Tag: urban

Cape Town Water Use Sankey Diagram

From a post ‘Cape Town’s water crisis : Towards a more water secure future’ on the Future Cape Town blog comes this Sankey diagram on the water use in the city of Cape Town (South Africa).

The author of the diagram, Rebecca Cameron, is with MCA Urban and Environmental Planners and looks at how Cape Town could transition towards a more water secure future. This Sankey diagram was originally published in her article Cameron, R and Katzschner, T. 2016. The role of spatial planning in enhancing Integrated Urban Water Management in the City of Cape Town. South African Geographical Journal. 99(2), pp. 196 – 216.

Absolute flow values are not given in this version of the Sankey diagram. Flows are in million cubic metres per year (Mm³/a). Water from five different sources outside the municipality feed the city of Cape Town, as well as five sources within the city. A breakdown of water supplied by the municipal water works is shown. Additional color coding of the arows indicate water quality (dark green = sewage, light green = treated water).

The author explains:

“This diagram is helpful in that it places all aspects of the water system in to one diagram. Here, water supply, water use, wastewater treatment and stormwater have been considered as a single system where too often the urban water cycle is fragmented when addressed within different sectors. The arrows of flow follow a key to represent the quantity and quality of water. The size of the arrow of flow is proportionally indicative of the quantity of water that flows from one process to one another. The colour of the arrows indicates the quality of the water flow; this includes non-potable, potable, sewage, treated sewage, and treated sewage for reuse. This is important to represent as, to intervene in an urban water cycle, both quantity and quality of water must be considered and used appropriately to move towards a more efficient and sustainable water system.”

From the rivers most of the water goes to the ocean. Through evaporation and precipiation it (hopefully) replenishes the reservoirs again that feed the city (this last part not shown in the diagram).

Stuttgart City Energy Flows

The energy balance of the German city of Stuttgart has been mapped as a Sankey diagram.

This was part of the project ‘SEE Stuttgart’ (City with Energy Efficiency / “Stadt mit Energie-Effizienz”) and has been developed by Fraunhofer IBP research institute.

A vertical layout was chosen. Absolute energy flow quantities are not shown in this version of the diagram, but are available in the underlying study. In 2010 primary energy consumption in Stuttgart was 20.300 GWh.

The diagram is used to promote a better understanding of the consuming sectors in the city, and the types of energy used. The SEE project aims to reduce Stuttgart’s energy consumption by 20% in 10 years and to transition to non-fossil fuels.

Stuttgart has actually won a first prize in a competition for energy efficient cities in 2016. It is thus setting a benchmark for other German cities. The above Sankey diagram is featured in this promotional video (in German) [at 2:36] and also briefly in this video (in German) [at 0:48] by IBP Fraunhofer.

A high resolution version of the Sankey diagram can be found here.

Amsterdam Energy System Visualized

Tom Van Heeswijk and Changsoon Choi, landscape architecture master students at Wageningen University in the Netherlands have created the below “preliminary Sankey diagram of the Amsterdam energy system”. This is part of the larger project URBAN PULSE described on the research page of the NRG lab website.

Only the top part of a larger Sankey diagram is seen here, the bottom part with fossil fuels apparently cropped. No units or figures shown, so just a schematic visualization.

Nevertheless some interesting features: in contrast to many other Sankey diagrams, nodes are not depicted with outlines but shown as gaps with their name. Electricity is highlighted as red bands while all other flows have a single-hatching fill pattern.

Beauty of simplicity…

Participatory Urban Metabolism Information System

Interesting project described in the blog article ‘Understanding your city by understanding its flow: towards Participatory Urban Metabolism Information Systems’ by Sven Eberlein of the Ecocitizen Worldmap Project.

This is a participatory approach where young citizens track the water flows in their city in a crowd-mapping approach. The data is visualized as Sankey diagram (here called MetaFlow diagram). Pilots were carried out in Casablanca and Cairo.

This project is somehow linked to Sebastian Moffat’s activities I have featured in a blog post back in 2008.

This seems to be the result from either the Casablanca or the Cairo field work. Great colorful Sankey flow diagrams. Judging from the photos in the blog post, working with the local community seems to have been fun. The participatory approach is emphasized (Sven calls this a ‘Participatory Urban Metabolism Information System (PUMIS)’).

