Mapping Environmental Health: Water and Sanitation


This lab draws on Yale’s Environmental Performance Index (EPI) data in a new light. Instead of analyzing the data to describe differences between countries via histograms and tables, it was used for spatial analysis through GIS (Geographic Information Systems). The spreadsheet EPI data is displayed in this context as an interactive map. In the descriptive statistics lab, different country’s scores (0 – 100), were used to compare environmental health or vitality performance between two different countries. As described in the descriptive statistics lab (link above), a country’s score depends upon how well a country achieves a policy goal for improvement on safe drinking water, for example. In this lab, we chose one issue pertaining to environmental health or vitality and compared performance on this issue by creating maps of data from 2007 and 2015. I chose to map global environmental health scores of water and sanitation (drinking water quality) to visually compare any changes that occurred between 2007 and 2015.


Upon setting up an account with ArcGIS, we downloaded a zip file containing a geometric shapefile of all the world’s countries. We also downloaded the 2007 and 2015 EPI data to utilize their global scores of water sanitation. Upon downloading all the data, we created a new GIS map and imported the aforementioned files. Water sanitation was analyzed via the ISO country codes and the 2007/2015 EPI scores to import a combined layer for maps of the world in 2007 and 2015.

To compare water sanitation between the world’s nations, drinking water quality was chosen as a GIS layer. On the map, darker shades of blue indicate higher scores and lighter shades indicate lower EPI scores. Upon completing the map, it was made public and embedded into this post as seen below.


Figure 1 represents global EPI water sanitation scores in the year 2007. The darker the color, the higher the score. The legend displayable in the upper lefthand corner indicates that a country with a score below 41 will be white and a country with a score above 93 will be shown as the darkest blue. All in between values fall on the appropriate shade of blue, map below.

Figure 1

[iframe width=”1000″ height=”800″ frameborder=”0″ scrolling=”no” marginheight=”0″ marginwidth=”0″ title=”Environmental Health 2007: Water” src=”//,-88.3263,180,89.3823&zoom=true&previewImage=false&scale=true&legend=true&disable_scroll=true&theme=light”]

Figure 2 represents global EPI water sanitation scores for the year 2015. The color scheme and value analysis is the same as in figure 1. However, the legend differs as countries with a score of 50 or below are shown as white and countries with scores of 95 or above are shown as darkest blue.

Figure 2

[iframe width=”1000″ height=”800″ frameborder=”0″ scrolling=”no” marginheight=”0″ marginwidth=”0″ title=”Environmental Health 2015: Water” src=”//,-71.6105,180,83.7244&zoom=true&previewImage=false&scale=true&legend=true&disable_scroll=true&theme=light”]


On a global scale, certain regions clearly perform better than others regarding water sanitation. In general, the continents of Europe, North America and Australia have the greatest proportion of scores over 93 in 2007. This trend remains in the year 2015 with these continents continuing to lead with regards to achieving policy goals of water sanitation. On the other hand, the northern portion of South America, Asia and Africa have the highest proportions of countries with water sanitation scores falling below global averages. Struggling regions persist from 2007 to 2015.

Although it may appear as if no change has occurred with regards to global water sanitation between the years of 2007 and 2015, there has been a general increase in scores. This can be seen when one compares the legends of figures 1 and 2. The low score needed for a country to appear as white increased from 41 in 2007 to 50 in 2015. Also, the high score needed for a country to show up as darkest blue increased from 93 in 2007 to 95 in 2015. Although incremental, this trend implies that global water sanitation is generally improving over time on a country to country basis. However, we still have a long way to go before all have access to clean drinking water. As countries develop, their scores will continue rise but inequality regarding water sanitation will persist.


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