About modelling 2D objects

00:03

Some objects are specific to the 2D domain.

00:08

These 2D objects are used to bring flow to the 2D mesh or represent structures such as culverts and bridges.

00:16

The calculations for these 2D objects are maintained within the 2D engine.

00:25

so reducing the calculations where appropriate can help give you the best user experience throughout the lifecycle of your model.

00:33

There is a lot of flexibility in ICM for generating flows, either externally through event files, or internally using direct rainfall or subcatchments.

00:42

A disadvantage of Inflow events is that you have to set up each simulation individually.

00:49

A more streamlined approach for a network can be to model the upstream rural catchments using large subcatchments,

00:56

which discharge into point or line sources at the upstream extent of your meshes.

01:01

This can significantly cut down the size of your 2D zone,

01:04

compared with undertaking direct rainfall modelling on the entire catchment model,

01:08

and you still have the option of using rainfall events to trigger the creation of multiple simulations.

01:15

Here is a high-level overview of the 2D objects available in InfoWorks ICM:

01:28

Inflow associated with the point source discharges to the 2D mesh element in which the point is located.

01:34

Similar to 2D point source objects, 2D Line Source objects are used to define the location of a flow-time boundary line within a 2D zone.

01:44

Inflow associated with the line source discharges into the 2D mesh elements adjacent to the line.

01:58

allowing flow to be transferred between two areas of a 2D zone.

02:02

Conduit (2D) links are intended to represent a drainage structure such as a culvert, which may be located beneath a road.

02:10

This allows you to maintain the road deck in your mesh, but represent the flow through the culvert underneath.

02:16

When a 2D conduit is connected to a Connect 2D type of node, flow calculation depends on the type of connection:

02:24

Closed - No flow through the edge—for example, at the upstream edge of the 2D conduit.

02:31

Lost - Any flow through the edge is lost.

02:36

The 2D engine assumes uniform flow conditions at the edge.

02:46

The hydraulic variables in the 2D element are used as a boundary condition in the 2D conduit.

02:52

Break - Used to connect two 2D conduits.

02:56

Flow is calculated as if the two 2D conduits are joined together and the break type of the Connect 2D node does not have any storage.

03:04

Linear Drainage (2D) is a type of 2D conduit that represents a linear gully, such as a slot drain,

03:11

which is connected vertically to the 2D surface.

03:14

This type of 1D-2D linear connection can be used where the drain slot or trench

03:19

is much longer than the equivalent face length of the 2D element area defined on 2D zones.

03:25

Such types of drainage systems are used on roads and large infrastructures, such as airports.

03:30

This functionality could also be used for detailed drainage site projects, where the 2D modelling resolution is 100m2 or less.

03:39

Base Linear Structure (2D) objects are line objects used as part of the 2D mesh generation process.

03:45

The lines represent structures, such as a wall with a specified porosity and height, used in the 2D simulation process.

03:54

The following types of structure can be modelled:

03:57

Walls, weirs—thin plate weir or broad crested weir—and user-controlled,

04:03

for which flow through the structure is controlled by a user-defined head-discharge curve.

04:08

Sluices and bridges along the length of the linear structure can be modelled by associating Sluice Linear Structure (2D)

04:14

and Bridge Linear Structure (2D) objects with the base linear structure.

04:20

Sluice Linear Structure (2D) objects are used to define sluice gate dimensions, coefficients,

04:26

and the location of sluices within 2D base linear structures.

04:38

It is not necessary to digitize the objects, as they assume the geometry length of the referenced 2D base linear structure.

04:45

Bridge Linear Structure (2D) objects are used to define bridge dimensions, coefficients,

04:50

and the location of bridges within 2D base linear structures.

04:55

You may be reluctant to use the bridge linear structure, as it appears only as a line and does not conceptualize the bridge depth.

05:03

However, the bridge linear structure may only start to become hydraulically unrepresentative

05:08

where the bridge depth is significantly greater than the distance between element centroids.

05:13

In this case, it should probably be modelled as a conduit (2D) link instead.

05:18

It is possible to adjust the geometry of objects that interact with the 2D domain.

05:23

Most likely, these would be used to represent a collapse or breach.

05:28

A time-varying level can be defined for the following objects:

05:32

River reaches (left and right bank)

05:36

Inline banks (used as a 1D-2D link)

05:40

Base linear structures (2D)

05:43

A breach is modelled by using Real Time Control (RTC) definitions

05:47

to specify vertical movement of bank/linear structure point vertices with respect to time.

05:53

At each run timestep, ICM evaluates RTC definitions

05:58

and uses them to set the current elevation of any points with an RTC definition specified.

