1D Objects

1D objects are used to schematise 1D networks. The way flow is calculated in these 1D networks is described in the section 1D Flow.

• 1D Boundary Condition

• Channel

• Connection node

• Cross-section location

• Culvert

• Material

• Orifice

• Pipe

• Pump

• Pump map

• Weir

• 1D Wind shielding

1D Boundary Condition

Boundary condition for 1D connection nodes.

Layer name

boundary_condition_1d

Geometry

Point

Attributes

Table 19 1D Boundary condition attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Boundary type	type	integer	Yes	-	Sets the type to 1: Water level, 2: Velocity, 3: Discharge, 5: Sommerfeld, 6: Groundwater level or 7: Groundwater discharge
Time units	time_units	text	Yes	-	Units of the time step. Possible values: ‘seconds’, ‘minutes’, ‘hours’
Interpolate	interpolate	boolean	Yes	-	True: values will be interpolated between time steps. False: values will remain contant until the next time step
Time series	timeseries	text	Yes	[s, min, or h] and [m MSL, m/s, m/m, m³/s]	CSV-style table of ‘time_step,value’ pairs, separated by newline character.
Connection node ID	connection_node_id	integer	Yes	-	Foreign key reference to an ID in Connection node
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag

Notes for modellers

General notes

• 1D boundary conditions can only be applied to connection nodes that have a single connection to the rest of the network.

• The pipe, channel, or structure directly connected to the boundary condition must have exchange type isolated.

• 1D boundary conditions cannot be placed on the same connection node as a pump.

• 1D laterals placed on a connection node with a 1D boundary condition will be ignored.

• Surfaces and Dry weather flow mapped to a connection node with a 1D boundary condition will be ignored.

Time series

• Format the time series as Comma Separated Values (CSV), with the time (in minutes since the start of the simulation) in the first column and the value (units dependent on the boundary type) in the second column. For example:

  0,145.20
  15,145.23
  30,145.35
  45,145.38
  60,145.15
  

• Units used are:

  • Water level: m MSL

  • Velocity: m/s

  • Discharge: m³/s

  • Sommerfeld: m/m

  • Groundwater level: m MSL

  • Groundwater discharge: m³/s

• The time series string cannot contain any spaces or empty rows

• The boundary condition time series is stored in the simulation template and is not part of the 3Di model itself. It can be overridden when starting a new simulation, without the need to create a new revision of the schematisation.

• When posted to the 3Di server, the time steps will be converted to seconds

• For boundary types Velocity, Discharge and Sommerfeld, the drawing direction of the channel, pipe, or structure determines sign of the input value. For velocity and discharge, this means that if the 1D boundary condition is placed on the end connection node, positive values result in boundary outflow. For the Sommerfeld boundary, a positive gradient for a 1D boundary condition that is placed at the end connection node means that the waterlevel downstream is higher than upstream, i.e. this will result in boundary inflow.

• The time series must cover the entire simulation period.

• The time series values are interpolated between the defined times

• In case of multiple boundaries in one model: make sure they all have the same number of time series rows with the same temporal interval. This also applies if you have e.g. one 1D boundary and one 2D boundary.

• When editing the time series field in using SQL (sqlite dialect), use char(10) as line separator. The example time series shown above would look like this:

  '0,145.20'||char(10)||'15,145.23'||char(10)||'30,145.35'||char(10)||'45,145.38'||char(10)||'60,145.15'
  

Channel

A natural or artificial open channel. Channels can have a variable bed level, bed friction and cross section along their length. This information is stored in another object, the Cross-section location. A channel can have one or more cross-section locations, depending on the variability of the channel.

See Channels, culverts and pipes for more details.

