Polygon Sliver

Available with ArcGIS Pro Standard and Data Reviewer licenses.

Summary

Sliver polygons are usually small polygons resulting from overlay operations, such as Intersect or Union. Sliver polygons typically have an area that is much smaller than the perimeter. The Polygon Sliver check finds polygon features with a thinness ratio below a specified threshold. Optionally, you can require that the area of each polygon is below a maximum area threshold.

Supported workflows

ArcGIS Data Reviewer checks support multiple methods for implementing automated review of data. The following table identifies the supported implementation methods for this check:

Workflow	Supported	Licensing
Validation attribute rule	Yes (ArcGIS Pro 2.9 and ArcGIS Enterprise 10.9.1 or later)	Available with ArcGIS Pro Standard and Data Reviewer license
Constraint attribute rule	No	N/A
Run Data Checks	Yes (ArcGIS Pro 3.5 or later)	Available with Data Reviewer license

Overview

Polygon slivers can occur during data extraction when small, thin polygons are created due to an overlap with existing features. Tiny sliver polygons or gaps between polygons often result from creating polygons without using snapping or from editing shared boundaries without a topology. A sliver polygon is defined by its thinness ratio and maximum area. If a polygon is below a specified thinness ratio and area, it is considered a sliver. You can run this check on an entire feature class, a subtype, or a set of features selected using an SQL query.

Attribute Rule syntax

The following table describes the validation attribute rule parameters:

Parameter	Required	Description	Workflow
Subtype	No	The subtype(s) to which the rule is applied.	Validation
Attribute	No	A query that identifies the features to which the rule is applied.	Validation
Thinness Ratio	Yes	The thinness ratio (T) between a feature’s area (A) and its perimeter (P) is calculated using the following equation: T = 4π(A/P²) A thinness ratio of 1 is a perfect circle and a thinness ratio of 0 is a line. This measure takes a maximum value of 1 for a circle. Objects of regular shape have a higher thinness ratio than irregular ones.	Validation
Maximum Area	No	The maximum area that is considered a sliver. If the polygon's area is equal to or less than this value, it is considered a sliver. The default unit of measure is the input data source's horizontal spatial reference.	Validation
Name	Yes	A unique name for the rule. This information is used to support data quality requirement traceability, automated reporting, and corrective workflows.	Validation
Description	No	A description of the error you define when a noncompliant feature is found. This information is used to provide guidance for corrective workflows.	Validation
Severity	No	The severity of the error assigned when a noncompliant feature is found. This value indicates the importance of the error relative to other errors. Values range from 1 to 5, with 1 being the highest priority and 5 being the lowest.	Validation
Tags	No	The tag property of the rule. This information is used in rule authoring and management workflows to support traceability and reporting of data quality requirements.	Validation

Run Data Checks syntax

The following table describes the Run Data Checks parameters:

Parameter	Required	Description
Input Feature	Yes	The input feature layer that is evaluated by the rule. Note: You can disable a map selection or layer definition query using the toggle button that honors the selection or filter before evaluation. Layer definition queries that include a spatial clause are not supported.
Attribute Filter	No	A query that identifies the features to which the rule is applied.
Thinness Ratio	Yes	The thinness ratio (T) between a feature’s area (A) and its perimeter (P) is calculated using the following equation: T = 4π(A/P²) A thinness ratio of 1 is a perfect circle and a thinness ratio of 0 is a line. This measure takes a maximum value of 1 for a circle. Objects of regular shape have a higher thinness ratio than irregular ones.
Maximum Area	No	The maximum area that is considered a sliver. If the polygon's area is equal to or less than this value, it is considered a sliver. The default unit of measure is the input data source's horizontal spatial reference.
Name	Yes	A unique name for the rule. This information is used to support data quality requirement traceability.
Extent	Yes	Visible Extent—Evaluate the visible extent of the map. Full Extent—Evaluate the full extent of the data.

Notes

• The Attribute parameter is limited to comparison (=, <>, >, <, >=, <=) and logical (AND/OR, IN/NOT IN, LIKE/NOT LIKE, IS NULL) operators.

• The Attribute filter parameter does not support the following field types: Big Integer, Date Only, Time Only, and Timestamp Offset. If selected, the row header is marked in red and does not allow the rule to be saved.