2125

Vignemale – CC-BY-NC-SA by Jon Larrañaga

Day 12 of 30DayMapChallenge: « 2125 » (previously).

Vidaller et al. (2021) indicate that Pyrenean glaciers are in a clear imbalance with the regional climate and will likely disappear in the next few decades.

library(dplyr)
library(ggplot2)
library(glue)
library(sf)
library(elevatr)
library(rnaturalearth)
library(rnaturalearthhires)
library(osmdata)
library(terra)
library(ggspatial)
library(ggnewscale)
library(ggrepel)

sf_use_s2(FALSE)

Data

pyrenees <- getbb("Pyrénées", format_out = "sf_polygon")$polygon

if (!file.exists("elevation_pyrenees.tif")) {
  get_elev_raster(pyrenees, z = 9) |> 
    writeRaster("elevation_pyrenees.tif")
}

elevation_pyrenees <- rast("elevation_pyrenees.tif") 
elevation_pyrenees[elevation_pyrenees <=0] <- NA

# map background
world <- ne_countries(scale = 10) |> 
  st_intersection(elevation_pyrenees |> 
                    st_bbox() |> 
                    st_as_sfc())

slope <- terrain(elevation_pyrenees, "slope", unit = "radians")
aspect <- terrain(elevation_pyrenees, "aspect", unit = "radians")
hillshade <- shade(slope, aspect, angle = 45, direction = 315, normalize = TRUE)

Map

# we create a void layer to train the scale and have a legend 
glaciers <- st_polygon() |> 
  st_sfc() |> 
  st_sf() |> 
  st_set_crs("EPSG:4326") |> 
  mutate(glaciers = NA_character_)

ggplot() +
  geom_sf(data = world, fill = "#c4c4c4", color = "#c4c4c4") +
  layer_spatial(hillshade) +
  scale_fill_distiller(palette = "Greys", guide = "none", 
                       na.value = "transparent") +
  geom_sf(data = world, fill = NA, color = "#333333") +
  new_scale_fill() +
  geom_sf(data = glaciers, aes(fill = glaciers)) +
  scale_fill_brewer(palette="RdYlBu", na.value="blue") +
  geom_text_repel(data = world, aes(label = sovereignt, geometry = geometry), 
                  stat = "sf_coordinates", color = "#333333",
                  bg.colour = "#ffffffaa", bg.r = .2, alpha = 0.4) +
  coord_sf() +
  labs(title = "Pyrenean glaciers",
       subtitle = "2125",
       x = "", y = "",
       caption = glue("https://r.iresmi.net/ - {Sys.Date()}
                       Elevation data from //
                       https://registry.opendata.aws/terrain-tiles
                       Natural Earth")) +
  theme_minimal() +
  theme(plot.caption = element_text(size = 6, 
                                    color = "darkgrey"),
        legend.position = "bottom",
        legend.text = element_blank())

Figure 1: Map of Pyrenean glaciers in 2025

A sad map for sure…

References

Vidaller, I., J. Revuelto, E. Izagirre, F. Rojas-Heredia, E. Alonso-González, S. Gascoin, P. René, et al. 2021. “Toward an Ice-Free Mountain Range: Demise of Pyrenean Glaciers During 2011–2020.” Geophysical Research Letters 48 (18): e2021GL094339. https://doi.org/10.1029/2021GL094339.