Overview
This lecture explains how to identify, resolve, and prevent common topology errors within a utility network using ArcGIS Pro, focusing on connectivity, stacked points, and midspan errors.
Utility Network Topology Basics
- Utility networks use a graph structure to model connections between spatial features.
- A valid network topology ensures accurate tracing and analysis.
- Topology errors commonly occur when migrating data from systems without strict topology enforcement.
Types of Topology Errors and Solutions
Edge-Edge Errors (Error 10)
- Occur when two line (edge) features of different types connect directly, violating network rules.
- Must insert a junction or device (e.g., tap fitting) at the intersection to resolve.
- Validate the network topology after correction to clear errors.
Stacked Point Errors (Error 25)
- Happen when two devices or junctions are placed at the same location.
- Move one feature away from the stack or delete one to resolve.
- Offsetting devices and using connectivity associations can prevent new stacked errors.
Midspan Connectivity Errors (Error 13)
- Caused when features connect midspan on lines that only allow endpoint connections.
- Split the line at the connection point to resolve.
- Adjust network rules only if many such errors are found and justified.
Midspan Terminal Device Errors (Error 38)
- Devices with multiple terminals cannot be placed midspan on a line.
- Split the line and assign each segment to the correct terminal on the device.
- Correct terminal assignments ensure proper flow and isolation in network tracing.
Preventing Topology Errors
- Follow drawing standards for feature placement in utility networks.
- Use connectivity associations for multiple devices at a location instead of stacking.
- Validate all changes and save edits regularly to maintain network integrity.
Key Terms & Definitions
- Utility Network — A system in ArcGIS for modeling and analyzing utility infrastructure.
- Topology — The arrangement and connection rules between features in a spatial network.
- Dirty Area — Map indication of edits needing topology validation.
- Edge — A linear feature (e.g., pipe, cable) in a network.
- Junction/Device — Point feature enabling connections between edges.
- Connectivity Association — A logical link between features not physically connected.
- Terminal — Connection point on a device, used for tracking network flow.
Action Items / Next Steps
- Complete topology error corrections in ArcGIS Pro as shown.
- Validate and save your edits after every correction.
- Review the tutorials on managing connectivity errors and utility data for deeper understanding.
- Explore "Configure rules for a utility network" to learn about rule-based prevention of topology errors.