Video transcript

00:03

Some objects are specific to the 2D domain.

00:08

These 2D objects are used to bring flow to the 2D mesh or represent structures such as culverts and bridges.

00:16

The calculations for these 2D objects are maintained within the 2D engine.

00:25

so reducing the calculations where appropriate can help give you the best user experience throughout the lifecycle of your model.

00:33

There is a lot of flexibility in ICM for generating flows, either externally through event files, or internally using direct rainfall or subcatchments.

00:42

A disadvantage of Inflow events is that you have to set up each simulation individually.

00:49

A more streamlined approach for a network can be to model the upstream rural catchments using large subcatchments,

00:56

which discharge into point or line sources at the upstream extent of your meshes.

01:01

This can significantly cut down the size of your 2D zone,

01:04

compared with undertaking direct rainfall modelling on the entire catchment model,

01:08

and you still have the option of using rainfall events to trigger the creation of multiple simulations.

01:15

Here is a high-level overview of the 2D objects available in InfoWorks ICM:

01:28

Inflow associated with the point source discharges to the 2D mesh element in which the point is located.

01:34

Similar to 2D point source objects, 2D Line Source objects are used to define the location of a flow-time boundary line within a 2D zone.

01:44

Inflow associated with the line source discharges into the 2D mesh elements adjacent to the line.

01:58

allowing flow to be transferred between two areas of a 2D zone.

02:02

Conduit (2D) links are intended to represent a drainage structure such as a culvert, which may be located beneath a road.

02:10

This allows you to maintain the road deck in your mesh, but represent the flow through the culvert underneath.

02:16

When a 2D conduit is connected to a Connect 2D type of node, flow calculation depends on the type of connection:

02:24

Closed - No flow through the edge—for example, at the upstream edge of the 2D conduit.

02:31

Lost - Any flow through the edge is lost.

02:36

The 2D engine assumes uniform flow conditions at the edge.

02:46

The hydraulic variables in the 2D element are used as a boundary condition in the 2D conduit.

02:52

Break - Used to connect two 2D conduits.

02:56

Flow is calculated as if the two 2D conduits are joined together and the break type of the Connect 2D node does not have any storage.

03:04

Linear Drainage (2D) is a type of 2D conduit that represents a linear gully, such as a slot drain,

03:11

which is connected vertically to the 2D surface.

03:14

This type of 1D-2D linear connection can be used where the drain slot or trench

03:19

is much longer than the equivalent face length of the 2D element area defined on 2D zones.

03:25

Such types of drainage systems are used on roads and large infrastructures, such as airports.

03:30

This functionality could also be used for detailed drainage site projects, where the 2D modelling resolution is 100m2 or less.

03:39

Base Linear Structure (2D) objects are line objects used as part of the 2D mesh generation process.

03:45

The lines represent structures, such as a wall with a specified porosity and height, used in the 2D simulation process.

03:54

The following types of structure can be modelled:

03:57

Walls, weirs—thin plate weir or broad crested weir—and user-controlled,

04:03

for which flow through the structure is controlled by a user-defined head-discharge curve.

04:08

Sluices and bridges along the length of the linear structure can be modelled by associating Sluice Linear Structure (2D)

04:14

and Bridge Linear Structure (2D) objects with the base linear structure.

04:20

Sluice Linear Structure (2D) objects are used to define sluice gate dimensions, coefficients,

04:26

and the location of sluices within 2D base linear structures.

04:38

It is not necessary to digitize the objects, as they assume the geometry length of the referenced 2D base linear structure.

04:45

Bridge Linear Structure (2D) objects are used to define bridge dimensions, coefficients,

04:50

and the location of bridges within 2D base linear structures.

04:55

You may be reluctant to use the bridge linear structure, as it appears only as a line and does not conceptualize the bridge depth.

05:03

However, the bridge linear structure may only start to become hydraulically unrepresentative

05:08

where the bridge depth is significantly greater than the distance between element centroids.

05:13

In this case, it should probably be modelled as a conduit (2D) link instead.

05:18

It is possible to adjust the geometry of objects that interact with the 2D domain.

05:23

Most likely, these would be used to represent a collapse or breach.

05:28

A time-varying level can be defined for the following objects:

05:32

River reaches (left and right bank)

05:36

Inline banks (used as a 1D-2D link)

05:40

Base linear structures (2D)

05:43

A breach is modelled by using Real Time Control (RTC) definitions

05:47

to specify vertical movement of bank/linear structure point vertices with respect to time.

05:53

At each run timestep, ICM evaluates RTC definitions

05:58

and uses them to set the current elevation of any points with an RTC definition specified.

