3. Basic GIS Operations#

The third module addresses operations and data manipulation that GIS practitioners will undertake frequently. The first chapter teaches the process of digitisation, which is the process of creating geodata, either from existing images, or maps, or from your own knowledge. After data collection, digitisation lets you prepare the collected data for spatial analysis in QGIS. It is also useful to communicate the spatial distribution of phenomena or to simply show the collected data on a map. Next, the second chapter focuses on the classification of geodata. Spatial data can have a lot of information stored in the attribute table and the classification of geodata puts this information into distinct classes. Through this classification, we can gain new insights and it lets us visualise geographic data on maps. The third chapter, covers selecting and querying geodata. For example, you can select all data entries that are under a certain distance from a point, or you could simply select data based on specific values and see their spatial distribution.

Chapter

Competences & Objectives

Chapter 1: Digitisation

At the end of this chapter, you should:

  • understand the process of digitisation,

  • know how to create and edit vector data,

  • know which digitising errors to avoid.

Chapter 2: Geodata Classification

At the end of this chapter, you should:

  • know how to classify geodata in order to gain useful insights,

  • know how and when to use categorised classification,

  • know how and when to use graduated classification.

Chapter 3: Geodata Selection and Queries

At the end of this chapter, you should:

  • know how to select features manually,

  • know how to select features based on attributes,

  • know how to formulate a data query with the expression builder,

  • know how to select features by location,

  • know the geometric operators.

Chapter 4: Georeferencing

At the end of this chapter, you should:

  • know how to georeference a map in QGIS,

  • know how to set the transparency of a georeferenced (raster) layer.

  • know how to digitise vector features from a georeferenced map.

Exercises for Module 3

Here you can find all the exercises for module 3.