manholes using the Engelund approach for calculating losses. If using METHOD B, sensitivity testing the effects of METHOD C versus METHOD B should be carried out to check for any unacceptable differences.
Manhole Default C Exit Coefficient == [ $\langle$ K_CE $\rangle$ \| {0.25} ]	Classic and HPC	For C (circular) manholes, sets the default K coefficient for flow out of the manhole and into the out flowing culvert(s). The default value is 0.25. See Section 5.11.4.
Manhole Default Loss Approach == [ NONE \| {ENGELUND} \| FIXED ]	Classic and HPC	Sets the default loss approach to be used at automatically generated manholes, and manholes where no loss approach is specified. The default is ENGELUND (see Section 5.11.4 for a description on the different approaches).
Manhole Default R Exit Coefficient == [ $\langle$ K_RE $\rangle$ \| {0.5} ]	Classic and HPC	For R (rectangular) manholes, sets the default K coefficient for flow out of the manhole and into the out flowing culvert(s). The default value is 0.5. See Section 5.11.4.
Manhole Default Side Clearance == [ $\langle$ value_m $\rangle$ \| {0.3} ]	Classic and HPC	For C (circular) manholes, sets the default side clearance in metres from the side of the largest culvert to the side of the manhole chamber (i.e. if the diameter of the chamber is not specified, the diameter is set to the width/diameter of the largest culvert plus twice the side clearance). For R (rectangular) manholes, sets the default side clearance from the side of the culvert(s) to the side of the manhole chamber. If the width of the chamber is not specified, the width is set to the greatest incoming or outgoing width, where the width is calculated as the sum of the incoming/outgoing culvert widths/diameters, plus twice the side clearance for the sides, plus twice the side clearance for the space between each incoming/outgoing culvert if more than one incoming or outgoing culvert exists. The default side clearance value can be overridden by specifying a negative width for a manhole in a 1d_mh layer. The side clearance applied will be the absolute value of the 1d_mh Width attribute, and the above approach will be used to determine the manhole width/diameter. See Section 5.11.4.
Manhole Default Type == [ C \| J \| R \| CR \| {CJR} ]	Classic and HPC	Sets the default type of manhole to be used at automatically generated manholes, and manholes where no type approach is specified. C is for circular manholes; R for rectangular manholes; J for junctions (i.e. no chamber); and CR and CJR are for a combination of C, R and J depending on the size/configuration of the connecting culverts (see Section 5.11.4 for further details). The default is CJR. CR assigns an R type if one or more of the below are true, otherwise a C type is assigned. The number of barrels of any culvert is greater than one. There are any parallel culverts (i.e. two or more culverts with the same nodes and the culverts are digitised in the same direction). The diameter of at least one circular culvert (C channel) exceeds 1.2m. The width of at least one rectangular culvert (R channel) exceeds 0.45m. CJR uses the same logic as described above for CR, however, it will assign a J type instead of a C or R if all of the below are true. The J type in this case is to cover the situation where access is possible via the culverts, rather than via a manhole. The number of barrels of all connected culverts must be one, and there are no parallel culverts (i.e. two or more culverts with the same nodes and the culverts are digitised in the same direction). There is only one inlet and one outlet culvert. The diameter of at least one circular culvert exceeds 1.8m, or the width and height of at least one rectangular culvert exceeds 1.2m and 1.8m.
Manhole K Maximum Bend/Drop == [ $\langle$ max_K_bd \| {4.0} ]	Classic and HPC	Sets the maximum K energy loss coefficient that can occur for the sum of the loss coefficients for bends and drops at a manhole when using the Engelund approach. See Section 5.11.4.4.
Manhole Minimum Dimension == [ $\langle$ min_width_m \| {1.05} ]	Classic and HPC	Sets the minimum diameter for C manholes and minimum width and length for R manholes. The value is usually controlled by the minimum dimensions needed for access to manhole chambers, not by any hydraulic efficiency requirements. See Section 5.11.4.
