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Methodology behind Bill Yoder’s work on the thumbnail panels at the bottom of The Population Map:

The Cartograms: Images #2-6

During the development of the continent based cartograms many skills were required, including: geography, art, and math.  These are the same basic skills that are required in the development of any cartogram such as the main image of this map.   In my case the basic population numbers were provided for the different cartograms by Fred Pearce, and Bob Abramms suggested his recommendations for the scales.  One main concern while creating the cartograms was that they needed to appear as similar as possible to each other while also resembling the overall shapes of the continents in the main image.

In order to accomplish this, the scale for each of the cartograms needed to be manipulated to achieve the similarity while also accurately representing the human population for each of the time frames.  This resulted in a multi step process where the scale and general shapes was manipulated for each of the cartograms.  During each phase of this process the cartograms were reviewed and compared by Bob Abramms and myself until the cartograms were completed.  One of the main problems encountered during this process was maintaining consistency of the overall shape and locations of the continents in the cartograms when compared to each other and the main image.

Population Density: Image #7

            The world population density map presented its own set of problems.  The first of these was gathering recent and accurate population data.  While this does not at first seem like a large problem, most population data is provided on a country basis.  This type of data will only allow for the display of human density on a country scale and does not show specifically where humans actually inhabit the land masses.  In some cases human density is placed into a grid type format, which does show the population density as it actually occurs over the surface of the planet.  Examples of such maps can be found on the Center for International Earth Science Information Network, at: http://sedac.ciesin.org/plue/gpw/index.html?main.html&2.  After analyzing many such data sets it became clear that I would have to compile a data set of my own that would allow me to control the scale of the areas represented while also providing a consistent number of humans for a given area.  This became necessary due to the different sizes of the areas involved and the number of humans for each of these, providing many different density numbers over the surface of the globe.  A benefit of going through this lengthy process was that it allowed me to update population numbers around the world to more accurately reflect current populations.  Once this data was accumulated and a density map was completed it was just necessary to clean up the initial map so that it could easily be displayed and printed at the smaller scale required for this publication.  This was an iterative process involving Bob Abramms and myself, to complete the final map.

                                                                        Bill Yoder