Layer name

channel

Geometry

Linestring (two or more vertices)

Attributes

Table 20 Channel attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Calculation point distance	calculation_point_distance	decimal number	No	m	Maximum distance between calculation points, see Calculation point distance
Exchange type	exchange type	integer	Yes	-	Sets the 1D2D exchange type: embedded (100), isolated (101), connected (102), or double connected (105). See Exchange types.
Exchange thickness	exchange_thickness	decimal number	No	m	The thickness of the porous layer that the water needs to flow through to reach the groundwater, see Exchange between 1D and groundwater
Hydraulic conductivity in	hydraulic_conductivity_in	decimal number	No	-	Hydraulic conductivity for water flowing from the groundwater to the channel, see Exchange between 1D and groundwater
Hydraulic conductivity out	hydraulic_conductivity_out	decimal number	No	-	Hydraulic conductivity for water flowing from the channel to the groundwater, see Exchange between 1D and groundwater
Start connection node ID	connection_node_id_start	integer	Yes	-	ID of start connection node
Connection node ID end	connection_node_id_end	integer	Yes	-	ID of end connection node
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag

Notes for modellers

• Use 1D channels wisely. In many applications, schematising waterways in 2D is preferable. See Channels, culverts and pipes and Exchange types.

• All channels must have at least one Cross-section location.

Exchange type ‘embedded’

• Embedded channels add extra connections between 2D grid cells, but ignore obstacles and levees

• Make sure the embedded channel profile always lays partially below the DEM; embedded channels cannot ‘float’ above the DEM.

• Embedded channels only function when they connect several 2D grid cells, so make sure no embedded channel falls completely inside one 2D grid cell

• Do not place boundary conditions directly on embedded channels.

Exchange types ‘connected’ and ‘double connected’

For channels with exchange type ‘connected’ and ‘double connected’, 1D2D connections connect each 1D calculation point to the 2D cell it is in. Therefore, channels with these exchange types need to be in a 2D cell. Alternatively, you may use an Exchange line to customise the 1D2D connections. When using an exchange line, the channel does not need to be in 2D cells, but the exchange line needs to be in 2D cells.

Connection node

Location and ID of nodes to connect Channel, Culvert, Orifice, Weir, Pipe, Pump, or Pumps features. 1D Lateral, and 1D Boundary Condition features are also defined at connection nodes. See Laterals & 0D inflow for more information on how surfaces and dry weather flow can be mapped to a connection node.

Layer name

connection_node

Geometry

Point

Attributes

Table 21 Connection node attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Bottom level	bottom_level	decimal number	See notes	m MSL	Bottom level nodes with storage
Storage area	storage_area	decimal number	See notes	m MSL	Surface area at the bottom of the object. Adds additional storage capacity to a 1D network.
Initial water level	initial_waterlevel	decimal number	No	m above datum	Initial water level for the 1D domain
Exchange type	exchange_type	integer	No	See notes	Sets the type of 1D2D exchange: Embedded (0), Isolated (1), or Connected (2).
Exchange level	exchange_level	decimal number	No	m MSL	Exchange level for the 1D2D connection. See Notes for modellers.
Exchange thickness	exchange_thickness	decimal number	No	m	For groundwater exchange: the thickness of the (porous) manhole wall that the water needs to flow through to reach the groundwater (or v.v.), see Exchange between 1D and groundwater
Hydraulic conductivity in	hydraulic_conductivity_in	decimal number	No	-	Hydraulic conductivity for water flowing from the groundwater into the manhole, see Exchange between 1D and groundwater
Hydraulic conductivity out	hydraulic_conductivity_out	decimal number	No	-	Hydraulic conductivity for water flowing from the manhole into the groundwater, see Exchange between 1D and groundwater
Visualisation	visualisation	integer	No	m MSL	Defines how the connnection node is visualised: Connection node (NULL), Manhole (0), Outlet (1), Pump chamber (2), Infiltration manhole (3), Gully (4), or Other (99)
Manhole surface level	manhole_surface_level	decimal number	No	m MSL	Top of the manhole, e.g. street level (not used in the calculation).
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag

Notes for modellers

Connection nodes and calculation nodes

Connection nodes are not the same as calculation nodes. When 3Di generates the computational grid from the schematisation, a calculation node is created for each connection nodes, but additional 1D calculation nodes may also be created in between. See the Grid section for further details.

Bottom level

If the node has a storage area, 3Di needs a bottom level to calculate storage volumes. In many cases, this bottom level can be borrowed from adjacent objects. For example, if the node connects to a channel, that channel’s reference level can be used as bottom level for the storage node. However, if there is no adjacent object with a bottom level, the bottom level needs to be filled in. For example, a storage node between two weirs or orifices, or an embedded node without any connections to 1D objects.