Manholes at All Culvert Junctions == [ {ON} \| OFF ]	Classic and HPC	If set to ON (the default), manholes are automatically created at all culvert junctions. See Section 5.11.4 for more information.
Maximum Operational Controls == [ {1000} \| ]	Classic and HPC	Sets the maximum number of operational control channels (Section 5.10.
Minimum Channel Conveyance Length == [ {0} \| $\langle$ length_m $\rangle$ ]	Classic and HPC	Automatically increases the conveyance (and storage) length to $\langle$ length_m $\rangle$ if the channel’s length is less than $\langle$ length_m $\rangle$. The default setting is zero (i.e. no change to any channel’s length). Does not apply to pit channels.
Minimum Channel Storage Length == [ {0} \| $\langle$ length_m $\rangle$ ]	Classic and HPC	If a channel’s length is less than $\langle$ length_m $\rangle$, then $\langle$ length_m $\rangle$ is used for calculating any storage contributions from the channel widths. It does not affect the channels bed resistance, conveyance or slope. Can be useful to add additional storage for stability reasons to nodes at the ends of very short channels. If using this command, care must be taken not to excessively add additional storage causing results to be distorted. Generally, adding an appropriate amount of storage for stability reasons does not distort results, however, it is strongly recommended that sensitivity tests are carried out to cross-check the effect of any additional storage, and that any adverse effects are corrected.
Minimum NA == [ {1} \| $\langle$ value $\rangle$ ]	Classic and HPC	Sets the minimum surface area (m²) in all NA tables (except for the upstream (ground) nodes of pit channels). The default value is one (1m²). This command is useful for stabilising 1D nodes that have very small storages, particularly at shallow depths. If using this command, care must be taken not to excessively add additional storage causing results to be distorted. Generally, adding an appropriate amount of storage for stability reasons does not distort results, however, it is strongly recommended that sensitivity tests are carried out to cross-check the effect of any additional storage, and that any adverse effects are corrected. The percentage (%) option is provided which sets the minimum NA value for each node based on a percentage of the maximum nodal area value for the node.
Minimum NA Pit == [ {1} \| $\langle$ value $\rangle$ ]	Classic and HPC	Sets the minimum surface area (m²) of the upstream (ground) nodes of all pit channels. The default value is one (1m²). This command was introduced to differentiate upstream pit channel nodes from the Minimum NA setting. If the pit channel is connected to a 2D domain, this storage has no influence on the hydraulic computations, and increasing the value has no stability benefits.
Momentum Equation == [ PRE 2003-08-AD ]	Classic and HPC	Default value recommended. Expand to find out more about the legacy settings. Sets treatment of the effective flow width above the top of a cross-section to the method used prior to Build 2003‑08‑AD to provide backward compatibility. After this build, the effective flow width at the top of a cross-section is stored and used to extend the effective flow area above the highest point in the cross-section. Prior to this build, the top storage width was used for the effective flow width for flows above the top of the cross-section. This may only affect results where relative resistance varies across a cross-section, and flow occurs above the top of the cross-section, and effective flow area is being used.
Order Output == [ {ON} \| OFF ]	Classic and HPC	Alphanumerically orders 1D output according to the node and channel IDs. The exception is the boundary condition data in the .eof file.
Output Data Types == [ {H Q S V} \| $\langle$ data_types $\rangle$ ]	Classic and HPC	Similar to the .tcf map output command Map Output Data Types, this command controls which 1D data types to output, The options are: A for flow area at channels (m²) E for energy (m) H for water level (m³) Q for flow at channels (m³/s) Qi integral flow at channels (m³) S for structure and grouped structure output (see Section 11.3.4) V for velocity (m/s) Vol volume at nodes (m³)
Output Folder == [ $\langle$ folder $\rangle$ ]	Classic and HPC	Redirects all ESTRY (1D) output data to another folder. Typically used to write output to your local drive instead of filling up the network or to keep results separate to the input data. A URL path can be used (e.g. \bmtserv\Computer001\tuflow\results), which is useful for running simulations on other computers, but having the output directed to your local drive or other location (your drive will need to be shared). The default location for 1D output is that specified using Output Folder in the .tcf file for 1D/2D models.