More Sankey diagrams can be seen in the original blog post.

From Sankey diagram to infographic

I really liked Will Stahl-Timmins’ article on how he developed an infographic on energy consumption in a city.

Will’s blog is called ‘Seeing is Believing’ and his central claim is that information graphics are “the visual transformation of data into understanding”. I agree: infographics are more than just a diagram and labels. They are much more “visual” and their design elements add to a better understanding. Diagrams convey data, infographics convey information. Typically they also have a broader audience: you would find a diagram in a scientific paper, but an infographic in a daily newspaper.

The article ‘Visualising city energy policies’ gives a very good insight into the reasoning of an infographer/designer when creating an infographic. Will describes how he started out from an ordinary Sankey diagram, to get to an infographic step-by-step. This involved studies of different alternatives, sketches on paper, discussions with colleagues, presentations, and many different versions of the infographic in Illustrator…

He experimented with an isometric or what he calls a “pseudo-3D” perspective, but also discovered some shortcomings in using them.

Crossing arrows were an issue. So were the stacked nodes (cubes) that hid parts of flows and were difficult to label.

The “intermediate” outcome of his meticulous work was the below infographic. It seemed to have been a long learning process to achieve this result.

Will went on to include feedback he had gotten from fellow researchers, and decided to add more information on imported energy. At the same time he had to reduce the level of detail. This is the final infographic.

Good work, I think! The resulting infographic is not a genuine Sankey diagram anymore. There are only three arrow widths left, quantities are clustered in these groups. But as I said, an infographic has a different purpose.

It is not mentioned clearly how this infographic will finally be used, and who the target audience is. I imagine it will be used as an illustration in a brochure that summarizes the findings of the URGENCHE project, but to a wider, non-technical audience.

Make sure you read the full blog post at ‘Seeing is Believing’.

SOPA 2013 Award: Wiring the City

Simon Scarr has won a SOPA 2013 Award for Excellence in Information Graphics (PDF, see p. 13) with this Sankey diagram titled ‘Wiring the City’ originally created for the South China Morning post.

It shows energy flows and energy use in Hong Kong

On his blog he writes: “… we took a look at Hong Kong’s power consumption. Who uses all the electricity in our city and what is it used on? (…) Data set was provided by the government’s Electrical and Mechanical Services Department. (…) This type of chart is known as a Sankey diagram. The thickness of each line reflects a value. In this case, an amount of electricity in terajoules. All of the lines add up to give subtotals and totals by users (grey) and end use (coloured).”

Congratulations, Simon!

A day in the life of… Victor Hugo

I admire architects for their visionary ideas, for being able to transcend established limits, for pushing things beyond the common … at least when still in early phases of a project.

Victor Hugo Azevedo’s blog is called ‘La Ville Radieuse’ (The Radiant City) after a concept by Le Corbusier. It has all kinds of architectural stuff. By mere coincidence I discovered the following Sankey diagram he did in 2011 as class assignment on energy flows…

“This time we were asked to trace the energy flow that directly affect us. I traced the beginning of a common day during my summer in the city of Manaus Brazil. The following diagram shows how the larger infrastructure shape my routine.”

This looks at first sight like one of the classic ‘national energy flow’ Sankey diagrams with fuels (production) on the left, distribution and consumption on the right. But this is only partly true. Look at the right part where the energy flows stack and have a vertical time line.

“The next diagram is nothing more than a closer look into one of the ends of the diagram, which is my own routine on a four hour span (from 7AM to 10AM on a regular weekday in June)”

So forget about scale and units here … this is a concept diagram! The Sankey diagram links an individual’s consumption patterns with the bigger picture, thus stressing everybody’s personal share and responsibility in energy consumption (and the possibility to take action). Kudos for this idea!

Apart from that it is of course a fancy 3D rendering, and I love the rotation and close-up of the morning routine. Make sure you post a comment directly at Victor’s post, if you like it as much as I do!

Note: Somewhat related, check out Molly Eagan’s ‘Where is Petroleum in our Daily Lives’ here.