Another day, another visualisation from our new favourite geographer, Alasdair Rae.
Last week we ran some fascinating maps he created showing the population density (and, consequently, urban area) of major British cities. Now, he's created a visualisation that shows the limits of this type of static density modelling: an animation that shows the massive population shift that takes place every day as workers commute into the City of London.
The visualisation is based on 2011 census data showing daily commuter journeys into the square mile, London's main financial distract. It shows commuters speeding into the city's centre from as far away as Bournemouth and Margate. It's also completely hypnotic to watch:
Each of those dots represents at least 25 commuters, and as the colours get lighter, the density gets higher. If you look closely, you'll see that the City of London itself starts with incredibly low density in the mornings, and then becomes white hot with people by the time the working day begins.
The dark green area, meanwhile, is green belt. The visualisation shows quite how many people have to cross it from the communities outside it to get to their places of work.
The animation reminds us a bit of these maps, showing day and nighttime population density in Manhattan:
Image: Joe Lertola, via Time Magazine.
This type of time-sensitive modelling gives us a better insight into how cities are actually used. As Rae's animation demonstrates, questions regarding the housing and transport needed to supply London with workers isn't restricted to the city itself: you need to consider a zone stretching 60-odd miles in every direction.