Visualise categorical field data

15 minutes

Today’s exercises are designed to refresh your memory of how to adjust the symbology of vector data in QGIS. In other words, you’ll practice displaying your field data in different ways

We’ll start with visualising categorical data, also known as qualitative, thematic or nominal data

If you’re working with you own field data, select a column that contains categories, either as text (site names, species, named vegetation types) or numbers (e.g. numerical code for vegetation type or observer)

If you’re working with the water beetle example data, the categorical variables are the taxonomic information: Scientific name, Common name and Family

1. Open the layer properties - double-click or right-click > Properties)
2. Select the Symbology tab from the left-hand menu
3. Select Categorized from the dropdown menu at the top
4. Choose the column you want to symbolise from the Value dropdown menu; for the water beetle dataset, we’ll choose Family
5. Click on the Classify button in the bottom left
6. Click Apply and OK to finish

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• Open the layer properties - double-click or right-click > Properties)

• Select the Symbology tab from the left-hand menu

• Select Categorized from the dropdown menu at the top

• Choose the column you want to symbolise from the Value dropdown menu; for the water beetle dataset, we’ll choose Family

• Click on the Classify button in the bottom left

• Click Apply and OK to finish

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