Storage area

• Storage area on connection nodes is additional to the storage that is defined by the dimensions of channels, culverts and pipes. See Storage in the 1D domain for more details.

• To calculate storage volume from the storage area, the height of the water column (water level minus bottom level) needs to be known.

• For connection nodes that are not connected to channels, a storage area larger than zero is recommended.

• Connection nodes with large storage (i.e. the square root of the storage area is much larger than the width of the incoming channel) reduce the flow velocity and advective force.

Initial water level

• For calculation nodes that are added along the length of a channel, pipe, or culvert, initial water levels are linearly interpolated between connection nodes. See the Grid section for further details.

• The intial water level is stored in the simulation template and is not part of the 3Di model itself. It can be overridden when starting a new simulation, without the need to create a new revision of the schematisation.

Exchange type

It is recommended to explicitly set the exchange type to avoid confusion. If left empty, 3Di will attempt to infer the exchange type from adjacent objects. This will not be possible if the connection node is not connected to any objects with an exchange type. In that case, setting the exchange type is mandatory. See Exchange types for more information.

Exchange level

• Water can flow from the 1D domain to the 2D domain if the 1D water level exceeds the exchange level (and vice versa).

• In 1D-2D models, this setting only applies to connection nodes with calculation type ‘connected’

• In 1D-only models, the exchange level is used as the street level, above which the storage area widens to the “manhole storage area” value specified in the model settings.

• If the exchange level is not filled in, 3Di will use the DEM value at the location of the connection node, or, in case of 1D-only models, the highest top of the pipes starting or ending at this connection node.

• In 1D-2D models, the 1D-2D exchange level is the maximum of the exchange level and the 2D cell’s bottom level. See the figures below for an illustration of this.

Exchange level above lowest pixel in the 2D cell

Fig. 28 Connection node with a exchange level below the 2D cell’s lowest pixel. The 1D2D exchange level that is used in the simulation equals the 2D cell’s bottom level.

Exchange level below lowest pixel in the 2D cell

Fig. 29 Connection node with a drain level above the 2D cell’s lowest pixel. The 1D2D exchange level that is used in the simulation equals the connection node’s exchange level.

Visualisation

A connection node may be a fictional model object, or may represent a real-world object, such as a gully, manhole, outlet, or pump chamber. For the computational core, it does not matter what a connection node represents, but it may be helpful for understanding the schematisation. Correctly set the visualisation to make clear what a connection node represents.

Cross-section location

Object to define the dimensions, levels, friction and vegetation properties at a specified point along a Channel.

