Visual Design Type: Choropleth. It shows the commission date of the oldest power plant in each country.
Name of Tool: Tableau.
Countries: This is a global chart including every country with suitable data.
Year: This chart shows the oldest plants in each country, the years range from 1896 to 2018.
Visual Mappings: The Longitude and Latitude of each plant was used to map them to their country. The commission date of the oldest plant in each country is mapped to its colour. If a power plant is very old, then the country is yellow. If a country has relatively new power plants, then the country will be coloured green.
Unique Observation: Countries within the continent of Africa seem to have relatively new power plants when compared to the rest of the world. This may be due to the fact that there are many developing countries within Africa.
Data Preparation: I had to filter out all but one power plant for each country. The only power plant that was being taken into account is the oldest one. This involved creating a calculated field in Tableau and filtering out any that didn’t satisfy the condition.
My question is as follows: is there a better colour scheme that could be used to improve the readability of the chart?
Along with this, any other suggestions as to how I could improve the visual design of the Choropleth would be greatly appreciated.