- 26 Aug 2022
- 2 Minutes to read
The Urban Junction Node
- Updated on 26 Aug 2022
- 2 Minutes to read
Junction nodes represent manholes and drains in your urban system, and connections between pipes.
External Urban Inflow can enter the system at Junctions. Excess water at a Junction node can either be lost from the system, or be allowed to pond and subsequently drain back into the junction.
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Rules of Junction nodes
A Junction node may have multiple inflow Conduit Links connected. Multiple outflow links from a Junction node are also allowed if using Dynamic Wave routing. If using Steady-State or Kinematic Wave routing, only a single outflow link is possible from a Junction node; an Urban Divider Node may be suitable if two outflow links are required.
The Junction node name by default will be provided by parameters setup in the Urban Model Defaults menu.
The x and y coordinates of the Junction node are shown in these fields. These values are automatically populated based on the node location on the map.
This field allows for an optional text description. The field will be blank by default.
This field allows for an optional text tag, to allow you to categorise units. The field will be blank by default.
Inflows can be specified for a Junction node. These can be external direct, dry weather or RDII inflows. If inflows are not defined, the Junction node will only receive inflow from any Urban Subcatchment Nodes with the Junction node label selected as the subcatchment outlet.
Addition of pollutants is not currently available within the software. If your model already contains defined pollutants, these will be unaffected, however you will not be able to access the pollutant editor form.
General node parameters
The invert elevation of the Junction is provided in this field. By default this value will be provided by parameter setup in the Urban Model Defaults menu.
The maximum depth of the Junction, from ground surface to invert, is provided in this field. If zero, then the distance from the invert to the top of the highest connecting link will be used. By default this value will be provided by parameter setup in the Urban Model Defaults menu.
This field contains the initial water depth in the Junction at the start of the simulation. By default this value will be 0.
This field specified the additional depth of water beyond the maximum depth that is allowed before the Junction floods. This parameter can be used to simulate bolted manhole covers. By default this value will be 0.
A positive ponded area for the Junction node can be provided in this field. This allows water that leaves the Junction node to pond, and subsequently re-enter the Junction node if conditions allow. By default this value will be provided by parameter setup in the Urban Model Defaults menu.
Note that to utilise this parameter, it is also necessary to allow ponding in the Urban Model Settings menu.
The Ponded Area parameter is used differently if working with integrated modelling.