Click the Original, Code and Reconstruction tabs to read about the issues and how they were fixed.

Original


Source: Butler, R. A. (2020)


Objective

The purpose of this pie-chart was to demonstrate the percentage of Amazon forest which has been cut down according to the Amazonia countries. The data used was obtained from measurement using various satellite data. The targetted audience was those who can determine pattern or trends through visuals but they somewhat fails to do so.

The three main issues with the visualisation chosen are as follows:

  • a pie chart itself is subject to controversy as it tends to deceive
  • this pie chart is the result of a standard Excel output which explain the redundancy of the colour
  • the smaller forest share losses are not specify on the pie chart but need to go through the legend to calculate the percentages

Reference

Code

The following code was used to fix the issues identified in the original.

library(ggplot2)
hectares <- c(17784762,2269636,1654462,863678,273739,213491,109875,103967,35990)
Percent <- (hectares/sum(hectares))*100
Amazon <- data.frame(Country = c("Brazil", "Bolivia","Peru", "Colombia", "Venezuela","Ecuador","Guyana","Suriname","French Guiana"),Perc = round(Percent,2))

bar <- ggplot(data = Amazon, aes(group = 1,x=Country,y = Perc))+ geom_bar(stat = "identity", fill = "darkseagreen") + 
  theme(plot.title = element_text(hjust = 0.5, size = 18),panel.grid.minor = element_blank(),panel.background = element_blank(), axis.line = element_line(colour = "black"))+
  geom_text(aes(label = paste(Perc,"%",sep="")),color="black",vjust=-0.3,size=3.5) +
  labs(title = "Share of Amazon forest loss by country, 2010-2017",x ="",
       y = "loss %")

Data Reference

  • Hansen, M. C., P. V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S. V. Stehman, S. J. Goetz, T. R. Loveland, A. Kommareddy, A. Egorov, L. Chini, C. O. Justice, and J. R. G. Townshend. 2013. “High-Resolution Global Maps of 21st-Century Forest Cover Change.” Science 342 (15 November): 850–53. Data available on-line from: http://earthenginepartners.appspot.com/science-2013-global-forest.

Reconstruction

The bar plot below fixes the issues which we encountered with the original pie-chart.