Topological Error

The concept of Topological Error is a data issue in which a GIS dataset does not conform to certain topological relationships or connectivity requirements of geographic features. Overlapping polygons, gaps between connected features, dangling lines, duplicate geometries, and wrong connections between two features are among common topological errors. Topological errors may impact data analysis, mapping process, data editing operations, and geoprocessing.

GIS uses topological relationships for defining the connections between points, lines, and polygons in a dataset. For instance, neighboring plots of lands must share a common boundary, and no gaps or overlapping areas may occur; and a system of roads must be connected at their intersection. With the help of topological validation of a GIS dataset, topological errors may be found and fixed. Correct topological connections improve spatial data quality and allow performing spatial analysis with higher reliability.