Tag: radial

Circular Zinc Flows

While some were indulging in an extended spring cleaning (this year labeled ‘quarantine cleaning’) I decided to take on some of the hard disks sitting on my desk.

These circular zinc flow diagrams from 2011 survived the cleaning and are getting a new life here on the blog. They are more or less two versions of the same diagram, apparently with a Sankey diagram in mind.

The first is a top view and shows zinc flows in the economy (U.S. or world? … sorry, but I don’t have the accompanying text any more). Flows are in millions of tonnes (Mt) in 1996. The second one has the same numbers, but adds a 3D perspective…

Some tricky issues here: The ‘zinc in products’ stream of 8.1 Mt narrows down to zero, as the zinc sits in products, from where it later might be released into the cycle again. This does not help the attempt to draw them in a circle (to associate circularity of zinc flows). As a consequence the streams are not to scale (compare, for example the 0,8 Mt scrap feed flow right next to the 6,6 Mt flow for zinc from mines). The 3D perspective and the shadow effect don’t help in any way here…

Check out some more Sankey diagrams with the tag ‘circular’ and this post on radial Sankey diagrams.

3D circular Sankey ugliness

You might remember the radial Sankey diagrams “invented” by Visio guy (here). This 3-D version below left me speechless… I hope the guys at junkcharts dedicate a critical evaluation to it….


(view the original diagram here)

This is from EUROFER (The European Confederation of of Iron and Steel Industries) and shows steel flows in fifteen European countries (EUR-15) in million metric tons. Values are for 2004. The grey area is supposed to represent steel accumulated in capital goods (machinery, buildings, …) over a certain life time.

Whooo woah, that’s a merry go round, I feel dizzy already!

VisioGuy invents Radial Sankey Diagrams

Chris the VisioGuy recently came up with Radial Sankey Diagrams. Although he didn’t seem to be sure if there is a “need for radially-oriented Sankey diagrams”, the commentators of his post immediately came up with ideas: use for rotating or radiating processes, cigarette rolling, recursive industrial processes, reinvestments, and so on… even stellar nuclear reactions were mentioned.

This is the ‘Everything Radial’ Circular Sankey Diagram

… and this is the ‘Tangential Fly-off’ Circular Sankey Diagram

One concern seems to be that the proportional arrow magnitude doesn’t work that well, since the human eye perceives the arrow area rather than thickness in such a circular Sankey diagram.

Thanks VisisoGuy for this contribution to the big basket of Sankey diagrams

What goes up, must come down!

For most Sankey diagrams I find when browsing the web, a ‘left-to-right’ or ‘bottom-to-top’ orientation prevails. ‘Top-to-bottom’ is less common, but there are also examples like this one.

A rather untypical shape for a Sankey diagram has been up on the German page of the e!Sankey webpage.

It shows the energy balance for a pumped storage power plant as a curved shape, with the energy input at the left leg, and the energy that can be recovered (77.3%) at the right one.

Energy is stored “in the form of water, pumped from a lower elevation reservoir to a higher elevation. Low-cost off-peak electric power is used to run the pumps. During periods of high electrical demand, the stored water is released through turbines. Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest. Pumped storage is the largest-capacity form of grid energy storage now available.” (Wikipedia)

I searched for the original Sankey diagram in the source given (Quaschning 2007) and found this text with the diagram in chapter 6.1.2. That diagram already featured the curvy shape, and has just been reproduced similarly.

The use of the curve layout seems justified here. The author chose it to point out the difference in altitude. The upper basin is at the apex of the curve. Water pumped up from the lower basin requires energy, which can partly be recovered when the water runs down again.

What goes up…