2D Zone Data Fields (InfoWorks)

2D zones are used as part of the mesh generation process carried out when undertaking 2D Modelling. They can be used to define areas of particular interest for which more detailed analysis is required.

Note: To view all data relating to this object, use the Object Properties Window. These data fields are read-only in ICMLive Operator Client. Network objects are configured in InfoWorks ICM Ultimate and ICMLive Configuration Manager. Please refer to the InfoWorks ICM help for more details.

The following describes all the data which can be used to define a 2D zone. For details of results fields, see the 2D Zone Results Data Fields topic.

Fields that are common to the majority of objects can be found in the Common Fields topic.

2D Zone Data

Database Table Name: hw_2d_zone

Field Name	Description	Database Field	Data Type	Size	Units	Precision	Default	Error Lower Limit	Error Upper Limit	Warning Lower Limit	Warning Upper Limit
ID	The name of the zone.	zone_id	Text	64		0
Area	Zone area. Default value calculated from polygon geometry.	area	Double		CA	3
Maximum triangle area	A measure of mesh resolution used when creating a 2D mesh. Maximum allowable triangle area for areas in the 2D zone that are not in a mesh zone.	max_triangle_area	Double		NA	3	100.0 m2	0.001
Minimum element area	Minimum mesh element area used for calculating results. Mesh elements with area less than the minimum area specified, will be aggregated with adjoining elements, until the minimum area is met. This is done for the purpose of calculating results in order to improve simulation stability and run time. Mesh elements will not be aggregated across wall objects or Mesh zone boundaries. The minimum element area is also applied to limit the extent to which triangles are subdivided during terrain-sensitive meshing.	min_mesh_element_area	Double		NA	3	25.0 m2	0.001
Mesh generation	The type of mesh generation. Choices are: Classic - the classic meshing approach that has been present in ICMLive Operator Client since it was first released. Clip meshing - A meshing approach that makes use of primary and secondary meshing phases. It is particularly suited to models with complex geometry and objects that may be approximately coincident. See 2D Mesh Generation Methodology for further information about these two meshing methods. The default meshing method is Clip meshing unless overwritten by a User Defined Default.	mesh_generation	Text	20		0	User Defined Default.
Boundary type	Boundary condition for the 2D zone. (In any boundary case where water is allowed to flow out of the 2D zone, the water volume that has flowed out of the 2D zone is recorded in the log file to check mass conservation.) Note that a Porous Wall, Porous Polygon, Base Linear Structure, 2D Boundary or Building collinear with the boundary of the 2D zone, will override the boundary condition of the 2D zone along the coincident portion of the boundary. In the case of a porous wall, porous polygon or base linear structure coincident portions of the wall/polygon are considered infinitely high, regardless of any crest level specified. Database Value Description Vertical wall The boundary of the 2D zone is considered to be an impermeable infinitely high barrier. Water cannot flow out of, or into, the 2D zone. Critical condition If the level in the boundary element of the 2D zone is above the boundary face level, flow out of the 2D zone will be calculated using a broad crested weir equation without energy loss. If the level in the boundary element is below the boundary face level, the boundary is considered to be a vertical impervious wall. Water cannot flow into the 2D zone. Supercritical condition If the flow in the boundary element is supercritical (Froude > 1) and directed outside of the 2D zone, then the flow at the boundary face will be considered supercritical and calculated using the boundary element depth and velocity, regardless of the boundary face level. If the conditions of the flow are not supercritical, or the flow is going into the 2D zone, the boundary face will be considered as a vertical wall. This situation is useful in areas where the user knows that the flow is flowing out of the 2D zone without any effects on the 2D zone. Water cannot flow into the 2D zone. Dry The boundary of the 2D zone is considered to be surrounded by a bottomless pit. Water that reaches the edge of the 2D zone will flow out of the zone and will be lost from the simulation. Water cannot flow into the 2D zone. Normal condition It is assumed that slope balances friction forces (normal flow). Depth and velocity are kept constant when water reaches the boundary, so water can flow out without losses.	boundary_type	Text	80		0	Vertical Wall
Terrain-sensitive meshing	If checked, terrain-sensitive meshing is applied during the mesh generation process. The Maximum height variation field must be specified. See Terrain-sensitive meshing for more details.	terrain_sensitive_mesh	Boolean
Maximum height variation	Enabled when Terrain-sensitive meshing is checked. The maximum height variation that is permitted within a single triangle. Triangles with a height variation greater than this will be split provided this would not result in a triangle smaller than the Minimum element area.	max_height_variation	Double		L	3	1.0	0.001