Layer name

cross_section_location

Geometry

Point

Attributes

Table 22 Cross-section location attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Bank level	bank_level	decimal number	Yes	m MSL	Exchange level for the 1D2D connections. Only used when exchange type is ‘connected’.
Reference level	reference_level	decimal number	Yes	m MSL	Lowest point of the cross-section
Cross-section shape	cross_section_shape	decimal number	Yes	-	Sets the cross-section shape, Cross-section shape
Cross-section width	cross_section_width	decimal number	see Cross-section shape	m	Width or diameter of the cross-section, see Cross-section shape
Cross-section height	cross_section_height	decimal number	see Cross-section shape	m	Height of the cross-section (only used for Closed rectangle cross-sections)
Cross-section table	cross_section_table	text	see Cross-section shape	m	CSV-style table of [height, width] or [Y, Z] pairs, see Cross-section shape
Friction type	friction_type	decimal number	Yes	-	See Friction type
Friction value	friction_value	decimal number	Yes	m1/2/s (Chézy) or s/m1/3 (Manning)	Friction or roughness value. This global value is superseded in case friction values are provided for each individual segment of a YZ cross-section.
Friction values	friction_values	text	No	m1/2/s (Chèzy) or s/m1/3 (Manning)	Friction value for each segment of a YZ cross-section. Comma-separated list of decimal numbers. If provided, these values override the single friction coefficient value.
Vegetation height	vegetation_height	Decimal number	Yes	m	Height of the vegetation, i.e. the length of the plant stems. This global value is superseded in case vegetation heights are provided for each individual segment of a YZ cross-section.
Vegetation stem count	vegetation_stem_count	Integer	Yes	#/m2	Density of plant stems. This global value is superseded in case vegetation stem counts are provided for each individual segment of a YZ cross-section.
Vegetation stem diameter	vegetation_stem_diameter	Decimal number	Yes	m	Mean diameter of plant stems. This global value is superseded in case vegetation stem diameters are provided for each individual segment of a YZ cross-section.
Vegetation drag coefficient	vegetation_drag_coefficient	Decimal number	Yes	-	Coefficient to linearly scale the drag that vegetation exerts on the water. The drag resulting from vegetation is different for each situation. A large share of this variation is captured by choosing the correct values for vegetation height, stem count, and stem diameter. The drag coefficient can be used to account for the other factors that affect the drag. The drag coefficient can also be used as a calibration parameter. This global value is superseded in case vegetation drag coefficients are provided for each individual segment of a YZ cross-section.
Cross-section vegetation table	cross_section_vegetation_table	Decimal number	Yes	-	CSV-style data with the “columns” vegetation_stem_densities, vegetation_stem_diameters, vegetation_heights, vegetation_drag_coefficients
Channel ID	channel_id	integer	Yes	-	Foreign key reference to an ID in the Channel table

Notes for modellers

• A cross-section location should be placed on top of a channel vertex that is not the start or end vertex

• If the channel calculation point distance is smaller than the distance between cross section locations, values in the cross section locations along the channel are interpolated, see Calculation point distance.

• If there are multiple cross-section locations between two calculation nodes (not connection nodes), only the first cross-section location is used.

• For YZ cross-sections, friction coefficients and vegetation parameters can be defined for each individual segment of the cross-section. A segment is defined as the domain between two YZ coordinates; so if the YZ cross-section is defined by 10 YZ coordinates, the cross-section will have 9 segments. This option is only available when using friction types Manning with conveyance or Chézy with conveyance.

• When separate values are defined for each segment, the single value will be ignored.

• For vegetation, either all parameter values must be defined as a single value, or all parameter values must be defined for each segment in the cross-section vegetation table.

• For the cross-section shapes Tabulated rectangle, Tabulated trapezium and YZ, the cross-section shape can be added or edited in the cross-section location attribute table. In the form view, this can be done by filling out the table. In the table view, a CSV-style table can be pasted into the cross_section_table field.

Reference level

This is the bed level of the channel and the reference level for the cross-section. For example, if the reference level is 12.0 m MSL and the cross-section a tabulated rectangle with a width of 5 m at height 0, this means that the channel is 5 m wide at 12.0 m MSL.

Cross-section shape

The following shapes are supported:

Table 23 Cross-section shapes

Shape	Value	Instructions
Closed rectangle	0	Specify cross-section height and cross-section width
Open rectangle	1	Specify cross-section width
Circle	2	Specify cross-section width (i.e., diameter)
Egg	3	Specify cross-section width. Height will be 1.5 * width.
Tabulated rectangle	5	Fill cross-section table as CSV-style table of height, width pairs
Tabulated trapezium	6	Fill cross-section table as CSV-style table of height, width pairs
YZ	7	Fill cross-section table as CSV-style table of Y, Z pairs
Inverted egg	8	Specify cross-section width. Height will be 1.5 * width.

Friction type

This attribute sets the friction type to:

• Chézy (1)

• Manning (2)

• Chézy with conveyance (3)

• Manning with conveyance (4)

Using the friction types with conveyance is advised for open Tabulated or YZ cross-sections, in case there is a significant variation of the water depths across the cross-section, for instance, in a scenario with overflowing floodplains.

Culvert

Culverts are used to schematise pipes in open water systems.

In contrast to an Orifice, the flow behaviour in a culvert is assumed to be determined by shape and much less dominated by entrance losses. Culverts can be used for longer sections of pipe-like structures and do not have to be straight. Shorter, straight culverts are best schematised as an Orifice.

