Topologia

ArcGIS Geodatabase Topology Rules
®
Topology in ESRI® ArcGIS® allows you to model spatial relationships between feature classes in a feature dataset. Topology rules allow you to define those relationships between features in a single feature class or subtype or between two feature classes or subtypes. Topology rules allow you to define the spatial relationships that meet the needs of your datamodel. Topology errors are violations of the rules that you can easily find and manage using the editing tools found in ArcMap™.

How to read these diagrams:
The topology rule occurs within a single feature class or subtype.

Topology rule name
Description and example of a valid case of the specified topology rule. Description and example of a case of the specified topology rule where errorsexist and will be returned. For each example, the error shape is shown in bright red. Description of a real-world application of the specified topology rule.

:
The topology rule occurs between two different feature classes or subtypes.

Generalized description of when to use this rule.

Must not overlap

Must not have gaps

Line or Polygon

Must be larger than cluster toleranceMust not have pseudonodes

Polygon

Polygon Line

Polygons must not overlap within a feature class or subtype. Polygons can be disconnected or touch at a point or touch along an edge.

Line

Polygons must not have a void between them within a feature class or subtype.

Polygon errors are created from areas where polygons overlap. A voting district map cannot have any overlaps in itscoverage.

Line errors are created from the outlines of void areas in a single polygon or between polygons. Polygon boundaries that are not coincident with other polygon boundaries are errors. Soil polygons cannot include gaps or form voids—they must form a continuous fabric.

Cluster tolerance is the minimum distance between vertices of features. Vertices that fall within the cluster toleranceare defined as coincident and are snapped together.

Cluster Tolerance

Cluster Tolerance

Any polygon or line feature that would collapse when validating the topology is an error.

The end of a line cannot touch the end of only one other line within a feature class or subtype. The end of a line can touch any part of itself.

Point errors are created where the end of a line touches theend of only one other line. For hydrologic analysis, segments of a river system might be constrained to only have nodes at endpoints or junctions.

Use this rule to make sure that no polygon overlaps another polygon in the same feature class or subtype.

Use this rule when all of your polygons should form a continuous surface with no voids or gaps.

This rule is applied to all line and polygonfeature classes that participate in the topology.

Soil polygons must be larger than the cluster tolerance.

Use this rule to clean up data with inappropriately subdivided lines.

Contains point

Contains one point

Must not have dangles
Polygon errors are created from the polygons that do not contain exactly one point. Point errors exist where points are not within a single polygon.Parcels must contain exactly one address point.

Must not self overlap

Polygon

Line

n n n

n n n n n n n n

n n

Point errors are created at the end of a line that does not touch at least one other line or itself.

Line

Each polygon of the first feature class or subtype must contain within its boundaries at least one point of the second feature class or subtype.

PolygonPolygon errors are created from the polygons that do not contain at least one point. A point on the boundary of a polygon is not contained in that polygon.

n

Each polygon must contain exactly one point. Each point must fall within a polygon.

The end of a line must touch any part of one other line or any part of itself within a feature class or subtype.

25

Lines must not overlap...