Output Interval == [ $\langle$ time $\rangle$ ]	Classic and HPC	Use the .tcf Time Series Output Interval command instead. Expand to find out more about the legacy settings. The output interval for ESTRY output. The default units are hours; however, seconds may be used if the “(s)” option is specified. If the command is omitted, output is at every computational timestep.
Output Times Same as 2D == [ {ON} \| OFF ]	Classic and HPC	For 1D/2D models, the times for 1D output are, by default, the same as that of the 2D domain(s) time series output (see Start Time Series Output and Time Series Output Interval), unless no 2D time series output (2d_po layers) has been specified, in which case Start Output and Output Interval are used. For backward compatibility or to use different times for 1D time series output, set to OFF. This change was made so that both 1D and 2D time series data could be output to the_TS. file, allowing graphing of 1D and 2D time series data within a GIS (see Section 15.3.4). This command is ignored for 1D only (ESTRY) models.
Pit Channel Offset == [ $\langle$ length_m $\rangle$ ]	Classic and HPC	Sets the display, not computed, length in metres of pit channels in 1D output and the1d_nwk check files. The channel is displayed on a north to south alignment. See Section 5.11.2.
Pit Default 2D Connection == [ {} \| $\langle$ Conn_1D_2D $\rangle$ ]	Classic and HPC	Sets the default value for the 1d_nwk Conn_1D_2D attribute. For example, if set to SX, then if the 1d_nwk Conn_1D_2D attribute for a pit is empty, SX will be used, saving the user to specify SX at pits. To disconnect a pit NO can be used for the Conn_1D_2D attribute. It is also possible to have the L and Z options at the one pit (e.g. SXLZ). See Section 5.11.2.
Pit Default Extrapolate Q Curve == [ {ON} \| OFF ]	Classic and HPC	TUFLOW automatically extrapolates Q and VPI pits depth discharge information beyond the last value in the depth-discharge curve using an orifice flow equation. To not extrapolate the depth-discharge curve the 1D command “Pit Default Extrapolate Q Curve == OFF” can be used. See Section 5.11.2.
Pit Default Road Crossfall == [ $\langle$ slope $\rangle$ ]	Classic and HPC	Increases the depth at Q pits based on the height of an imaginary triangle of the road cross-section with a crossfall slope of $\langle$ slope $\rangle$. $\langle$ slope $\rangle$ is Vertical/Horizontal as a fraction (not percentage). The imaginary triangle has the same area as the vertical flow area in the 2D cell the pit is connected to (i.e. the triangle’s area is the depth in the 2D cell times the width of the cell). Once the horizontal width of the triangle is greater than the width of the 2D cell, the formula changes to give an equivalent area based on a trapezoid consisting of the triangle plus a rectangle for the remaining area in excess of the triangle. See Section 5.11.3.1.
Pit Inlet Database == [ $\langle$ pit_inlet_dbase.csv $\rangle$ ]	Classic and HPC	Specifies the pit inlet database file that references the depth-discharge curves for Q pit channels. Mandatory if the model has any Q pit channels. Performs the same function as Depth Discharge Database. The same database file can be used for both Q channels and Q pits. See Section 5.11.3 for more information.
Pit Search Distance == [ {0.0} \| $\langle$ psd_m $\rangle$ ]	Classic and HPC	Set the distance (radius) in metres to search for the closest node to automatically connect pits into the 1D network where pits are not snapped to channel ends. Pits connected via this feature are displayed in the 1d_nwk_C_check layer as occurring from the location of the pit to the node, ie. Pit Channel Offset is not used to display the pit channels created. The pits are also displayed in the 1d_nwk_N_check layer using a different colour to those pits that are snapped directly to a channel end. This command may be used several times in the .ecf file with the most recent occurrence applying at the time a pit is processed. A value of 0.0 (the default), disables the pit search feature. See Section 5.11.2.