Layer name

culvert

Geometry

Linestring (two or more vertices)

Attributes

Table 24 Culvert attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Discharge coefficient positive	discharge_coefficient_positive	decimal_number	Yes	-	Discharge in the positive direction is multiplied by this value
Discharge coefficient negative	discharge_coefficient_negative	decimal_number	Yes	-	Discharge in the negative direction is multiplied by this value
Calculation point distance	calculation_point_distance	decimal number	No	m	Maximum distance between calculation points, see Calculation point distance
Exchange type	exchange_type	integer	Yes	-	Sets the 1D2D exchange type: Embedded (100), Isolated (101), Connected (102), or Double connected (105). See Exchange types.
Material	material_id	integer	No	-	Foreign key reference to an ID in the Material table, see Material, friction type and friction value
Friction type	friction_type	decimal number	Yes	-	Sets the friction type to Chézy (1) or Manning (2)
Friction value	friction_value	decimal number	Yes	m1/2/s (Chézy) or s/m1/3 (Manning)	Friction or roughness value
Invert level start	invert_level_start	decimal number	Yes	m MSL	Level of lowest point on the inside at the start of the culvert
Invert level end	invert_level_end	decimal number	Yes	m MSL	Level of lowest point on the inside at the end of the culvert
Cross-section shape	cross_section_shape	decimal number	Yes	integer	Sets the cross-section shape, Cross-section shape
Cross-section width	cross_section_width	decimal number	see Cross-section shape	integer	Width or diameter of the cross-section, see Cross-section shape
Cross-section height	cross_section_height	decimal number	see Cross-section shape	m	Height of the cross-section (only used for Closed rectangle cross-sections)
Cross-section table	cross_section_table	text	see Cross-section shape	m	CSV-style table of [height, width] or [Y, Z] pairs, see Cross-section shape
Connection node ID start	connection_node_id_start	integer	Yes	-	ID of start connection node
Connection node ID end	connection_node_id_end	integer	Yes	-	ID of end connection node
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag

Notes for modellers

The cross-section describes the inside of the culvert. If you only know the outer dimensions, you have to discount the wall thickness.

Discharge coefficients

The discharge is multiplied by this value. The energy loss caused by the change in flow velocity at the entrance and exit are accounted for by 3Di. The discharge coefficients can be used to account for any additional energy loss. ‘Positive’ applies to flow in the drawing direction of the structure (from start node to end node); ‘negative’ applies to flow in the opposite direction.

Material, friction type and friction value

The Material table lets you define materials with a friction type and friction value. In the attribute form of the culvert, you can either fill in the material ID to use the friction type and value of that material, or fill in the friction type an value directly. If you fill in both the material ID and the friction type and friction value, the latter will be used.

Material

Material for which you want to define a friction type and friction value. Can be used to set the friction data for Culvert, Pipe, Orifice, or Weir

Layer name

material

Geometry

No geometry

Attributes

Table 25 Material attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Description	description	text	No	-	Name of the material
Friction type	friction_type	decimal number	Yes	-	Sets the friction type to Chézy (1) or Manning (2)
Friction coefficient	friction_coefficient	decimal number	Yes	m1/2/s (Chézy) or s/m1/3 (Manning)	Friction or roughness value

Orifice

An orifice can be used to schematise hydraulic structures like gates, bridges, or culverts. It can be used in open water systems as well as in sewerage systems.

An orifice is commonly used to schematise structures that are closed at the top of the cross-section, whereas the Weir is commonly used for structures that are open at the top. However, both types of cross-sections can be used for either structure, and 3Di uses them in the calculation in the same way. See Weirs and Orifices for further details.

