London Population Change 2001 to 2009

In a previous post I talked about the Index of Multiple Deprivation (IMD) in London, and how a “standard” representation only reflects the geographical reality of the land. By utilising a cartogram tool this potential issue can be overcome by rescaling each areal unit by its resident population, for the IMD I used mid-year population estimates available from the Office for National Statistics at Lower Layer Super Output Area (LSOA) level.

To add a layer of context to the previous maps, I have constructed cartograms for London to illustrate the change in population between 2001 and 2009. I have used 2001 census data along with 2009 mid-year population estimates to calculate the percentage change for each of the 24,140 output areas (that contain on average 250 individuals nationally) that make up Greater London for the age ranges: 0-4, 5-14, 15-24, 25-44, 45-64 and 65 and over. To create the cartogram aspect of the maps I have used the total population of that particular age range in 2009 to rescale each areal unit. I have also produced the same population change maps using the “standard” representation of London to allow comparison with the cartograms. The results of this can be seen with the “scrubber” images below.

Move your mouse over the picture, to swipe between the standard and cartogram maps showing population change for 0 to 4 year olds.
Show dividing line?

Move your mouse over the picture, to swipe between the standard and cartogram maps showing population change for 5 to 14 year olds.
Show dividing line?

Move your mouse over the picture, to swipe between the standard and cartogram maps showing population change for 15 to 24 year olds.
Show dividing line?

Move your mouse over the picture, to swipe between the standard and cartogram maps showing population change for 25 to 44 year olds.
Show dividing line?

Move your mouse over the picture, to swipe between the standard and cartogram maps showing population change for 45 to 64 year olds.
Show dividing line?

Move your mouse over the picture, to swipe between the standard and cartogram maps showing population change for 65 year olds and over.
Show dividing line?

Move your mouse over the picture, to swipe between the standard and cartogram maps showing population change for all age ranges.
Show dividing line?

While these maps are not perfect, they do give a good generalised view of how the population has changed across London over the best part of the last decade. The bulging areas of the cartograms indicate where the capital is more densely populated, while the areas that appear to have contracted are where the population is smaller. Distinct differences for how the population has changed for each age group can be seen. Children and young teenagers have experienced some of the sharpest declines in population, while the 45-64 age range shows the greatest population increase. All these maps should be viewed in the context that the population did grow in London from 7,171,942 in 2001 to 7,753,555 in 2009, an increase of 8.11%.

 


2 comments for “London Population Change 2001 to 2009

  1. Carrie Dolan
    March 27, 2012 at 7:31 pm

    These cartograms are great visual representation of population change. I’m going to use them as a reference in my UG GIS course. Previously I used the cartogram tool to look at funding distributions, but I can’t get the script to work in ArcGIS 10. Did you have to alter it for it to run or are you using an older version of software for the cartograms?

    • Chris Gale
      April 16, 2012 at 10:06 am

      I used the Cartogram Geoprocessing Toolbox (http://arcscripts.esri.com/details.asp?dbid=15638) with ArcGIS 10 and had no problems getting these, or any of the other cartograms I have also made with it, to work. It does kick up a few warning messages, but these are because some of the areal units are smaller than the smallest analysis mesh you can use.

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