Get started with bcmaps

In bcmaps: Map Layers and Spatial Utilities for British Columbia

Overview

bcmaps is an R package of spatial map layers for British Columbia.

bcmaps provides access to various spatial layers of British Columbia, such as administrative boundaries, natural resource management boundaries, watercourses, census boundaries, etc. All layers are available as sf objects in the BC Albers projection, which is the B.C. Government standard.

Most layers are accessed directly from the B.C. Data Catalogue using the bcdata R package under the hood. See each layer's individual help file for more detail.

IMPORTANT NOTE Support for Spatial objects (sp) was removed in {bcmaps} v1.3.0. Please use sf objects with {bcmaps}. A discussion on the evolution of the spatial software stack in R can be found here: https://r-spatial.org/r/2022/04/12/evolution.html.

Usage

To see the layers that are available, run the available_layers() function:

library(bcmaps)
available_layers()

Most layers are accessible by a shortcut function by the same name as the object. Then you can use the data as you would any sf object. The first time you try to access a layer, you will be prompted for permission to download that layer to your hard drive. Subsequently that layer is available locally for easy future access. For example:

library(sf)

bc <- bc_bound()
plot(st_geometry(bc))

There are two British Columbia boundary map layers available in bcmaps:

• bc_bound() for fast plotting with suitable detail for most figures (source: (7.5M) Provinces and States - The Atlas of Canada Base Maps for BC)
• bc_bound_hres() for geospatial analyses requiring detailed lineworks of British Columbia (source: Province of British Columbia - Boundary Terrestrial)

Simple Features objects

By default, all layers are returned as sf spatial objects:

library(bcmaps)
library(sf)

# Load and plot the boundaries of B.C.

bc <- bc_bound()
plot(st_geometry(bc))

## Next load the Regional Districts data, then extract and plot the Kootenays
rd <- regional_districts()
kootenays <- rd[rd$ADMIN_AREA_NAME == "Regional District of Central Kootenay", ]
plot(st_geometry(kootenays), col = "lightseagreen", add = TRUE)

Digital Elevation Model for British Columbia 1:250,000

The cded_raster and cded_stars functions return the 1:250,000 digital elevation model for British Columbia bounded by some area of interest. Here we are retrieving the area bounded by the Logan Lake census subdivision:

library(raster)

aoi <- census_subdivision()[census_subdivision()$CENSUS_SUBDIVISION_NAME == "Logan Lake", ]
aoi_raster <- cded_raster(aoi)
plot(aoi_raster)

It's a beautiful day in the neighbourhood

A handy layer for creating maps for display is the bc_neighbours layer, accessible with the function by the same name. This example also illustrates using the popular ggplot2 package to plot maps in R using geom_sf and the bc_cities() function available in bcmaps:

library(ggplot2)
ggplot() +
  geom_sf(data = bc_neighbours(), mapping = aes(fill = name)) +
  geom_sf(data = bc_cities()) +
  coord_sf(datum = NA) +
  scale_fill_viridis_d(name = "Jurisdiction") +
  theme_minimal()

Biogeoclimatic Zones

As of version 0.15.0 the B.C. BEC (Biogeoclimatic Ecosystem Classification) map is available via the bec() function, and an accompanying function bec_colours() function to colour it:

bec <- bec()
library(ggplot2)
bec_sub <- bec[bec$ZONE %in% c("BG", "PP"),]
ggplot() +
  geom_sf(data = bec_sub,
          aes(fill = ZONE, col = ZONE)) +
  scale_fill_manual(values = bec_colors()) +
  scale_colour_manual(values = bec_colours())

Updating layers

When you first call a layer function bcmaps will remind you when that layer was last updated in your cache with a message. For a number of reasons, it might be necessary to get a fresh layer in your bcmaps cache. The easiest way to update is to use the force argument:

ep <- ecoprovinces(force = TRUE)

Another option is to actively manage your cache by deleting the old layer and calling the function again:

show_cached_files()
delete_cache('ecoprovinces')
ep <- ecoprovinces()

Utility Functions

The package also contains a few handy utility functions:

• transform_bc_albers() for transforming any sf object to BC Albers projection
• bc_area() to get the total area of British Columbia in various units
• bc_bbox() to get an extend/bounding box for British Columbia

bcmaps documentation built on July 4, 2024, 1:09 a.m.