Geometric Network

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Geometric Network

• Robert Borchert
• GIS Technician
• United Services Group
• Great River Energy

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Geometric Network

• What is a Geometric Network?
• Why you may want a Geometric Network?
• Why may you not want a Geometric Network?

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Geometric Network

• Examples of how you can use a Geometric Network.
• What is required to create a Geometric Network?
• Basic procedure to create a Geometric Network.

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Geometric Network

• Some of the problems you may encounter when
  creating or using your Geometric Network.
• Steps you can take before starting.

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What is a Geometric Network?

• Single dimension non-planar graph with features.
• Edge elements and junction elements connected by
  topology.

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Or more simply

• The GIS knows how things are connected from point
  A to point B.
• Direction of flow.
• Source to end
• Dot to Dot puzzle.

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Connecting the Dots

• Collection of numbered Dots
• Connected by lines

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Connecting the Dots

• What are the Dots and Lines?
• Substations
• Reclosers
• Fuses
• Transformers
• Customers
• Underground or Overhead Conductor

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What is a Geometric Network?

• Direction of Flow
• Path of travel
• From substation to customer
• Multiple branches
• Independent of polyline direction

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Why You May Want AGeometric Network?

• Generate Reports
• Find B phase transformers and total kV on north
  feeder
• Select Create Reports or Crystal Report Wizard
• Outage management tool
• Drawing errors
• Unconnected elements
• Loops
• More efficient editing
• Keeps elements connected

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Why You May Not Want AGeometric Network

• Less efficient editing.
• Only one network element per location.
• Cannot load new data.
• Labor intensive.

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Examples of How You Can Use A Geometric Network

• Utility Network Analyst
• Tracing
• Downstream
• Upstream
• Outage Management Tool
• Find Loops
• Mass Selection and Update

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Utility Network Analyst Toolbar
Flags and Barriers
Trace Task
Solve Button
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Tracing

• Downstream Trace
• Add Flag
• Perform Trace (SOLVE button)
• Upstream Trace
• Place the Flag
• Perform Trace (SOLVE button)
• Traces a direct path

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Outage Management Tool

• Customer calls
• Place Flag
• Perform Trace Upstream
• Highlights possible problem spots
• Transformer
• Fuse
• Recloser

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Outage Management Tool

• Second Customer calls
• Place second flag on that customer
• Find Common Ancestors
• Highlights common components
• Third Customer calls
• Fourth Customer calls

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Find Loops

• Drawing error
• Circuit crosses back to itself
• i.e. short circuit
• Missing element
• Switch
• Open
• Etc
• Crossing lines

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Find Loops

• Place flag at substation or on the conductor
• Find loops
• Perform Trace
• Make corrections
• Proper flow established

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Mass Selection and Update

• Set selectable Layers
• Customers
• Place flag
• Perform trace Downstream
• Update based on Selection
• Attributes Window
• Calculate Values

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What is Required to Create A Geometric Network?

• ArcEditor or ArcInfo
• ArcCatalog
• Geodatabase
• Same Feature Dataset
• Standard Data Model
• Note on ArcView
• Cannot edit network elements

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Basic Procedure to Create AGeometric Network

• Make a backup
• Can corrupt your drawing

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Basic Procedure to Create A Geometric Network

• Start ArcCatalog
• Right Click the Feature Dataset
• Select
• New
• Geometric Network

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Build Geometric Network Wizard

• Step by step wizard

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Build Geometric Network Wizard

• Build a geometric network from existing features

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Build Geometric Network Wizard

• Select the features classes and name for your
  Geometric Network

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Build Geometric Network Wizard

• Enabled values

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Build Geometric Network Wizard

• Complex or Simple edges

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Build Geometric Network Wizard

• Snapping

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Build Geometric Network Wizard

• Sources and Sinks

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Build Geometric Network Wizard

• Weights

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Build Geometric Network Wizard

• Summary

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Build Geometric Network Wizard

• Building the Geometric Network

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Build Geometric Network Wizard

• Same Feature Set as Network Elements

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Problems

• Only one Feature Class per location
• That is the same X,Y value
• By design
• Loops
• Missing drawing items
• Incorrectly placed polylines
• Many features may not be connected
• Automatic snapping in the Build Geometric Network
  Wizard

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Automatic snapping in the Build Geometric Network
Wizard
Before Snapping
After Snapping

• CAUTION

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Problems

• Cannot produce flow from the substation or source
• Check the AncillaryRole and Enabled fields
• AncillaryRole substations are the source
• 0 - None
• 1 - Source
• 2 - Sink
• Enabled a component is active or inactive in
  the network
• 0 - False
• 1 - True

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Steps You Can TakeBefore Starting

• Point features are connected
• Select By Location
• Do not use Buffer
• Mark those points
• Connect Points

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Steps You CanTake Before Starting

• Determine position of switches and status of
  areas where there can be an open
• Update a column with that status
• 0 False Open
• 1 True Closed
• Can then update the Enabled field after creating
  your network
• If you delete your Geometric Network the Enabled
  field remains intact

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Setting Flow Direction

• Start an edit session
• Generate Flow Button

Generate Flow
Flags and Barriers
Solve Button
Trace Task
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Set Flow Direction

• Set Flow Button

• Display Arrows Button

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Questions?