ggmapcn (version 0.3.0)

basemap_vege: Vegetation Map of China Layer for ggplot2

Description

Adds a vegetation raster map of China to a ggplot2 plot, with color-coded vegetation types.

Usage

basemap_vege(
  color_table = NULL,
  crs = NULL,
  maxcell = 1e+06,
  use_coltab = TRUE,
  na.rm = FALSE,
  ...
)

Value

A ggplot2 layer object representing the vegetation map of China.

Arguments

color_table

A data frame containing vegetation types and their corresponding colors. It should have columns "code" (raster values), "type" (vegetation names), and "col" (hex color codes). If NULL, a default color table based on standard vegetation classifications for China is used.

crs

A character string specifying the coordinate reference system for the projection. If NULL, the default projection "+proj=aeqd +lat_0=35 +lon_0=105 +ellps=WGS84 +units=m +no_defs" is applied.

maxcell

An integer indicating the maximum number of cells for rendering to improve performance. Defaults to 1e6.

use_coltab

A logical value indicating whether to use the color table for raster values. Default is TRUE.

na.rm

A logical value indicating whether to remove missing values. Default is FALSE.

...

Additional parameters passed to `geom_spatraster`.

References

Zhang X, Sun S, Yong S, et al. (2007). *Vegetation map of the People's Republic of China (1:1000000)*. Geology Publishing House, Beijing.

Examples

# \donttest{
# Example1: Check and load the vegetation raster map

# Make sure the required raster data is available
check_geodata(files = c("vege_1km_projected.tif"))

# Once the data is checked or downloaded, add the vegetation raster to a ggplot
ggplot() +
  basemap_vege() +
  theme_minimal()

# Example2: Customize color table
custom_colors <- data.frame(
  code = 0:11,
  type = c(
    "Non-vegetated", "Needleleaf forest", "Needleleaf and broadleaf mixed forest",
    "Broadleaf forest", "Scrub", "Desert", "Steppe", "Grassland",
    "Meadow", "Swamp", "Alpine vegetation", "Cultivated vegetation"
  ),
  col = c(
    "#8D99B3", "#97B555", "#34BF36", "#9ACE30", "#2EC6C9", "#E5CE0E",
    "#5BB1ED", "#6494EF", "#7AB9CB", "#D97A80", "#B87701", "#FEB780"
  )
)
ggplot() +
  basemap_vege(color_table = custom_colors) +
  labs(fill = "Vegetation type group") +
  theme_minimal()
# }