Detect Overlap/Gap

Use it as a first-pass quality check on a parcel layer before building a topology.

• The tool has no dialog. It acts on the layer selected in the Contents pane.
• Two kinds of fault are found in one pass, and each gets its own error layer:

• A flag field — KGA Overlap Flag — is written onto the input layer, marking each feature as an Overlap Feature or a Regular Feature, so the layer itself can be symbolised or queried by fault status.
• Gaps are the fault that is easy to miss visually. An overlap often shows as a darker patch where two symbols stack; a gap is a thin sliver of background that reads as a boundary line. This tool finds them geometrically rather than by eye.
• This tool works within one layer. For faults between two layers, use Detect Overlap Across Layer.

• Unlike Topology Check, no geodatabase topology is created, so this works on shapefiles and on data outside a feature dataset — but there is no error inspector and no way to mark a fault as an accepted exception.

1. In the Contents pane, select the polygon layer to check.
2. On the KGA Toolbox tab, in the Data Management group, open the Feature menu and click Detect Overlap/Gap.
3. Wait for the run to finish. The Overlap Errors and Gap Errors layers are added to the map.
4. Work through the Overlap Errors layer first — an overlap means two records claim the same ground.
5. Then work through Gap Errors. Decide for each whether it is a genuine unrecorded area or a digitising error to be closed.
6. Use the KGA Overlap Flag field on the input layer to symbolise or query the flagged features.

Requires an active KGA Toolbox license. The tool validates the license before running.