Casiquiare – r.iresmi.net

A photo of Piedra de Culimacare on the Rio Casiquiare — Piedra de Culimacare on the Rio Casiquiare – CC-BY-NC-ND by Carsten ten Brink

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

Do you know you can circumnavigate the Guiana shield? There is a river, the Rio Casiquiare, that connects the Orinoco and the Amazon basin! If you need a map for your next adventure, in the “footsteps” of Alexander von Humboldt, here it is…

We pick the OpenStreetMap ID of the river relations (e.g.: https://www.openstreetmap.org/relation/2295651), make a data.frame of the rivers geometry and plot it.

library(tidyverse)
library(sf)
library(rnaturalearth)
library(osmdata)
library(ggspatial)
library(ggrepel)

countries <- ne_countries(scale = 50, returnclass = "sf") 

rivers <- tribble(~name,            ~relation,
                  "Rio Casiquiare", 275909,
                  "Orinoco",        1083284,
                  "Rio Negro",      275660,
                  "Rio Amazonas",   2295651) |> 
  mutate(geometry = map(relation, \(r) paste0("relation/", r) |> 
                                     opq_osm_id() |> 
                                     opq_string () |> 
                                     osmdata_sf () |> 
                                     pluck("osm_lines", "geometry") |> 
                                     st_union() |> 
                                     st_geometrycollection())) |>
  st_sf(crs = "EPSG:4326")

ggplot() +
  geom_sf(data = countries, color = "gray80", fill = "gray95") +
  geom_sf(data = rivers, aes(color = name), linewidth = .8, key_glyph = "smooth") + 
  geom_text_repel(data = countries |>
                    filter(adm0_a3 %in% c("BRA", "GUY", "VEN", "SUR", "COL", "PER")), 
                  aes(label = name, geometry = geometry), 
                  stat = "sf_coordinates", size = 2.5) +
  scale_color_manual(name = "river",
                     values = c("Rio Casiquiare" = "firebrick3",
                                "Orinoco"        = "cyan4",
                                "Rio Negro"      = "gray10",
                                "Rio Amazonas"   = "burlywood2")) +
  coord_sf(xlim = c(-81, -36), ylim = c(-20, 12)) +
  labs(title = "Circumnavigating the Guiana shield",
       caption = "Approximate scale\nData: Openstreetmap contributors\nBasemap: Natural Earth\nhttps://r.iresmi.net/",
       x = "",
       y = "") +
  annotation_scale(height = unit(1, "mm")) +
  theme(panel.background = element_rect(fill = "azure"),
        panel.grid = element_line(color = "azure2"),
        legend.key = element_rect(fill = NA),
        plot.caption = element_text(size = 6))

--- title: "Casiquiare" description: "Day 12 of 30DayMapChallenge" author: "Michaël" date: "2023-11-12T08:00:00" date-modified: last-modified categories: - R - 30DayMapChallenge - spatial - datavisualization - OSM draft: false freeze: true editor_options: chunk_output_type: console chunk_output_type: console execute: eval: true --- [![Piedra de Culimacare on the Rio Casiquiare -- CC-BY-NC-ND by Carsten ten Brink](images/53020604615_f719b40435_b.jpg){fig-alt="A photo of Piedra de Culimacare on the Rio Casiquiare"}](https://flic.kr/p/2oMfsxr) Day 12 of [30DayMapChallenge](https://30daymapchallenge.com/): « South America » ([previously](/#category=30DayMapChallenge)). Do you know you can circumnavigate the [Guiana shield](https://en.wikipedia.org/wiki/Guiana_Shield)? There is a river, the [Rio Casiquiare](https://en.wikipedia.org/wiki/Casiquiare_canal), that connects the Orinoco and the Amazon basin! If you need a map for your next adventure, in the "footsteps" of [Alexander von Humboldt](https://en.wikipedia.org/wiki/Alexander_von_Humboldt), here it is... We pick the OpenStreetMap ID of the river relations (*e.g.*: <https://www.openstreetmap.org/relation/2295651>), make a `data.frame` of the rivers geometry and plot it. ```{r} library(tidyverse) library(sf) library(rnaturalearth) library(osmdata) library(ggspatial) library(ggrepel) countries <- ne_countries(scale = 50, returnclass = "sf") rivers <- tribble(~name, ~relation, "Rio Casiquiare", 275909, "Orinoco", 1083284, "Rio Negro", 275660, "Rio Amazonas", 2295651) |> mutate(geometry = map(relation, \(r) paste0("relation/", r) |> opq_osm_id() |> opq_string () |> osmdata_sf () |> pluck("osm_lines", "geometry") |> st_union() |> st_geometrycollection())) |> st_sf(crs = "EPSG:4326") ``` ```{r} #| dev: png #| fig-width: 7 #| out-width: "100%" #| dev.args: #| bg: transparent ggplot() + geom_sf(data = countries, color = "gray80", fill = "gray95") + geom_sf(data = rivers, aes(color = name), linewidth = .8, key_glyph = "smooth") + geom_text_repel(data = countries |> filter(adm0_a3 %in% c("BRA", "GUY", "VEN", "SUR", "COL", "PER")), aes(label = name, geometry = geometry), stat = "sf_coordinates", size = 2.5) + scale_color_manual(name = "river", values = c("Rio Casiquiare" = "firebrick3", "Orinoco" = "cyan4", "Rio Negro" = "gray10", "Rio Amazonas" = "burlywood2")) + coord_sf(xlim = c(-81, -36), ylim = c(-20, 12)) + labs(title = "Circumnavigating the Guiana shield", caption = "Approximate scale\nData: Openstreetmap contributors\nBasemap: Natural Earth\nhttps://r.iresmi.net/", x = "", y = "") + annotation_scale(height = unit(1, "mm")) + theme(panel.background = element_rect(fill = "azure"), panel.grid = element_line(color = "azure2"), legend.key = element_rect(fill = NA), plot.caption = element_text(size = 6)) ```