Wednesday 3 June 2015

The beating heart of the City of London

I've had a rush of blood to the head so here I am with a second blog in two days. I'm getting some slides ready for tomorrow's Modelling World 2015 talk in London, which is all about visualising mobility (see below) so I wanted to add in a couple of new visuals on commuting in and out of London. Visualisation can often be just a lot of fancy graphics. This can be useful in itself for a number of reasons (e.g. capturing attention on an important issue, drawing attention to unusual patterns in a dataset) but since I've been working with commuting data in England and Wales I wanted to focus on flows into and out of the City of London. 

This interests me for a number of reasons, including i) commuting can play a significant role in wealth creation and it also needs to be understood in relation to how we measure GVA; ii) commuting is often very stressful and damaging to the individual - particularly long commutes - so I'm interested in the kinds of distances involved and this can be seen easily on a map; iii) commuting can often be environmentally damaging - though this isn't what I'm mapping here; iv) commuting in and around London is often about green belt hopping so I was curious to see how much commuting comes from beyond the metropolitan green belt; and v) commuting is a two-way process and affects places at both ends and in between due to travel. 

So, here's what I did. I took the MSOA-level commuting data for England and Wales (table WUEW01 here), used a bit of QGIS, extracted frames from QGIS using the MMQGIS plugin, then patched it all together in GIMP to create an animated gif. One for inflows, one for outflows and one for in and outflows (thanks to Ebru Sener for the idea). It might run a little slowly in the blog post in a browser but see below for the images. Just to clarify, I've only shown flows of 25 or more into the City of London. Those not familiar with the data should be aware the the 'City of London' refers to the small area in the centre of London and not the entirity of Greater London! An obvious point but one worth repeating in case anyone is confused. A Greater London map would have many more data points, covering most of England.

Commuting flows (>=25) into the City of London

Same as above, but going back the way

The 'pulse' of the City of London

You should be able to get a better view of the images by clicking on them individually and if you want them to work more quickly try saving them to your own machine.