Read File == [ $\langle$ file $\rangle$ ]	Classic and HPC	Directs input to another file. When finished reading $\langle$ file $\rangle$, ESTRY returns to reading the .ecf file. This command is particularly useful for projects with a large number of simulations. Repetitive commands are grouped and placed in another text file. If one of these commands changes, the command only has to be edited once, rather than in every .ecf file. This command can be used to redirect file(s) up to a maximum of ten levels.
Read GIS BC == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	Reads the location and attributes of 1D model boundary conditions, as described in Section 8.4.
Read GIS IWL == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	Reads initial water level elevations at nodes from a 1d_iwl GIS layer. The 1d_iwl layer contains points snapped to nodes in the 1d_nwk layer(s). The first attribute of the layer must be the initial water level as a number (float or decimal). The layer can define any number of the nodes (it does not need to define all the nodes). The command can be used any number of times to access more than one 1d_iwl layer. The command can be used in the .tcf and .tef files as 1D Read GIS IWL. See Section 8.9.1.1 for further information.
Read GIS Manhole == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	Reads manhole locations and attributes from a GIS 1d_mh layer as described in Section 5.11.4.2. Any number of 1d_mh layers may be read by repeating this command. Manholes that occur in the same location will override each other with the last manhole processed prevailing. Manholes processed using this command will overwrite any automatically generated manholes. Automatically generated manholes may be individually disabled by digitising points and specifying “NO” for the Loss_Approach attribute – see Table 5.28.
Read GIS Network == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	Reads channel and node locations and attributes from a GIS 1d_nwk layer as described in Sections 5.4 and 5.13. Any number of 1d_nwk layers may be read by repeating this command. If accessing external cross-section databases such as MIKE 11 .txt file, the XS Database command must be specified before this command to set the active cross-section database.
Read GIS Node	Classic and HPC	Reads node locations and attributes from a GIS 1d_nd layer as described in Table 5.31. Any number of 1d_na layers may be read by repeating this command. This is an alternative option to the 1d_nwk Read GIS Network command, but applies to 1D nodes only.
Read GIS Pits == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	Reads virtual pipe locations and attributes from a GIS 1d_pit layer, as described in Section 5.12. If using the virtual pipe functionality a Pit Inlet Database is required.
Read GIS Table Links == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	Reads links to tabular input of cross-section profiles (1d_xs – see Section 5.7), nodal surface areas (1d_na – see Section 5.13.2.1) or bridge loss coefficients (1d_bg – see Section 5.8.2). The first attribute is the filename (can include a file path) of the .csv or similar file containing the table. This attribute can be setup as a hotlink, allowing the file to be opened in spreadsheet software via a GIS program.
Read GIS WLL == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	Reads water level lines (WLL) and polygons for defining 1D map output, see Section 11.2.4 for further information.
Read GIS WLL Points == [ $\langle$ gis_layer $\rangle$ ]	Classic and HPC	For WLL Approach Method B, reads elevation and material points generated from the WLLs. This allows more accurate velocity and flood hazard mapping. See Section 11.2.4.2 for more information.
Read Operating Controls File == [ $\langle$ .toc_filename $\rangle$ ]	Classic and HPC	Directs input to the Operational Controls file (.toc) containing operating rules applied to hydraulic structures, pumps and other controllable devices. More than one .toc file can be created and accessed should there be a need to break the control definitions into several files (for example, all pump controls could be placed in one file and sluice gate controls in another). Refer to Section 5.10 for more information.
S Channel Approach == [ PRE 2004-06-AA \| METHOD A \| {METHOD B} ]	Classic and HPC	PRE 2004-06-AA provides backward compatibility of S channel types for pre 2004-06-AA models. METHOD A improved the S channel algorithm after Build 2004-06-AA. The new approach utilises the approach used by G channels for handling situations when the downstream end of a channel is dry or free-overfalling. METHOD B (the default) was introduced for the 2010-10 release after rigorous testing on steep, fast flowing channels showed improved performance over METHOD A. METHOD B only applies the G channel approach in adverse flow conditions (i.e. when the water surface gradient is of opposite slope to the channel bed slope), whereas METHOD A tests for and may apply the G channel algorithm on any S channel, and was found in extreme situations to cause some minor choking of the flow down the channel.
