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QGIS SWMM Junctions Set Attributes: Difference between revisions

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== Introduction ==
This tool sets SWMM junction attributes 'Ymax' (maximum depth), 'Ysur' (maximum surcharge depth), and 'Apond' (area of ponding). The junction attributes are set based on generic rules, and individual nodes may need to be modified.<br>
This tool supports in-place editing if selected in the QGIS processing window.
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<li>'''Input layer:''' The existing junctions layer that willto be updated.
<li>'''Selected features only:''' If nodesnode(s) in the junctions layer have been selected using the 'Select Features' tool, this option will become available. If this is checked on, the tool will only update the nodesselected that have been selectednode(s).
<li>'''Input Subcatchments [optional]:''' The subcatchments layer(s) that the node(s) receive flow from.
<li>'''Input Inlet Usage Layers [optional]:''' The input inlet usage layer(s) that the node(s) are connected to.
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'''Note:''' If 'Edit Feature In-Place' is selected, the tool does not require the 'Input layer' or the 'JunctionAtts' parameters as the tool will override the existing junctions file with the updated attributes.
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[[File:Junctions_Set_Attributes_Dialog_bJunctions_Set_Attributes_Dialog_d.png]]
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=== Recommended Settings ===
 
The recommended settings for junctions within the 2D domain dependsdepend on whether the node receives flow from a subcatchment and whether and how the node is connected to the 2D domain. Below is a description of the input parameters and their recommended values.
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<li>'''General Options:'''
:*'''; Maximum Depth Option (Ymax):'''
::* Set to 0.0:&nbsp; Initializes the Ymax for all junction nodes to 0.0. This option may be overwritten forby nodesthe parameters set in the 'Nodes connected to 2D with inlets (underground pipe network)' section.
::* Leave as is:&nbsp; Leaves the Ymax value as is for all junction nodes. This option only applies forif using 'Edit Feature In-Place' only.
:*'''; Nodes receiving subcatchment flows option (if connected to 2D):'''
::* Based on options selected below:&nbsp; OptionsParameters set belowin arethe following sections will be applied.
::* Set Apond = 0.0; Ysur = 0.0 (overwrites options below):&nbsp; Forces subcatchment outlets to yseuse 0.0 for Ysur and Apond (turns off ponding). When ponding is off, node surcharging is reported as 'flooding' to SWMM and is immediately transferred to the 2D domain.
 
<li>'''Nodes connected to the 2D without inlets (through embankment culvert):'''
: '''Ysur:'''&nbsp; Sets the surcharge at nodes connected to the 2D with inlets. Recommended value is 0.0.
:*'''Ysur:''' 0.0
:* '''Apond:'''&nbsp; ApproximateSet to the approximate area of connectedthe 2D cells associated with the 1D/2D BC culvert connections layer(s). A larger area may improve stability, but may artificially attenuate discharges.
 
<li>'''Nodes connected to 2D with inlets (underground pipe network):'''
:*'''; Maximum depth (Ymax) option (overwrites general setting):'''
::* Set to inlet elevation - node elevation:&nbsp; Sets the Ymax value to the inlet elevation minus the node elevation.
::* Use global option:&nbsp; Sets the Ymax value based on the settingsparameters selectedset in the 'Global optionsOptions' section.
:* '''Ysur:'''&nbsp; Set to 0.0 if using ponding. Otherwise, set to higher than expected depths to prevent flooding.
:* '''Area of ponding:'''&nbsp; Set to the manholeapproximate area of the 2D cells associated with the Inlet Usage connections layer(s).
 
<li>'''Nodes without a 2D connection (underground pipe network):''' When a node is not connected to the 2D, flood losses will be lost from the model resulting in mass losses and inaccurate results. To prevent this, allow ponding (option 1) or make the surcharge depth high (option 2). ▼
<li>'''Nodes without a 2D connection (underground pipe network):'''<br>
:*Option 1:▼
▲<li>'''Nodes without a 2D connection (underground pipe network):''' When a node is not connected to the 2D, flood losses will be lost from the model resulting in mass losses and inaccurate results. To prevent this, allow ponding (option 1) or make the surcharge depth high (option 2).
::*'''Surcharge depth:''' Set to 0.0.▼
▲:*; Option 1:
::*'''Area of ponding:''' Set to some positive value.▼
▲::*''' Surcharge depth:'''&nbsp; Set to 0.0.
:*Option 2:▼
::*'''Surcharge depthArea of ponding:'''&nbsp; Set to asome positive value higher than expected node depths.
▲:*; Option 2:
::*'''Area of ponding:''' Set to 0.0.
::* Surcharge depth:&nbsp; Set to a value higher than any expected depth in the model.
▲::*''' Area of ponding:'''&nbsp; Set to some positive value0.0.
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== Example ==
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{{Video|name=Animation_Junctions_Set_Attributes_01bAnimation_Junctions_Set_Attributes_01c.mp4|width=12351236}}
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Using the 'Edit FeaturesFeature In-Place' tool:
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{{Video|name=Animation_Junctions_Set_Attributes_02bAnimation_Junctions_Set_Attributes_02c.mp4|width=12351236}}
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