Layer name

orifice

Geometry

Linestring (exactly two vertices)

Attributes

Table 26 Orifice attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Crest type	crest_type	integer	Yes	-	Sets the crest type: broad-crested (3) or short-crested (4)
Discharge coefficient positive	discharge_coefficient_positive	decimal_number	Yes	-	Discharge in the positive direction is multiplied by this value
Discharge coefficient negative	discharge_coefficient_negative	decimal_number	Yes	-	Discharge in the negative direction is multiplied by this value
Material	material_id	integer	See Material, friction type and friction value	-	Foreign key reference to an ID in the Material table.
Friction type	friction_type	decimal number	See Material, friction type and friction value	-	Sets the friction type to Chézy (1) or Manning (2)
Friction value	friction_value	decimal number	See Material, friction type and friction value	m1/2/s (Chézy) or s/m1/3 (Manning)	Friction or roughness value
Crest level	crest_level	decimal number	Yes	m MSL	Lowest point of the cross-section.
Cross-section shape	cross_section_shape	decimal number	Yes	-	Sets the cross-section shape, Cross-section shape
Cross-section width	cross_section_width	decimal number	see Cross-section shape	m	Width or diameter of the cross-section, see Cross-section shape
Cross-section height	cross_section_height	decimal number	see Cross-section shape	m	Height of the cross-section (only used for Closed rectangle cross-sections)
Cross-section table	cross_section_table	text	see Cross-section shape	m	CSV-style table of [height, width] or [Y, Z] pairs, see Cross-section shape
Sewerage	sewerage	boolean	Yes	-	Indicates if the structure is part of the sewerage system (True) or not (False)
Connection node ID start	connection_node_id_start	integer	Yes	-	ID of the start connection node
Connection node ID end	connection_node_id_end	integer	Yes	-	ID of the end connection node
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag

Notes for modellers

In the computational grid, an orifice will always be represented by a single flowline. Therefore, orifices do not have a calculation point distance and exchange type.

Crest level

This is the reference level for the cross-section. For example, if the crest level is 12.0 m and the cross-section a circle with a diameter of 0.5 m, the opening will start at 12.0 m and end at 12.5 m

Discharge coefficients

The discharge is multiplied by this value. The energy loss caused by the change in flow velocity at the entrance and exit are accounted for by 3Di. The discharge coefficients can be used to account for any additional energy loss. ‘Positive’ applies to flow in the drawing direction of the structure (from start node to end node); ‘negative’ applies to flow in the opposite direction.

Material, friction type and friction value

Only orifices with crest type Broad-crested need a friction type and friction value. Short-crested orifices do not need this.

The Material table lets you define materials with a friction type and friction value. In the attribute form of the orifice, you can either fill in the material ID to use the friction type and value of that material, or fill in the friction type an value directly. If you fill in both the material ID and the friction type and friction value, the latter will be used.

Pipe

Pipe in a sewerage system.

Layer name

pipe

Geometry

Linestring (two or more vertices)

Attributes

Table 27 Pipe attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Calculation point distance	calculation_point_distance	decimal number	No	m	Maximum distance between calculation points, see Calculation point distance
Exchange type	exchange_type	integer	Yes	-	Sets the 1D2D exchange type: Embedded (0), Isolated (1), or Connected (2). See Exchange types.
Material	material_id	integer	No	-	Foreign key reference to an ID in the Material table, see Material, friction type and friction value
Friction type	friction_type	decimal number	See Material, friction type and friction value	-	Sets the friction type to Chézy (1) or Manning (2)
Friction value	friction_value	decimal number	See Material, friction type and friction value	m1/2/s (Chézy) or s/m1/3 (Manning)	Friction or roughness value
Invert level start	invert_level_start	decimal number	Yes	m MSL	Level of lowest point on the inside at the start of the pipe
Invert level end	invert_level_end	decimal number	Yes	m MSL	Level of lowest point on the inside at the end of the pipe
Cross-section shape	cross_section_shape	decimal number	Yes	integer	Sets the cross-section shape, Cross-section shape
Cross-section width	cross_section_width	decimal number	See Cross-section shape	integer	Width or diameter of the cross-section, see Cross-section shape
Cross-section height	cross_section_height	decimal number	See Cross-section shape	m	Height of the cross-section (only used for Closed rectangle cross-sections)
Cross-section table	cross_section_table	text	See Cross-section shape	m	CSV-style table of [height, width] or [Y, Z] pairs, see Cross-section shape
Exchange thickness	exchange_thickness	decimal number	No	m	The thickness of the (porous) pipe wall that the water needs to flow through to reach the groundwater (or v.v.), see Exchange between 1D and groundwater
Hydraulic conductivity in	hydraulic_conductivity_in	decimal number	No	-	Hydraulic conductivity for water flowing from the groundwater into the pipe, see Exchange between 1D and groundwater
Hydraulic conductivity out	hydraulic_conductivity_out	decimal number	No	-	Hydraulic conductivity for water flowing from the pipe to the groundwater, see Exchange between 1D and groundwater
Sewerage type	sewerage_type	integer	Yes	-	Function of the pipe in the sewerage system. Used for visualisation and administrative purposes only. See Notes for modellers.
Connection node ID start	connection_node_id_start	integer	Yes	-	ID of start connection node
Connection node ID end	connection_node_id_end	integer	Yes	-	ID of start connection node
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag

