A Population Cartogram of New Zealand

Which depiction of New Zealand (below) is more representative or accurate?

From a navigational or geographical perspective, the image on the left is more accurate. But what if you wanted you wanted to look at the country from another angle, such as population?

If you wanted to get more information on the population distribution of the country in more detail, a traditional map would not be very useful, unless you knew the population was distributed perfectly evenly everywhere.

Obviously, New Zealand’s population is not distributed evenly. Urban regions will contain more people in a given area, and rural areas will contain fewer people.

How do you visualise this though?

In this article, I have attempted to this. By collecting land area and population data for each of New Zealand’s 16 regions, I have constructed a cartogram (above, right) which re-sizes each region based on their population. This can be compared with an ordinary map of New Zealand.

While this cartogram and the traditional map of New Zealand are curious to look at and compare, ordinary bar charts of the information itself can also add perspective.

These charts show that while Auckland is the second-smallest region in the country in terms of area, it is by far the most populous. In fact, Auckland has nearly three times the population of Canterbury, the second-most populous region in the country.

Wellington, with around 8100 square kilometers, is the fourth smallest region but the third most populous.

The West Coast region is fifth largest, but has the lowest population out of all 16 regions, and contains only 1/47^th of Auckland’s population.

Waikato has nearly an equal share of New Zealand’s population (9.6%) and land area (9.4%)

Land area and population data can be combined to calculate population density, which in this article is measured in terms of ‘people per square kilometer’.

Auckland, at 312 people per square kilometre is the most densely populated region in the country, and is over 200 times more densely populated than the West Coast.

Nelson is an especially unique case. It is the smallest region and at less than one-tenth the size of Auckland (the second smallest region), it stands as an outlier in these charts. The Nelson region also has the second-highest population density.

An expanded cartogram of New Zealand by regional population is below. 

Some obvious points of interest are the increased size of Auckland and the North Island compared to the rest of the country and the South Island, but other noteworthy elements include:

• The dramatic decrease in size for the Tasman, Marlborough, Southland, Otago, West Coast and Gisborne regions. The re-sized versions of the West Coast and Gisborne regions seem particulary miniscule compared to their true areas.

• The slight decrease in size for the Manawatu-Whanganui and Hawke’s Bay regions.

• Northland, Waikato, Bay of Plenty, Taranaki, and Canterbury remaining roughly the same size.

• Wellington increasing significantly in size.

In the past, the South island regions had a larger share of the country’s total population than they do now.  It would be interesting to have a series of cartograms based on historical population estimates to see how the location of New Zealand’s population has changed in the past, and how it might change in the future.

Sources

Subnational Population Estimates: At 30 June 2014 (provisional). Retrieved from http://www.stats.govt.nz/browse_for_stats/population/estimates_and_projections/SubnationalPopulationEstimates_HOTPAt30Jun14.aspx

Land area data: retrieved from regional council websites