Air pollution in Beijing, with orange alerts and high health risks made the news (again) recently.

One measure discussed to reduce pollution levels is to issue a partial ban for cars on the streets. This would certainly reduce some of the pressure, however, I am not quite sure whether this would significantly help improve the situation.

Looking at this 2005 energy flow Sankey diagram for China from World Resources Sim Center, one notices that the largest chunk of energy produced in China is from coal.

The energy from coal consumed in 2005 (purple boxes) was seven times higher than the energy consumed in the transportation sector (1.450 million tonnes of coal equivalent vs 230 million tonnes of coal equivalent, if I interpret this correctly). That is without counting losses that occur both at power stations as well as in vehicle engines.

Of course one might argue that traffic probably has risen enormously since 2005. I checked the latest available data for China (2011) at the International Energy Agency (IEA) website where you can access the national energy flow diagrams for more than 100 countries.

It confirms that both coal and petroleum consumption have risen, but coal is still predominant. Transportation makes up for “only” roughly 200 Mtoe (Millions of tonnes of oil equivalent) out of 1644 Mtoe final consumption, while the significant consumption is in industry and ‘other’ (probably private home heating).

So, even if burning of coal and gasoline has different levels of pollution (e.g. through efficient filtering technolgy), my guess is that the main reason for the smog in China are the coal-fired power plants and industrial furnaces. Reducing vehicle traffic will not lead to reduced coal-burning.

Anyone has data on GHG emissions from different sources in China? (preferably as a Sankey diagram….).

Hop Shing Engineering Co. Ltd, a Hong Kong based firm markets their services using this Sankey diagram (heat recovery, cogeneration)

Always nice to see Sankey diagrams in Chinese.

Phosporus in the natural environment and the food chain has been a topic of several posts on my blog. So it didn’t come as a surprise to find yet another diagram on phoshphorus flows over at Nels’s MFA Diagram blog (one of the blogs I follow closely, see blogroll).

MFA diagrams have their focus on the nodes and the build-up of stocks. Sometimes they get a touch of Sankey diagram with the arrows having different magnitudes. The MFA diagram below is for phosphorous flows in China 2008 (original source: Min Qiao, Yuan-Ming Zheng, Yong-Guan Zhu, 2011. Material flow analysis of phosphorus through food consumption in two megacities in northern China). Values are in tonnes.


(click image to enlarge)

We can detect arrows with three different brush widths (my guess is 1px, 2px and 4 px), each standing for a value range into which the actual flow quantity falls. This may, however, bes somewhat misleading when having a quick glance at the diagram.

I quickly “translated” the above diagram to a Sankey diagram with flow values being actually to scale.


(click image to enlarge)

Here it is quite clear where the major phosphorus flows are located (from food production via urban consumption to sewage treatment plant and solid waste disposal: 2923 out of 5374 tons end up here). The other flows are comparatively small, with the phoshporous flow going directly to the aquatic system worth a mention. Two small flows in the center of the diagram are negligible, they are in fact so tiny in comparison to the major flows that they even don’t show up (or just as a hairline) here.

I have therefore added a minimum width of 1 px for small flows so that the annual 17 tons from urban consumption and the 1.9 tons from rural consumption to the solid waste disposal are at least visible (albeit not to scale with the other flows any more).


(click image to enlarge)

Final phosphorous sinks are solid waste disposal (landfill?) and the aquatic system.

Carl-Johan Skoeld of China-based strategic advisory firm Stenvall Skoeld & Company presented the following Sankey diagram in his recent post on ‘How a 31-year old Shanghai office worker spends his money’.