Notes for modellers

• The cross-section describes the inside of the pipe. If you only know the outer dimensions, you have to discount the wall thickness.

• To draw a single pipe, the geometry must have exactly 2 vertices. A line with more than 2 vertices will be split into several pipes.

Adding a pipe trajectory

When you digitize (draw) a pipe feature with more than two vertices, each vertex will be converted into a connection node plus manhole, connected by pipes. If you digitize a pipe that connects existing manholes, the pipe(s) will use the manholes’ bottom levels as their invert levels and automatically refer to the correct the connection nodes. Therefore, the quickest way to digitize a trajectory of multiple pipes is to first digitize the manholes, fill in the bottom levels, and then draw the pipe trajectory over these manholes by adding a vertex at each of the manholes.

Material, friction type and friction value

The Material table lets you define materials with a friction type and friction value. In the attribute form of the pipe, you can either fill in the material ID to use the friction type and value of that material, or fill in the friction type and value directly. If you fill in both the material ID and the friction type and friction value, the latter will be used.

Sewerage type

The following types are supported: - Combined sewer (0) - Storm drain (1) - Sanitary sewer (2) - Transport (3) - Spillway (4) - Syphon (5) - Storage (6) - Storage and settlement tank (7)

Groundwater exchange

To let the pipe exchange with groundwater, specify the Exchange thickness, Hydraulic conductivity in, and Hydraulic conductivity out. This is independent from the exchange type (embedded/isolated/connected), so you can also schematise a pipe that does not exchange with the surface water domain (exchange type is isolated), but does exchange with the groundwater domain.

Pump

Structure that pumps water out of the model domain, or, when combined with a Pump map, to another connection node within the model domain. See Pumps for details on how pumps work in 3Di.

Layer name

pump

Geometry

Point

Attributes

Table 28 Pump attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Capacity	capacity	decimal number	Yes	L/s	Pump capacity
Start level	start_level	decimal number	Yes	m MSL	Pump switches on when the water level exceeds this level
Lower stop level	lower_stop_level	decimal number	Yes	m MSL	Pump switches off when the water level becomes lower than this level
Upper stop level	upper_stop_level	decimal number	Yes	m MSL	Pump switches off when the water level exceeds this level
Type	type	integer	Yes	-	Sets whether pump reacts to water level at: suction side (1) or delivery side (2)
Sewerage	sewerage	boolean	Yes	-	Indicates if the pump is part of the sewerage system (True) or not (False)
Connection node ID	connection_node_id	integer	Yes	-	ID of connection node on which the pumpstation is placed

Notes for modellers

• Multiple pumps may be defined for the same connection node. If their active ranges (start/stop level) overlap, they may pump at the same time.

Pump map

Mapping object to define to which connection node a pump should pump.

Geometry

Linestring (exactly two vertices)

Attributes

Table 29 Pump map attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Pump ID	pump_id	integer	Yes	-	Foreign key reference to the ID of a Pump
Connection node ID end	connection_node_end_id	integer	Yes	-	ID of connection node to which the water is pumped

Notes for modellers

• Each pump can be mapped only once.

Weir

Overflow structure, used to control the water level. It can be used in open water systems as well as sewerage systems.

A weir is commonly used to schematise structures with open cross sections, whereas the Orifice is commonly used for structures that are closed at the top. However, both types of cross-sections can be used for either structure, and 3Di uses them in the calculation in the same way. See Weirs and Orifices for further details.