Set IWL == [ $\langle$ IWL $\rangle$ ]	Classic and HPC	Sets the initial water level at all nodes to $\langle$ IWL $\rangle$. Initial water levels different to $\langle$ IWL $\rangle$, for example in a lake, can be set using the “Read GIS IWL” command.
Set Variable $\langle$name$\rangle$ == [ $\langle$value$\rangle$ ]	Classic and HPC	Define user variables for use within the control files, see Set Variable.
Spatial Database == [ OFF \| TCF ]	Classic and HPC	Optional when using the GeoPackage input format. Sets the database to use for subsequent inputs. For more information see Section 4.4.3.
Start Output == [ $\langle$ time_in_hours $\rangle$ ]	Classic and HPC	Use the .tcf Time Series Output Interval command instead. Expand to find out more about the legacy settings. The simulation time in hours when output commences. If the command is omitted, the simulation start time is used.
Storage Above Structure Obvert == [ CHANNEL WIDTH \| $\langle$ value $\rangle$ \| {5} ]	Classic and HPC	Defines how the surface area is to be contributed to the NA table above the obvert of B, C and R channels, it does not apply to manually defined NA tables. The default is to apply 5% of the maximum surface area. The CHANNEL WIDTH option uses the top width of B and R channels and the diameter for C channels (see Section 5.13.3). Older models that used CHANNEL WIDTH (the default prior to 2006-03-AB) and require it for stability, will most likely need to adopt a smaller 1D Timestep. Alternatively, use of CHANNEL WIDTH is acceptable provided the additional storage that it adds to the model is relatively minor, or it can be demonstrated to not significantly influence results. If a value is specified, the channels width by half the channel length is applied (provided the UCS attribute is left blank or set to “Y” (yes) or “T” (true) between the invert and obvert, with $\langle$ value $\rangle$ applied above the obvert. If the (%) option is specified (the default), the value applied above the obvert is the percentage of the structure’s maximum surface area. The default setting is to use 5% of the structure’s maximum surface area above the obvert. If the (%) option is not specified, the value is in m² and is applied as a constant above the obvert. For C channels, the correct flow width in the section is applied (rather than the diameter), and for C and R channels, the Number_of attribute in the 1d_nwk layer is also used. Use this option where the storage contributed by B, C and/or R channels is significant (e.g. pipe model). Note, the reason a storage value of zero is not automatically used above the obvert is that a node cannot have zero storage. A value of zero can be used provided storages at the nodes is contributed by other channels, or a pit storage is applied or commands such as Minimum NA are used. If the only channels connected to a node are B, C and R channels, the NA table is extended vertically by 10m (32.8ft) above the highest obvert. Should water levels exceed this height, use Depth Limit Factor to extend the table further.
Structure Flow Levels == [ {ENERGY} \| WATER \| ENERGY UPSTREAM ]	Classic and HPC	For calculating structure flows sets, defines whether to use energy or water surface levels as the global default in the flow calculations. The default is to use ENERGY (upstream and downstream). As of the 2023-03 Release “ENERGY UPSTREAM” can be used, which uses energy for the upstream and water level for the downstream. The global default can be overridden channel by channel using the “E”, “H”, or “EH” optional flag for the 1d_nwk Type attribute (see Table 5.2).
Structure Losses == [ {ADJUST {EXCEPT BG TABLE}} \| FIX ]	Classic and HPC	If set to ADJUST, the entrance and exit losses of culverts and the bridge loss coefficients are adjusted according to the approach and departure velocities upstream and downstream of the structure. See Section for details. This setting can be overridden using an A (adjust) or F (fix) flag for B, C and R channels. If set to ADJUST EXCEPT BG TABLE (the default) only adjusts losses for culverts and automatically generated BG tables noting that in the latter it is only the deck loss component that is adjusted as the component specified via the 1d_nwk Form_Loss attribute is always treated as fixed. Any manually specified BG tables are not adjusted unless the “A” flag is used in the 1d_nwk Type attribute or “Structure Losses == ADJUST” is used without specifying “EXCEPT BG TABLE”. See Section 5.8.7 for details.
