Month: June 2008

History of Parties and Armies

A company named HistoryShots offers some fine diagrams, that show the development of political parties in the U.S. and two historical graphs of the civil war (1861 to 1865) that remind of Sankey diagrams. Prints of these maps can be purchased from their site.

The ‘History of the Confederate Army’ and ‘The History of the Union Army’ how armies were formed, regrouped or significantly lost men in battles. The width of the ‘arrow’ with an implicit direction along the time line (shown at the bottom of the chart) represents the number of men. Additionally, the diagram is split into three main geographical areas (Western Theater, Eastern Theater and Trans Missisipi Theater).

History of the Union Army (by HistoryShots)

These diagrams are inspired by the famous Minard chart, which shows the loss of men on Napoleon’s march to Moscow and during the retreat.

The other two graphs are in the ‘Political’ section of the HistoryShots webpage, and show the development of political parties in the U.S. from 1730 to 1892 and from 1892 to 2005 respectively. On these graphs the widths of the “bands” don’t represent votes or seats. The popularity of each party is shown as the amplitude on the unlabeled x-axis.

History of Political Parties (by HistoryShots)

Democrats and Republicans are like sinus and cosinus waves over time, a picture that continues on the 1892 to 2005 map. Or one might also be reminded of the intertwined DNA double helix structure…

Note: I presented a similar diagram for the development of political parties in Slovakia 1990 to 2008 here on the blog before.

Energy Flow in Norway Municipality

ENOVA is a public enterprise owned by the Royal Norwegian Ministry of Petroleum and Energy. It advises the ministry in questions relating to energy efficiency and new renewable energy.

One of their services is the practical development of energy and climate plans (Kommunal energi- og klimaplanlegging) for Norwegian municipalities. On their website they present a sample Sankey diagram to visualize energy flows.

The Sankey diagram shows the energy flows in the Stor-Elvdal municipality in GWh (probably per year, a year is not given). This is very interesting, as the municipality can cover almost all of its energy for industry and private households from renewable energy sources, such as biomass and wind. Energy from fossil sources is consumed through almost entirely transportation. Stor-Elvdal produces 47.5 GWh within the municipality, and imports another 35,8 GWh from wind from outside the municipality.

A small typo can be found in label on the the orange flow (saying 85,8 where it should read 95,8), but this doesn’t spoil the overall quality of this diagram painted with SDraw, I guess.

Download the publication (in Norwegian) as PDF file

Odum’s Energy and Matter Flows in Ecosystems

A visitor to this blog pointed me to the work and life of system ecologist Howard T. Odum.

Odum “in his early work used a diagramming methodology very similar to the Sankey diagrams used in chemical process engineering. In this model energy and matter flows through an ecosystem”.

In Odum’s ‘Silver Spring Study’, he

…mapped in detail all the flow routes to and from the stream. He measured the energy input of sun and rain, and of all organic matter – even those of the bread the tourists threw to ducks and fish – and then measured that gradually left the spring. In this way he was able to establish the stream’s energy budget. (Wikipedia)

This diagram shows the energy flows in the ecosystem. The main contributors are sunlight and other biomass imports. Energy “leaves” the system as exports (extraction of animals and biomass) and mainly as decomposed matter. There are no absolute figures in this diagram, but the proportions seem to be represented by the arrow magnitudes.

The diagram has a nice “natural touch” to it, and at first sight one might think that you are looking at the arms of a river delta…