Minimum angle	Minimum allowable angle between triangle vertices when creating a 2D mesh.	minimum_angle	Double		ANGLE	2	25.0	0.01	35
Roughness (Manning's n)	Manning roughness (n), used when creating a 2D mesh. The roughness value assigned to mesh elements in areas in the 2D zone that are not in a roughness zone. This field is automatically disabled if a Roughness definition object is selected in the Roughness definition field.	roughness	Double			4	0.0125	0
Roughness definition	The name of the Roughness definition associated with the 2D zone. Any Roughness definitions already specified can be selected from the dropdown. Alternatively, a new one can be added or an existing one modified using the button located to the left of the field. This displays the non-visual object menu, from which you can select the appropriate option.	roughness_definition_id	Text	64
Apply rainfall etc directly to mesh elements	If checked, Rainfall profiles and their corresponding Evaporation profiles are applied to 2D mesh elements in the zone. Note: If 2D meshes and subcatchments overlap, rainfall will be applied to both subcatchment and 2D mesh independently by default. To prevent applying rainfall twice in subcatchment areas, set the Apply rainfall etc field to outside subcatchments.	apply_rainfall_directly	Boolean			0	0
Apply rainfall etc	Enabled when Apply rainfall etc directly to mesh elements is selected. Used to define whether application of rainfall and evaporation will be applied to the entire mesh, or outside of subcatchments only. Database Value Description everywhere Rainfall and evaporation will be applied to all mesh elements in the 2D zone outside subcatchments Outside subcatchments (outside subcatchments and buildings) Rainfall and evaporation will only be applied to those mesh elements whose centroids are not inside a subcatchment or building boundary. Use this option to prevent rainfall being applied twice to subcatchment or building areas.	apply_rainfall_subcatch	Text	80		0	everywhere
Rainfall profile	The name of the rainfall profile applied to the mesh elements in this polygon. Each profile within a Rainfall Event has a unique name. You must set a value in this field, or set the field flag to #D to use the User Defined Default. If the field does not contain a valid rainfall profile ID, the following action is taken when you run a simulation: If the Rainfall Event contains a single profile, this profile is applied in the simulation. This makes the assumption that if there is only one profile, you will want to apply it to the whole model. If the Rainfall Event contains more than one profile, ICMLive Operator Client uses the first profile in the event. A warning is included in the simulation log file. When using a Rainfall Event containing rain-gauge boundary data, the Rainfall Profile is over-ridden and depends on which rain-gauge boundary contains the mesh elements. See Spatially Varying Rainfall.	rainfall_profile	Text	64		0
Infiltration surface	The name of the Infiltration Surface (2D) applied to this zone.	infiltration_surface_id	Text	64
Turbulence Model	The name of the Turbulence Model (2D) associated with this zone. The specified turbulence model will be used as the default for the 2D zone, i.e. it will be applied to all 2D mesh elements that are not contained in specific Turbulence Zones (2D).	turbulence_model_id	Text	64
Rainfall percentage	Percentage indicating how much of the rainfall depth will fall directly onto the ground within the 2D zone. Used to avoid double counting, e.g. of rainfall falling onto building roofs and flowing directly into the drainage system.	rainfall_percentage	Double			3		0	100
Mesh summary	Read-only field containing meshing summary data (e.g. ground model, data source for voids, break lines and walls, mesh zones used, number of triangles etc.), a list of mesh warnings and resampling information. Only the latest meshing information is stored in this field. Previous meshing summary information will be overwritten if re-meshing of the zone takes place and the mesh results are loaded. See Creating 2D meshes.	mesh_summary	Memo			0
Mesh data	Clicking displays the 2D Mesh Element Histogram dialog.	mesh_data	Array			0
Subgrid Sampling	If checked, Subgrid Sampling is applied to the 2D zone during mesh generation. Note: Subgrid Sampling (Tech preview) is only available using Clip meshing method of Mesh generation. See Subgrid Sampling Methodology for details.	subgrid_sampling	Boolean
Subgrid Sampling triangle area	Enabled when Subgrid Sampling is checked and provides a measure of mesh resolution for Subgrid Sampling when creating a 2D mesh. The maximum area for subgrid triangles in a 2D element. This value must be less than the specified Maximum triangle area. This applies to all subgrid triangle areas in the 2D zone that are not in a mesh zone. This parameter also determines the first entry in the volume/level tables. ICM aggregates the triangle areas of the first triangles in the volume/level tables until the specified maximum area is reached, which becomes the first entry in the volume/level table.	subgrid_triangle_area	Double		NA	3	10	0.001