Structure Losses Approach == [ METHOD A \| {METHOD B} ]	Classic and HPC	METHOD A is the original ESTRY routine. METHOD B (the default) is an enhancement over METHOD A. It is the same as METHOD A, except that if reverse flow occurs in the approach or departure primary channels (reverse flow is when flow is in the opposite direction to the channel’s digitised direction), the adjustment of entrance and exit losses is based on the flow direction, not the digitised direction.
Structure Losses SX == [ ADJUST \| ADJUST SKEW \| {FIX} ]	Classic and HPC	Extends the adjustment of contraction and expansion losses for 1D culverts and bridges to automatically adjust at 1D/2D SX connections. The “FIX” option is the default and is the approach taken in prior builds, i.e. no adjustment of the losses. The “ADJUST” (beta function) option takes the depth averaged velocities at SX cells and applies them as the approaching/departure velocities to adjust the entrance/exit loss coefficients of a 1D structure in the same manner as for a 1D/1D connection (see Section 5.8.7). The “ADJUST SKEW” (beta function) option also considers the skew angle of the 2D velocity relative to the 1D structure entrance/exit. By default, the geographical angle of a 1D structure entrance/exit is automatically calculated from the 1d_nwk GIS layer to calculate the normal velocity: $𝑉_{a𝑝𝑟𝑜𝑎𝑐ℎ} = u \times 𝑐𝑜𝑠(skew\ angle) + v \times sin(skew\ angle)$ The skew angle can be also specified manually using the “B” attribute in a 2d_bc SX layer with the following rules: If B = 0.01° ~ 360°, B defines the geometric angle of 1D structure entrance/exit. If B = -0.01° ~ -90°, B defines the absolute skew angle, i.e.: $𝑉_{a𝑝𝑟𝑜𝑎𝑐ℎ} = \sqrt{u^2 + v^2} \times 𝑐𝑜𝑠(skew\ angle)$ B attribute is normally left as zero, and in such case, the automatically calculated geometric angle of the connected 1D GIS network is used. To manually define a 0° angle, “B = 0.01°” can be specified where “0.01°” is rounded down to a geometric angle of 0°, while “B = -0.01°” is rounded up to an absolute angle of 0°. The “Zero Skew Angle” command can be used to make the cut-off value smaller than 0.01, in order to apply an even smaller user specified angle.
Structure Routines == [ ORIGINAL \| {2013} ]	Classic and HPC	Default value recommended. Expand to find out more about the legacy settings. ORIGINAL only allows structures available prior to Build 2013-12-AA to be available to force users to limit their use of structures in a legacy model. 2013 allows the use of the original structures, plus the many new structures introduced for Build 2013-12-AA. This includes access to operational structures and any other new structures added since Build 2013-12-AA.
Taper Closed NA Table == [ {ON} \| OFF ]	Classic and HPC	Reduces the second last surface area value gradually over 3 additional levels for nodes connected to only closed channels such as bridges and culverts. Also, for B and R channels, starts to reduce storage a 20% of the structures total depth below the obvert, to prevent a sudden change in surface area. This command is still to be further tested, but may offer additional stability in urban models with many closed structures.
