Polygon Objects

A polygon is made up of a series of vertices and edges. Vertices can be moved, deleted or added. Vertices can also be snapped to vertices of other polygon or polyline objects. These shared vertices can then be moved together. See the Advanced Polygon and Polyline Editing section for details on editing polyline geometry.

The following polygon objects are available in both InfoWorks and SWMM networks:

• General Polygons - provide a method for specifying a geographical area on the GeoPlan Window:
  • as a bounding polygon when generating subcatchment boundaries using Thiessen polygons
  • to define areas of a Ground Model in which height correction is required
  • to represent voids when generating a 2D mesh
• TVD Connectors - used to create a link between data streams in a time series database and the network. These may have point or polygon geometry.
• Spatial Rain Zones - used to define areas within the network to which rainfall will be applied (applicable to Spatial Time Series Database objects only)
• Spatial Rain Sources -used to specify rain sources to be applied to spatial rain zones during simulation, as well as their priority (valid for Spatial Time Series Database objects only)
• 2D Zones - used as the bounding polygon for a 2D mesh
• Roughness Zones - used to divide a 2D zone into regions of different roughness
• Roughness Definitions - not a polygon object, but associated with a 2D Zone or Roughness Zone to allow roughness to be defined as a function of depth
• Mesh Zones - used to divide a 2D Zone into regions of different mesh resolution
• Mesh Level Zones - used to define areas in which mesh element elevations are to be modified based on ground model elevations or user-defined values
• Porous Polygons - used to represent enclosed walls of specified porosity and height

The following polygon objects are only available in InfoWorks networks:

• Storage Areas - used to define the plan area at ground level of a storage or pond node
• 2D IC Zones (hydraulic, water quality, infiltration and sediment) - used to define areas in which initial condition values apply within a 2D mesh
• Infiltration Zones (2D) - used to define areas within the 2D Zone to which infiltration will be applied
• Infiltration Surfaces (2D) - not a polygon object, but associated with an Infiltration Zone to provide infiltration characteristics
• Turbulence Zone (2D) - used to represent the physical area in which eddy viscosity is to apply
• Turbulence Model (2D) - not a polygon object, but associated with a 2D Zone or Turbulence Zones (2D) to provide turbulence characteristics
• Permeable Zone (2D) - used to provide a link between infiltrated volume from the 2D surface into the 1D system
• Network Results Polygons (2D) - used to interrogate results within a 2D mesh
• Risk Impact Zones - used to aggregate the results from individual Damage Receptors into geographical groupings
• Building - used to represent rain falling onto a roof of a building and entering the drainage system and/or remaining on the surface, and to define an area where roughness, mesh levels and porosity are applied within a 2D mesh.
• ARMA model - not a polygon object but may be associated with a TVD connector and a subcatchment. It defines the type of error calculation to be performed and the autoregressive (AR) and the moving average (MA) coefficients to be used in the ARMA predictions.