(Stenvall Skoeld & Company via ChartPorn)

This is a fine sample of a Sankey diagram that merits some more explanation:
In fact, these are two combined Sankey diagrams. The overall sum of 10,000 RMB income breaks down to some 25% taxes, 19% savings and 56% spendings (consumption). The Sankey arrow representing the disposable income is then zoomed to allow for more detail to be seen. Hence the Sankey arrows in the left part of the diagram are not the same scale as the ones on the right. The arrows branching out to the top are considered “necessities”, while the one that go downwards represent “discretionary spendings”. Circles at the end of the arrow show the amount in Chinese currency. As the author points out, “this example is from one of the respondents and not an average of all respondents.”

Below is a Sankey diagram representing the energy balance for the city of Urumqi in Northwestern China. This was elaborated in a Sino-German Project on ‘Meeting the Resource Efficiency Challenge in a Climate Sensitive Dryland Megacity Environment: Urumqi as a Model City for Central Asia’ and has been published in the Integrated Heating and Building Energy Efficiency Master Plan for Urumqi in 2010

The Sankey diagram doesn’t sport the energy unit, but the text comment says:

The 2007 energy balance of Urumqi shows that about 541 PJ of primary energy was consumed in the city, accounting for 28% of the Xinjiang total (1,927 PJ). Urumqi used 25% of Xinjiang’s coal, 50% of its oil, 12% of its natural gas, and 4% of its renewable energy, much of it in heavy industry. This results in high energy related per-capita CO2 emissions of 22 tonnes. In 2007, the city consumed 14.7 million tonnes of coal (approximately 51% of its primary energy supply) whereby 30% of the coal consumption was used for the heating of buildings.

A notice on scoop.it/visualdata led me to this fascinating video on visualnews. It shows the making of an infographic in two minutes or 3657 frames and is by Jess Bachmann for mint.com.

The central element of the infographic is a Sankey diagram on the trade flows between the United States and China (and to/from other countries).

it is interesting to see how Jess did every weighted arrow as a brush line with rounded head (the heads are neatly hidden behind the country maps, or capped at the other end). Each horizontal, vertical and curved segment is done individually.

In the YouTube comments of the long version of this video the author replied to one commenter: “After determining a metric, i.e 1 pixel width = $1M, I then stroked a line with the corresponding size brush. A $34M item would have a 34px width line. At one point you can even see a calculator popping up (0:55 into the video).

The long (7 minute) version has a lot more details on how the infographic comes to life. You can even see that Jess keeps saving his work from time to time…

Wow, what a hell lot of work – but the result sure looks gorgeous.

I calculated that Jess took more than 10h to complete this: 3657 frames, ten seconds between each frame = 36570 sec, 3600 seconds to an hour, makes 10.16 hours! I am just glad I have my Sankey diagramming software, so at least I don’t have to bother about brush sizes.

I really had doubts, whether I should present the following Sankey diagram I found on John Locke’s Gracefulspoon blog [aesthetic photos there, have a look!]. Finally decided to feature it, because I want to show the whole spectrum of application fields for Sankey diagrams, and I am trying to put my focus more on the graphical aspects of the diagram rather than the explicit content of the diagrams.

The Sankey diagram featured in this post is for “life support in an artifically closed system” or in other words, a prison cell. John explains:

“a sustainable prison cell unit for future Beijing. Because of their high population density, prisons are actually prime contenders for tests of renewable energy methods, such as waste to energy, and water recycling features. … each prisoner generates energy for their own confinement, but also send excess energy back to a central grid, acting like capacitors.”

The Sankey diagram has four interconnected “cycles”, each with their individual units: the energy flows (kWh), the water cycle (Litres), the waste cycle (kg), and food flows (lbs). The four subsystems thus must be interpreted relative to each other and not with their absoulute values. The main input that “feeds” the system is solar energy, the main output is recovered energy. Apart from a freshwater input flow and some comparatively small waste output flows (branching out vertically), the system seems fully closed. It is of course an idealistic assumption that prisoners can be fed solely on genetically modified micro-algae…

If you look at the Locke’s ‘Global Panopticon’ study project “conceived more as a sci-fi narrative”, let’s just hope that such ideas never turn reality.