On the Edit tab, in the Manage Edits group, Map Topology enables editing of visible features as topological edges and nodes. Enabling a geodatabase topology rule limits map topological editing to only the layers that participate in the selected geodatabase topology.
For a list of editing tools that edit topological edges and nodes when you enable map topology, see Modify Features tool reference.
Editing features as map topological edges and nodes maintains feature contiguity by enforcing edges to remain coincident as you edit features. Map topology requires no setup. When it is enabled, it appears as a highlighted graph of edges and nodes that correlate directly to the visible features you are editing.
Editing tools that can switch between editing finished features and map topology contain Features and Edges tabs that allow you to toggle between these editing modes. The workflow for editing features using map topology is similar to moving or editing features, except the features that share an edge or a node are also automatically edited and remain contiguous when you finish the edit.
If you attempt to finish edits that break the topology graph, the message Edit operation failed appears, and your changes are canceled.
Map topology options
On the Map Topologies Options dialog box, the cluster tolerance is the distance within which edges and vertices are determined to be coincident. By default, ArcGIS Pro automatically calculates a minimum possible value. You can specify a custom tolerance. For most use cases, the automatic setting is the best practice.
Increasing the cluster tolerance can potentially reduce the spatial accuracy of your data and cause features to collapse or distort. This occurs as more feature elements are snapped together and determined to be coincident.
Geodatabase topology is a rules-based methodology that involves defining spatial relationships in the source geodatabase, validating them in a map, and fixing the errors. Spatial relationships that violate a rule are symbolized as errors on separate topology layers in your map. The status of a topology, including errors and exceptions, is saved to the source geodatabase.
For example, in a geodatabase, you can define a topology for features contained in a Roads dataset and specify that all road and highway intersections must include a coincident point feature. After creating or editing these features, you can validate your work, identify the features that do not conform to this rule, and edit the features to make corrections.
To learn how to create geodatabase topology, see Create a topology.
Validating geodatabase topology
Geodatabase topologies model spatial relationships by representing features as topological primitives. When you validate a topology, an alternative rules-based topological view of your feature geometry is generated as group layers. You can fix errors using predefined fixes or common editing tools.
To learn how to validate a geodatabase topology and fix errors, see Validate and fix geodatabase topology.
Network topology is used exclusively by utility networks to maintain network connectivity and contiguity among visible network features. It uses connectivity rules and associations to model physical networks in built environments. Utility networks do not participate in map topology.
For example, moving a duct bank also moves its contents, or moving a pole also moves a transformer attached to it. You can also run a trace and identify connected features, determine flow characteristics of a commodity such as water or electricity based on feature attributes, and perform other analytic operations.
To learn more, see About network topology.
Validating network topology
When you edit a utility network, the modified area is symbolized on a sublayer named dirty areas. When the network topology is disabled, a single dirty area is created over the entire network. When the network topology is enabled, a dirty area is generated whenever an edit is made to the network.
To learn more, see Validate a network topology.