Layer name

weir

Geometry

Linestring (exactly two vertices)

Attributes

Table 30 Weir attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Crest type	crest_type	integer	Yes	-	Sets the crest type: broad-crested (3) or short-crested (4)
Discharge coefficient positive	discharge_coefficient_positive	decimal_number	Yes	-	Discharge in the positive direction is multiplied by this value
Discharge coefficient negative	discharge_coefficient_negative	decimal_number	Yes	-	Discharge in the negative direction is multiplied by this value
Material	material_id	integer	See Material, friction type and friction value	-	Foreign key reference to an ID in the Material table.
Friction type	friction_type	decimal number	See Material, friction type and friction value	-	Sets the friction type to Chézy (1) or Manning (2)
Friction value	friction_value	decimal number	See Material, friction type and friction value	m1/2/s (Chézy) or s/m1/3 (Manning)	Friction or roughness value
Crest level	crest_level	decimal number	Yes	m MSL	Lowest point of the cross-section.
Cross-section shape	cross_section_shape	decimal number	Yes	-	Sets the cross-section shape, Cross-section shape
Cross-section width	cross_section_width	decimal number	see Cross-section shape	m	Width or diameter of the cross-section, see Cross-section shape
Cross-section height	cross_section_height	decimal number	see Cross-section shape	m	Height of the cross-section (only used for Closed rectangle cross-sections)
Cross-section table	cross_section_table	text	see Cross-section shape	m	CSV-style table of [height, width] or [Y, Z] pairs, see Cross-section shape
Sewerage	sewerage	boolean	Yes	-	Indicates if the structure is part of the sewerage system (True) or not (False)
Connection node ID start	connection_node_id_start	integer	Yes	-	ID of the start connection node
Connection node ID end	connection_node_id_end	integer	Yes	-	ID of the end connection node
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag

Notes for the modeller

In the computational grid, a weir will always be represented by a single flowline. Therefore, weirs do not have a calculation point distance and exchange type. The exchange type of the start and end nodes is determined by the channels, culverts, manholes, and pipes connected to them.

Crest level

This is the reference level for the cross-section. For example, if the crest level is 12.0 m and the cross-section a circle with a diameter of 0.5 m, the opening will start at 12.0 m and end at 12.5 m

Discharge coefficients

The discharge is multiplied by this value. The energy loss caused by the change in flow velocity at the entrance and exit are accounted for by 3Di. The discharge coefficients can be used to account for any additional energy loss. ‘Positive’ applies to flow in the drawing direction of the structure (from start node to end node); ‘negative’ applies to flow in the opposite direction.

Material, friction type and friction value

Only weirs with crest type Broad-crested need a friction type and friction value. Short-crested weirs do not need this.

The Material table lets you define materials with a friction type and friction value. In the attribute form of the orifice, you can either fill in the material ID to use the friction type and value of that material, or fill in the friction type an value directly. If you fill in both the material ID and the friction type and friction value, the latter will be used.

1D Wind shielding

Wind shielding reduces the wind shear on open water.

Layer name

windshielding_1d

Geometry

Point

Attributes

Table 31 1D Wind shielding attributes

Attribute alias	Field name	Type	Mandatory	Units	Description
ID	id	integer	Yes	-	Unique identifier
Code	code	text	No	-	Name field, no constraints
Display name	display_name	text	No	-	Name field, no constraints
Channel ID	channel_id	integer	No	-	ID of the channel
North	north	decimal number	No	-	The amount of wind being shielded from the north.
North-east	northeast	decimal number	No	-	The amount of wind being shielded from the north-east .
East	east	decimal number	No	-	The amount of wind being shielded from the east.
South-east	southeast	decimal number	No	-	The amount of wind being shielded from the south-east.
South	south	decimal number	No	-	The amount of wind being shielded from the south.
South-west	southwest	decimal number	No	-	The amount of wind being shielded from the south-west.
West	west	decimal number	No	-	The amount of wind being shielded from the west.
North-west	northwest	decimal number	No	-	The amount of wind being shielded from the north-west.
Tags	tags	text	No	-	Comma-separated list of foreign key references to ID’s in Tag