Sankey diagrams are a type of

flow diagram Flow diagram is a collective term for a diagram representing a flow or set of dynamic relationships in a system. The term flow diagram is also used as a synonym for flowchart, and sometimes as a counterpart of the flowchart.Harris. (1999, p. 156 ...

in which the width of the arrows is proportional to the flow rate. Sankey diagrams can also visualize the energy accounts, material flow accounts on a regional or national level, and cost breakdowns. The diagrams are often used in the visualization of material flow analysis. Sankey diagrams emphasize the major transfers or flows within a system. They help locate the most important contributions to a flow. They often show conserved quantities within defined system boundaries.

History

Sankey diagrams are named after Irish Captain

Matthew Henry Phineas Riall Sankey Matthew Henry Phineas Riall Sankey (9 November 1853 – 3 October 1925) was an Irish-born engineer and captain in the Royal Engineers, known as the creator of the Sankey diagram. Biography Sankey was born at Nenagh in County Tipperary in 1 ...

, who used this type of

diagram A diagram is a symbolic representation of information using visualization techniques. Diagrams have been used since prehistoric times on walls of caves, but became more prevalent during the Enlightenment. Sometimes, the technique uses a three ...

in 1898 in a classic figure (see diagram) showing the energy efficiency of a

steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be ...

. The original charts in black and white displayed just one type of flow (e.g. steam); using colors for different types of flows lets the diagram express additional variables. Over time, it became a standard model used in science and engineering to represent heat balance, energy flows, material flows, and since the 1990s this visual model has been used in

life-cycle assessment Life cycle assessment or LCA (also known as life cycle analysis) is a methodology for assessing environmental impacts associated with all the stages of the life cycle of a commercial product, process, or service. For instance, in the case ...

of products. Minard

One of the most famous Sankey diagrams is Charles Minard's Map of Napoleon's Russian Campaign of 1812. It is a flow map, overlaying a Sankey diagram onto a geographical map. It was created in 1869, predating Sankey's first Sankey diagram of 1898.

Science

Sankey diagrams are often used in fields of science, especially physics. They are used to represent energy inputs, useful output, and wasted output.

Active examples

The United States Energy Information Administration (EIA) produces numerous Sankey diagrams annually in its ''Annual Energy Review'' which illustrate the production and consumption of various forms of energy. The US Department of Energy's Lawrence Livermore Laboratory maintains a site of Sankey diagrams, including US energy flow and carbon flow.

Eurostat Eurostat ('European Statistical Office'; DG ESTAT) is a Directorate-General of the European Commission located in the Kirchberg, Luxembourg, Kirchberg quarter of Luxembourg City, Luxembourg. Eurostat's main responsibilities are to provide stati ...

, the Statistical Office of the European Union, has developed an interactive Sankey web tool to visualise energy data by means of flow diagrams. The tool allows the building and customisation of diagrams by playing with different options (country, year, fuel, level of detail). The

International Energy Agency The International Energy Agency (IEA) is a Paris-based autonomous intergovernmental organisation, established in 1974, that provides policy recommendations, analysis and data on the entire global energy sector, with a recent focus on curbing car ...

(IEA) created an interactive Sankey web application that details the flow of energy for the entire planet. Users can select specific countries, points of time back to 1973, and modify the arrangement of various flows within the Sankey diagram. Ben Schmidt, an assistant professor of history at Northeastern University, created a Sankey diagram relating majors in college to eventual careers. Single Transferrable Vote example

References

External links

RAWGraphs
online open-source platform allowing the creation of Sankey diagrams
Scottish Executive
– Energy in Scotland: Supply and Demand
Irish Environmental Protection Agency
– Material Flow Accounts (MFAs) – Demonstration for Ireland – 2001
sankey-diagrams.com
– Blog discussing the usage of Sankey diagrams
IEA Energy Balance Flows
– Containing International Energy Agency's data on over 150 countries and regions

– Interactive visualisation tool for the annual energy balance data of 42 countries reporting to

Grassmann diagrams
(

exergy In thermodynamics, the exergy of a system is the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir, reaching maximum entropy. When the surroundings are the reservoir, exergy is the pot ...

flow, destruction, and loss) {{DEFAULTSORT:Sankey Diagram Diagrams Irish inventions British inventions Things named after people

History

Science

Active examples

See also

References

External links