Typically, raw data that's obtained for a Geographic Information System (GIS) project needs to be massaged for use in a specific application. It may need to be merged, converted into a different geometry type, saved to the coordinate reference system of the project, subset to the extent of the study area, or subset by attribute values. While QGIS provides a powerful set of tools that can handle many types of vector preparation and transformation tasks, this chapter will cover what we consider to be commonly used vector preparation tasks. Many of the tools that will be covered in this chapter can be found in the Vector menu in QGIS; however, others are available in the processing toolbox.
The following topics will be covered in this chapter:
- Merging vectors
- Converting vector geometries
- Adding geometry columns to an attribute table
- Using basic vector Geoprocessing tools
- Defining coordinate reference systems
- Advanced field calculations