Timestep == [ $\langle$ timestep_in_seconds $\rangle$ ]	Classic and HPC	1D/2D TUFLOW Classic or 1D Only ESTRY Simulations Specifies the fixed computational timestep of the simulation in seconds. Value must be greater than zero. Timesteps that divide equally into one minute or one hour are recommended. For example, 0.5, 1, 2, 3, 5, 6, 7.5, 10, 12, 15, 20, 30, 45, 60, etc. seconds. A 1D timestep different to the timesteps of the 2D domains may be specified for 1D/2D models, however the 1D timestep must not be greater than the smallest timestep of the 2D domains. If the 1D timestep is not equally divisible into the smallest 2D timestep, the 1D timestep is reduced automatically so that it is equally divisible. If this command is not specified in the .ecf file, the smallest 2D timestep is used. See Section 3.5.2 for details. 1D/2D TUFLOW HPC Simulations The 1D timestep for a HPC 1D/2D linked model represents the maximum limiting timestep the 1D solver can use. ESTRY uses an adaptive/varying timestep solution when used with the HPC solver. Both 1D and 2D solutions are always synchronising at the 2D target timestep, or a multiple of the 2D target timestep if the 1D timestep is sufficiently greater for the 2D to perform more than one step. If the 1D limiting timestep is less than half the 2D target timestep, the 1D proceeds in two or more steps eventually synchronising with the 2D timestep. Where there is not a one to one synchronisation of the 1D and 2D timesteps, a usually negligible mass error may occur and can be checked by reviewing the CME% values shown on the Console Window, the .tlf file or the _MB.csv file in the same manner as Classic. . See Section 3.5.2 for details.
Trim XZ Profiles == [ ON \| {OFF} ]	Classic and HPC	Trims the XZ profile extracted from Flood Modeller .dat files so that the treatment at the ends of the cross-section profile is similar to that used by Flood Modeller. If set to OFF the whole XZ profile is stored with the sections of the profile before and after the left and right markers disabled. However, the active end of the cross-section profile will extend to midway between the first/last disabled point and the last/first active point at either end of the profile. If set to ON, the points before and after the left and right markers are not stored, and the cross-section extent is not extended to midway to the first/last points nearest the left and right markers. To have similar compatibility with Flood Modeller, this command should be set to ON.
Vel Rate Creep Factor == [ $\langle$ value $\rangle$ \| {1.2} ]	Classic and HPC	Specifies rate at which the Vel Rate Limit value changes. This value is rarely changed from its default value of 1.2. See Vel Rate Limit for further discussion.
Vel Rate Limit == [ $\langle$ vrl $\rangle$ \| {0.2} ]	Classic and HPC	Specifies the velocity rate limit applied to non-inertial channels (structures). This value is rarely changed from its default value of 0.2. During a computation this value is adjusted downwards if a structure becomes unstable and upwards if stable using the Vel Rate Creep Factor value. An “L” is shown in the second space after velocity and flow time output in the .eof file, and also in the_TSF output, indicating if the velocity rate limit algorithm was applied. If a structure frequently has the velocity rate limit applied to it, checks should be made on structure configuration and on the results at the structure. For example, check the flow through the structure based on the upstream and downstream water levels is similar to that using desktop calculations or other software.
Vel Rate Limit Minimum == [ $\langle$ vrlmin $\rangle$ \| {0.0001} ]	Classic and HPC	Specifies the minimum velocity rate limit that can occur. See Vel Rate Limit.
Weir Approach == [ {Method A} \| Method B ]	Classic and HPC	This command specifies the approach taken to calculate submerged flow for ‘W’ type weirs (refer to Section 5.8.4.2). For all other weir types, the approaches used are discussed in Section 5.8.4.3. Method A (the default) utilises the Bradley submergence approach which after further analysis is the preferred approach. Method B was initially introduced to provide better stability for weirs embedded within 2D domains. In some situations, this approach was found to not converge very well and caused large head drops.
Weir Flow == [ Method A \| Method B \| {Method C} ]	Classic and HPC	Method A is the original ESTRY routine and only applies to W weirs. Method B is not recommended – only applies to W weirs. Method C (the default and introduced for the 2016-03 release), applies Method A for the original W weirs, provides some minor improvement to WW weirs, and otherwise has no influence for all other weir types introduced for the 2013-12 release. Note that for the 2016-03 release there is a general improvement to all new weirs introduced for the 2013-12 release when the weirs became drowned out. Previously it was possible for an instability (usually associated with a large head drop) and/or presence of NaNs in the results. The new approach does not experience this issue and is significantly more stable. There is no backward compatibility switch for this change.
