Perhaps the most defining characteristic of a city is its population. From the largest city in the world (Tokyo, population over 30 million) to the tiniest little hamlet, the population of a place obviously has a huge effect on its nature. Something I have thought about for a while is whether there might be an ideal population for a city – at what point do they become “too large” (if such a point exists)? At what point is a city stuck between being an overgrown town and something that actually resembles a bustling metropolis. Auckland seems to be borderline between the two at the moment, with the struggle for choosing which way it falls being a key issue we will have to deal with over the next few decades.
Of course, when creating an entirely fictional city, the question of what its population might be. Over the years I have struggled a bit with the scale of the maps I was drawing, some things seemed a bit too big for a certain scale, others a bit small. Eventually I settled on 1:12,500, or 1cm equally 125 metres at 100% zoom. This gives us the following approximate dimensions for the map of the city: This gives the map a total area of around 2205 square kilometres, around the urbanised area of Bangkok in Thailand and just a bit bigger than Melbourne in Australia. If the whole map was filled in, it would be around the 30th largest urbanised area in the world, by area. Of course the whole map isn’t filled in with city, with the picture below showing that fairly clearly: Now here’s where a bit of guess-work comes in to estimate the proportion of the whole map that’s actually urbanised. As a bit of a wild ‘stab in the dark’, I’m thinking around 40%. Which leaves us with an actual urbanised area of 882 square kilometres. This is similar to Madrid in Spain, or Edmonton in Canada – and still quite significantly larger than Auckland’s 544 square kilometres.
The next step in working out our population is to have a think about what the city’s average density might be, right across the urbanised area. Average density can give us some strange results, like New York being similar (and slightly below, in actual fact) the density of Los Angeles. But it’s a useful figure for this exercise. For some comparative cities to give me an area of numbers, we have Tokyo at just over 4000 people per square kilometre, Paris at 3,300, Auckland at 2,200, Vancouver at 1,700 and greater New York at 1,800. As you’ll come to learn over the next while, the city doesn’t have much of a motorway network and has a hugely developed subway and commuter rail network – so densities are likely to be pretty high to support that kind of transport system. So let’s say 3,000 per square kilometre, with a really dense central area and some lower density areas further out. Definitely the kind of overall density that would support a strong public transport system.
Add the numbers up and we get a total population of around 2.7 million. As I develop this blog and explore the city further, I will keep this figure in mind to assess whether it feels right (to be honest it feels a little on the low side). My estimate of density may change over time to reflect the kind of city I really think it is – because, as I said at the start of the post, population is that critical element.