Once the geometry errors have been identified, the work of repairing the layer begins. In Chapter 1, A Refreshing Look at QGIS, we covered basic vector data editing that included layer-based snapping. In this final section, we will cover how to repair topological geometry errors via topological editing. We will continue to use the parcels.shp data as an example.
The editing approach taken depends on the topological error you are addressing. In the last section, three types of errors were found: gaps, overlaps, and duplicate geometries. These are three of the most common errors associated with polygon data, and we will look at how to repair these three types of errors.