Hands-On Geospatial Analysis with R and QGIS

Supervised classification in QGIS

We will classify landsat 8 images looking at different land use patterns. We will use Band 3 (red), Band 4 (near infrared), and Band 5, or shortwave infrared (SWIR), here. We use the band combination 5, 4, and 3 for a color infrared (CIR) image. In the following outputs, vegetation will pop up as red, and dead or unhealthy plants will appear in less intense red, green, pink, or tan. Sandy soil will appear as white, gray, or light tan, and water and roads will appear as shades of blue to black.

First, we load bands 3, 4, and 5 from folder 2 under the Mosaic folder, which is inside the Data folder of Chapter 4:

As landsat is multispectral and as we want to work with three bands, we need to make a false color ...