Sunday, 18 October 2020

10x10km City Squares

Back in 2018 I created a series of images showing the urban footprints for 10x10km chunks of a variety of British cities. These square 6.21 mile chunks were related to work I was doing on urban density and I'm still looking at the topic so I'm revisiting it again and posting a new set of images here - for a selection of English and Scottish cities. This time, instead of just showing buildings, I've added in water and land because it helps with orientation and I think also looks better. So, here's the first image, a gif of English cities, at 1.5 seconds per frame, followed by the same for Scotland. Scroll to the bottom for more info on data and methods. I may turn these into prints in future as part of my Automatic Knowledge print shop, but not 100% sure yet. For now, it's just a couple of gifs and lots of images - the individual frames for each city are also down below.

40 towns and cities, 1.5 seconds each

24 towns and cities, 1.5 seconds each

How did I position these places within the 10km squares? I mostly used the default position of Ordnance Survey's populated places file (so that's the central point in nearly all squares), a complete version of which you can find on the Automatic Knowledge website. In a couple of cases I nudged things up or down a little but overall it's about 90% automated.

A major reason for doing this for multiple cities in a 10x10km way was so that I could compare them quickly, visually. A looping gif is good for that, but less good if we want an overview of everywhere at the same time. So, for that, I created a couple of tiled images - one each for England (40) and Scotland (24) as you can see below.

The 40 English cities, tiled

The 24 Scottish cities, tiled

I hope to do more on this in future, including Welsh cities. Unfortunately I cannot find open data on this for Northern Ireland, otherwise I would have attempted that as well. For now, this is just a somewhat experimental return to mapping the different urban fabric patterns of England and Scotland (and note the New Towns, like Cumbernauld or Milton Keynes). I realise that some cities that could (maybe should) have been included are left off and the choice of places will always be a bit annoying for some, so please forgive my selection process - it was driven by a mix of urban hierarchy, population, location, building patterns and personal choices.

Want the individual frames for each of the cities? Why not! See below - that's all for now, but scroll to the very bottom for more on data and methods.

Okay, so I managed to successfully upload 40 images in one go. Let's add the 24 Scottish ones now.

Data and methods: the data come from Ordnance Survey, so remember that it Contains OS data © Crown copyright and database right (2020) - but it's all open data of course. The buildings layer is from their OS OpenZoomstack product and so is the local buildings layer. I also used the surface water layer and the land layer because water is important and very relevant, but it also serves a useful purpose for orientation. To create the frames I used the QGIS Atlas tool. I then used batch conversion tools in IrfanView to resize, rename, frame and overlay text on the images. I used ImageMagick's mosaic function to tile the images together in the 4x6 and 5x8 configuration you see above. I also used ImageMagick to create the gifs. I also decided to add rounded corners this time, because I think it looks better.