Vector data model

The vector data model is best for modeling discrete objects which have clearly defined boundaries and can be counted

Examples of vector features:

• Coral reefs
• Point sources of pollution
• Individual trees or patches of wetland
• Animal movement tracks from GPS collars
• Areas affected by fire or clear-felling

Vector data come in three spatial forms: point, line and polygon. Each vector feature can have multiple attributes

Points

One-dimensional feature with a single x and y coordinate (vertex) This example contains 3 points

Lines

Linear two dimensional feature composed of a series of x and y coordinates (vertices)

This example contains a single line made from 4 vertices

Polygons

Two dimensional feature composed of sequence of x and y coordinates (vertices) where the first and last vertex are identical, creating a closed area

This example contains a single polygon made from 9 vertices

Vector attributes

Information about a feature or record, stored in columns in the attributes table

Quiz: Vector data model

Test your new knowledge with our mini quiz!

Adjust vector symbology

Let’s work with a vector layer in QGIS, and adjust the way the gibbon distribution polygons are displayed

1. Double-click on NomascusConcolor_Distribution in the Layers panel to open the Layer Properties pop-up window
2. Select Symbology from the left-hand menu
3. At the top, under where it says ‘Fill’, click on Simple Fill
4. Click on the Symbol layer type dropdown just below and select Outline: Simple Line
5. Click Apply to see the effect - your polygons should now be drawn as an outline only, with no fill colour
6. Adjust the Color, Stroke width and Stroke style to see the effect of these settings

---