Video quiz

Required for course completion

What type of 2D object represents a linear gully, such as a slot drain?

(Select one)
Select an answer

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2D Objects:

Specific to 2D domain and used to bring flow to 2D mesh or represent structures, such as culverts and bridges.

Calculations for 2D objects maintained within 2D engine.

 

2D Calculations:

Can be computationally expensive, so reducing ensures best user experience.

ICM offers flexibility for generating flows, either externally through event files, or internally using direct rainfall or subcatchments.

Disadvantage of Inflow events is having to set up simulations individually.

More streamlined network approach is to model upstream rural catchments using large subcatchments, which discharge into point or line sources at upstream extent of meshes.

  • Can significantly cut down size of 2D zone.
  • Can still use rainfall events to trigger simulations

 

2D Point/Line Source Objects:

2D Point Source:

  • Used to define location of flow-time boundary point within 2D zone.
  • Associated inflow discharges to 2D mesh element in which point is located.

2D Line Source:

  • Similar to 2D point source objects.
  • Used to define the location of a flow-time boundary line within a 2D zone.
  • Associated inflow discharges into 2D mesh elements adjacent to line.

 

2D Conduits:

Can be used in 2D simulation to introduce unidimensional hydraulic structures directly in 2D engine.

Allow transfer of flow between two areas of 2D zone.

Intended to represent a drainage structure, such as a culvert beneath a road. This allows you to maintain road deck in mesh, but represent flow through culvert underneath.

When connected to a Connect 2D node, flow calculation depends on connection type:

  • Closed - No flow through edge—for example, at upstream edge of 2D conduit.
  • Lost - Any flow through edge is lost. 2D engine assumes uniform flow conditions at edge.
  • 2D - Indicates connection to element in 2D surface. Hydraulic variables in 2D element used as boundary condition in 2D conduit.
  • Break - Used to connect two 2D conduits. Flow calculated as if two 2D conduits are joined and assumes the break type of Connect 2D node does not have storage.

 

Linear Drainage (2D):

Type of 2D conduit that represents linear gully, such as a slot drain connected vertically to a 2D surface.

A visual representation of a linear gully with a slot drain in a 2D surface.

1D-2D linear connection that can be used where drain slot or trench is much longer than equivalent face length of 2D element area defined on 2D zones.

Used on roads and large infrastructures, such as airports.

Can also be used for detailed drainage site projects, where 2D modelling resolution is 100m2 or less.

 

Base Linear Structure (2D):

Line objects used as part of 2D mesh generation process.

Represent structures, such as a wall with specified porosity and height, used in 2D simulation process.

Structure types that can be modelled:

  • Walls
  • Weirs—thin plate weir or broad crested weir
  • User-controlled, with flow through structure controlled by user-defined head-discharge curve

Sluices and bridges along the length of the linear structure can be modelled by associating Sluice Linear Structure (2D) and Bridge Linear Structure (2D) objects with the base linear structure.

The Properties window for a Base linear structure (2D) object, zoomed in to the definition settings, including Structure type, Level, and Porosity.

 

Sluice Linear Structure (2D):

Used to define sluice gate dimensions, coefficients, and location of sluices within 2D base linear structures.

Can be created in Lines Grid or digitized directly on GeoPlan as line objects.

Assume geometry length of referenced 2D base linear structure, so digitizing not necessary.

A section data window showing an example of a sluice linear structure.

 

Bridge Linear Structure (2D):

Used to define bridge dimensions, coefficients, and location of bridges within 2D base linear structures.

Appears as a line and does not conceptualize bridge depth, so there is reluctance to use it.

May only become hydraulically unrepresentative with bridge depth significantly greater than distance between element centroids. In this case, can be modelled as conduit (2D) link instead.

A section data window for a Bridge linear structure, with a data grid that includes columns for Offset, X and Y coordinates, Opening height, and Deck; and below, a graph version of the same data, showing Elevation (Y) and Offset (X).

 

Time-varying Geometry:

Geometry of objects interacting with 2D domain can be adjusted.

Most likely used to represent collapse or breach.

Can define time-varying level for:

  • River reaches—left and right bank
  • Inline banks—used as 1D-2D link
  • Base linear structures (2D)

From the RTC dialog, an arrow connects the RTC1 item with the RTC definition column in the Base linear structure section data window, which appears below it.

Breach can be modelled using Real Time Control (RTC) definitions to specify vertical movement of bank/linear structure point vertices with respect to time.

At each run timestep, ICM evaluates RTC definitions and uses them to set current elevation of any points with RTC definition specified.

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