Graphing Wastewater in China

Cody Steele 02 September, 2015

Map of ChinaNewsweek's recent article, The Environmental Disaster in Your Closet, led me (through Greenpeace's Detox Catwalk) to an interesting new data set on the web. Since I like public data, I thought I'd share some graphs I made from the Chinese Institute for Public and Environmental (IPE) affairs global online platform. The IPE website describes that their goal is "to expand environmental information disclosure to allow communities to fully understand the hazards and risks in the surrounding environment, thus promoting widespread public participation in environmental governance," which sounds great to me. Minitab can make it easy to see patterns in different groups of data over time, including environmental data by region across China.

Total Wastewater is Highest in Guangdong

Because the IPE’s aim is to expand environmental information disclosure, it has a lot of environmental data. The data sets exist at a number of different levels, including individual facilities and river basins. I started out looking at total wastewater by region (8/31/2015). Here’s what that looks like over time:

Total wastewater is highest in Guangdong

Most of the lines are close together on this scale, but the top one stands out. This is the line for Guangdong. Because I hadn’t acknowledged the depth of my ignorance about China, I had to do some research to find out whether there was an explanation for why this region would stand out in terms of their wastewater discharge.

Looking a Little Deeper

Turns out that Guangdong was the most populous region in China in 2013 and the region with the highest Gross Domestic Product (GDP) in 2009. Either factor could contribute to the amount of wastewater from a region. It turns out that the association between a region’s population in 2013 and the amount of wastewater recorded in the IPE database is fairly strong, which could be one explanation for why Guangdong has so much wastewater. Of course, we'd have to look more closely to establish a causal relationship (See mistake 3). Because the association between population and total wastewater is strong, it’s not surprising that a graph of wastewater per person looks different from the graph of total wastewater. While Guangdong is still one of the higher lines, it’s Shanghai that is the leader in per capita wastewater (using the 2013 population as representative for the years 2004 to 2013).

Shanghai has the highest amount of wastewater per person

If you look at the amount of wastewater divided by GDP, it looks like Guangxi will stand out, but a large drop in 2011 puts it closer to the rest of the lines.

Total wastewater declined more in Guanxi in 2011 than in most other regions.

So Many Graphs, So Little Time 

The amount of transparency in society is increasing all the time. The things that you can learn from that data are increasing too. Graphical analysis that Minitab provides can give you quick answers to difficult questions about your data. To see more, take a look at Which graphs are included in Minitab? for an overview of different ways you can examine your data.