Cartography Assignment

R GIS

Maps for life expectacy in Africa and South America

Grace Kumaishi, Julia Parish https://github.com/juliaparish
2021-10-15

This cartography project was completed as an assignment for my Master’s program course, Environmental Data Science 233: Spatial Analysis. It was collaboration with G. Kumaishi.

Project Goal

Create a map of life expectancy for South America and Africa.

Step One

Create two separate maps for life expectancy data of South America and Africa using spData and tmap.

Life Expectancy in Africa:
Show code
### Africa ###

world_africa <- world[world[["continent"]] == "Africa", ] # create a subset of the world dataset of just the African continent

lifeexp_africa <- tm_shape(world_africa) + # store map in order to combine
  tm_polygons(col = "lifeExp", # select life expectancy data
            palette = "YlOrBr", # Yellow Orange Brown color palette from RColorBrewer
            style = "pretty", # familiar GIS discrete options available such as quantile, equal, jenks, etc.
            title = "Life Expectancy (years)*", # legend title lives within tm_polygons
            textNA = "No Data") +   # converted "Missing" legend default to "No Data"
  tm_layout(inner.margins = c(0.1, 0.1, 0.1, 0.1), # margins between 0-1 (bottom, left, top, right)
            legend.title.size = 1,
            legend.text.size = .8,
            bg.color = "lightblue", # background color
            title = "Africa") + # map title lives under tm_layouts
  tm_compass(type = "4star", # other compass styles available
            show.labels = 1, # specifies compass label options
            size = 3,
            position = c("right", "top")) +
  tm_credits("Life expectancy data for the\nAfrican continent uses 5-year\nclassification breaks.\nSource: SpData \n \n*Note that the color scale differs\nbetween continents.", # credit data source including github link; \n creates text break
            size = .5, # can't figure out how to make size bigger...
            position = c("right", "bottom"), 
            align = "right", # only applicable if using multiple lines
            width = NA) # 1 is the whole map width, NA is determined by width of text

lifeexp_africa
Map of life expectancy for African countries. Life expectancy is visualized with five-year increments.

Figure 1: Life Expectancy in Africa

Life Expectancy in South America:
Show code
### South America ###

world_sa <- world[world[["continent"]] == "South America", ] # create a subset of the world dataset of just the South American continent

lifeexp_sa <- tm_shape(world_sa) + # store map in order to combine
  tm_polygons(col = "lifeExp", # select life expectancy data
            palette = "YlOrBr", # Yellow Orange Brown color palette from RColorBrewer
            n = 5, # specify number of breaks
            style = "pretty", # familiar GIS discrete options available such as quantile, equal, jenks, etc.
            title = "Life Expectancy (years)*", # legend title lives within tm_polygons
            textNA = "No Data") + # converted "Missing" legend default to "No Data"
  tm_layout(inner.margins = c(0.1, 0.25, 0.1, 0.25), # margins between 0-1 (bottom, left, top, right)
            legend.position = c("right", "bottom"), 
            legend.title.size = 1,
            legend.text.size = .8,
            bg.color = "lightblue", # background color
            title = "South America") + # map title lives under tm_layouts
  tm_compass(type = "4star", # other compass styles available
             show.labels = 1, # specifies compass label options
             size = 3,
             position = c("right", "top")) +
  tm_credits("Life expectancy data\nfor the South American continent uses\n2-year classification breaks.\nSource: SpData \n \n*Note that the color scale differs\nbetween continents.", # credit data source including github link; \n creates text break
             position = c("left", "bottom"), 
             align = "left",
             size = .5) + 
  tm_credits("", # explain varying color scales b/w two continents; \n creates text break
             position = c("right", "bottom"), 
             align = "right",
             size = .3)
  
lifeexp_sa
Map of life expectancy for South American countries. Life expectancy is visualized with two-year increments.

Figure 2: Life Expectancy in South America

Step Two

Combine the two maps using tmap_arrange to compare and contrast life expectancy rates.

Life Expectancy in South America and Africa:*
Show code
combined_lifeexp <- tmap_arrange(lifeexp_sa,lifeexp_africa) # combine the two life expectancy maps using tmap_arrange

combined_lifeexp
A figure comparing life expectancy between South America and Africa. South America is visualized with two-year increments, while Africa is visualized with 5-year increments.

Figure 3: Fig 3: A Comparision of Life Expectancy between South America and Africa

Conclusion

This project was to practice creating maps in R using sf, tmap, and spData packages.

Citation

For attribution, please cite this work as

Parish (2021, Oct. 15). Julia Parish: Cartography Assignment. Retrieved from juliaparish.github.io/posts/2021-10-15-lifeexpectancy/

BibTeX citation

@misc{parish2021cartography,
  author = {Parish, Grace Kumaishi, Julia},
  title = {Julia Parish: Cartography Assignment},
  url = {juliaparish.github.io/posts/2021-10-15-lifeexpectancy/},
  year = {2021}
}