Plot Multiple Vector Layers

Last updated on 2025-12-09 | Edit this page

Overview

Questions

  • How can I create map compositions with custom legends using ggplot?
  • How can I plot raster and vector data together?

Objectives

  • Plot multiple vector layers in the same plot.
  • Apply custom symbols to spatial objects in a plot.
  • Create a multi-layered plot with raster and vector data.
Prerequisite

Things You’ll Need To Complete This Episode

See the lesson homepage for detailed information about the software, data, and other prerequisites you will need to work through the examples in this episode.

This episode builds upon the previous episode to work with vector layers in R and explore how to plot multiple vector layers. It also covers how to plot raster and vector data together on the same plot.

Load the Data

To work with vector data in R, we can use the sf library. The terra package also allows us to explore metadata using similar commands for both raster and vector files. Make sure that you have these packages loaded.

We will continue to work with the three ESRI shapefile that we loaded in the Open and Plot Vector Layers in R episode.

Challenge

Challenge: Plot Raster & Vector Data Together

You can plot vector data layered on top of raster data using the + to add a layer in ggplot. Create a plot that uses the NEON AOI Canopy Height Model data/NEON-DS-Airborne-Remote-Sensing/HARV/CHM/HARV_chmCrop.tif as a base layer. On top of the CHM, please add:

  • The study site AOI.
  • Roads.
  • The tower location.

Be sure to give your plot a meaningful title.

R 

ggplot() +
  geom_raster(data = chm_harv_df, aes(x = x, y = y, fill = HARV_chmCrop)) +
  geom_sf(data = lines_harv, color = "black") +
  geom_sf(data = aoi_boundary_harv, color = "grey20", size = 1) +
  geom_sf(data = point_harv, pch = 8) +
  ggtitle("NEON Harvard Forest Field Site w/ Canopy Height Model") +
  coord_sf()
Key Points
  • Use the + operator to add multiple layers to a ggplot.
  • Multi-layered plots can combine raster and vector datasets.
  • Use the show.legend argument to set legend symbol types.
  • Use the scale_fill_manual() function to set legend colors.