Water Point Accessibility by Cédric Scherer Data Visualization Design

The set of 31 voronoi maps show water points monitored over time by governments and development partners for indiviual countries.

The data is collected by the Water Point Data Exchange (WPDx) which aims to unlock the potential of water point data to improve decision-making and increase rural water access.

Voronoi maps are based on the minimal distance needed to reach a landmark—here reported water points—by using tessellation techniques that partition a plane into regions closest to these points. The darker the color of the region, the
closer it is to the country's middle point. This variable, known as centroid, was not the one I originally planned mapping color to—however, while it helps to access in which region of the Voronoi cell the water point is located, it also resulted in a wonderful gradient in case of countries with many, more homogeneously distributed water points and a strong contrast in case of only a few reported points. These differences in color patterns can help to disentangle how many water points a country has (reported) and how heterogeneously they are distributed.
The coloring of the background circle indicates the proportion of improved versus unimproved water sources: the more intense the blue, the more improved water points; grey means no information.

The maps were created as a personal contribution to the #TidyTuesday challenge in June 2021 . The maps were completely created in R with ggplot2. The code and image are publicly available on GitHub. All 31 different maps are featured in the Bejance project page.