WLL Approach == [ Method A \| {Method B} ]	Classic and HPC	If set to Method A uses the simpler approach for incorporating 1D output into SMS and GIS map output. Method B (the default) allows the use of elevation points and material values to more accurately map and animate 1D results. See Section 11.2.4 for details on Method B and the TUFLOW 2010 Manual on Method A (noting that Method A is no longer supported).
WLL Automatic == [ CULVERTS \| {OFF} ]	Classic and HPC	If set to CULVERTS, automatically generates 1D WLLs along culverts (C, R and I channels). The WLL will have the same width as the culvert width, and can save a lot of digitising for large pipe models! WLLs are placed a short distance from each end of the culvert channel, and also at each vertices along the channel line. See Section 11.2.4 for more details.
WLL No Weirs == [ ON \| {OFF} ]	Classic and HPC	If set to ON, TUFLOW will not assign any WLLs to 1D weir channels. This is useful where weir channels modelling flow over a bridge or culvert (especially those using the BW, CW or RW channel type) is in parallel to a B, C or R channel. In this instance, it is not known whether the B, C or R channel, or the W channel will be selected for assigning results to WLLs. To guarantee that the B, C or R channel is selected use this command with the ON option. See Section 11.2.4 for more details.
WLL Vertical Offset == [ $\langle$ dZ $\rangle$ \| {10} ]	Classic and HPC	Sets the vertical adjustment of WLL elevations in the mesh .2dm file. The value of 10 generally means that the 1D WLL output sits above the 2D cell output and is more visible (which presents data in order of increasing height). However, in 3D the 1D appears perched on top of the 2D. To show the WLL mesh at its correct height for 3D displays specify a dZ value of 0.0. This command only affects the .2dm file, so can be applied to a temporary .tcf file used solely to generate an alternative .2dm file (i.e. there is no need to carry out the hydraulic calculations). See Section 11.2.4 for more details.
WLLp Interpolate Bed == [ {ON} \| OFF ]	Classic and HPC	If set to ON (the default), sets the centre WLL point to the channel bed based on the processed data (rather than use any value from a WLLp layer). This forces the bed profiles in longitudinal profile plots using the ‑lp switch in the TUFLOW_to_GIS utility (see Section 17) to be based on that modelled, rather than that a DTM using WLLp values (which may sometimes occur above the water surface!). Also helps to show where the WLLp elevations are inconsistent with the channel bed when viewing in SMS or using TUFLOW_to_GIS. Doesn’t apply to culverts and bridges which use this approach regardless, and only applies to WLL Approach == Method B. See Section 11.2.4 for more details.
Write Check Files [Exclude \| Include \| None \| ALL] == [ $\langle$ prefix_list_or_file_prefix $\rangle$ ]	Classic and HPC	Creates GIS check files and text .csv files for quality control checking of model input data. A list of check files written are described in Section 14.7. Refer to the Write Check Files command in the .tcf file for an explanation of the various options and for examples. Specifying the Write Check Files command in the .tcf file will automatically also write the 1D check files for 1D/2D linked models. There is no need to specify Write Check Files in the .ecf file unless a different folder path for the files is desired.
XS Database == [ $\langle$ file $\rangle$ ]	Classic and HPC	Sets the active cross-section database as $\langle$ file $\rangle$. The extension of the file determines its format as follows: .txt indicates a MIKE 11 .txt processed data import/export file. The file must contain processed cross-section data; any raw data is ignored. .dat indicates a Flood Modeller data file containing XZ cross-section profiles – also see Trim XZ Profiles. .pro indicates a Flood Modeller processed cross-section data file. other file formats including a generic .csv format are planned to be incorporated. The assignment of cross-sections is carried out using 1d_nwk attributes as discussed in Section 5.7. This command must be specified before a Read GIS Network command. The command may be used at any point to change the active cross-section database.