The Urban Fabric of Los Angeles

I've recently become a bit obsessed with looking at the urban fabric of different cities. I've looked at building footprints in English Cities, Scottish Cities, and collected data on a number of US cities, including San Francisco, New York, Chicago and Los Angeles. I've blogged and tweeted about this quite a bit over the past few months and the reason I'm so fascinated by it is that it provides some really interesting visual insights into the spatial structure of cities. I also find it fascinating to make visual comparisons between cities, as in my 'Urban Fabric of English Cities' blog post from October 2014. Now I'm going to look at Los Angeles. I've only been there once but I found it fascinating in so many ways (urban structure; fragmented political, social, racial geography; freeways; congestion; In-N-Out Burger...). Famously, Los Angeles is also the most populous of the 3,144 counties of the United States with a population of just over 10 million. The first image below shows all 3,000,000 or so buildings in LA county - all 4,000 square miles of it (for comparison, London is 607 square miles).

Los Angeles County - population 10 million (higher res)

Anyone who knows anything about American cities will understand that the concept of a 'city' and a 'boundary' is not necessarily as straightforward as it might appear - well, at least not to me as a British person. The City of Los Angeles is a rather odd shape and has a population of about 3.8 million. The image below shows the urban fabric (building footprints) for the City of Los Angeles.

The City of Los Angeles - population 3.8 million (full resolution)

Finally, I've produced a map showing the wider Los Angeles metro area (within Los Angeles County), with the urban footprint of the City of Los Angeles highlighted. The wider metro area extends beyond the boundary of Los Angeles County and has about 13 million people. What's the point of all this? Partly a mapping experiment and partly to illustrate the idiosyncrasies of political and administrative boundaries in urban areas compared to the underlying urban fabric. This is very acutely demonstrated in the case of Los Angeles.

The City of Los Angeles in context (higher res)

If you like these images and want them in higher resolution versions just get in touch via twitter - @undertheraedar or e-mail. I've linked to a high res version for the LA city map.

Data source: Los Angeles County - Countywide Building Outlines

Manchester: a "Northern Powerhouse"

The announcement yesterday from the Chancellor that we need a "Northern Powerhouse" in England was greeted with much enthusiasm - and also a good bit of cynicism, given that it's not far from the General Election. After the announcement, the BBC asked whether more English cities should be like Manchester. What I wanted to know was how this nascent northern powerhouse compared to the already established southern one (London, I think). We all know the numbers - well most do - but what about spatial scale, density and visual comparisons? Given a previous bit of mapping on the urban fabric of England and the fact that I've been thinking about the 'underbounded' nature of the City of Manchester (as opposed to the city region), I thought I'd go a bit further with this post.

The first image here shows how Greater London compares to Greater Manchester - they're mapped at the same scale - and I've also put the Greater Manchester boundary over Greater Manchester and vice versa, just to show that they're not that radically different in size.

Greater Manchester - a large urban area (higher res version)

I've also produced the same image without the respective boundaries overlaid on each city, just to provide a quick visual comparison at the same scale.

Click for higher resolution image

Finally, in order to demonstrate the way in which the City of Manchester is really 'underbounded' in relation to its wider city region, I've shown just the urban fabric of the City of Manchester (i.e. building footprints) in relation to the ten local authority areas of Greater Manchester, beside Greater Manchester as a whole. 

Click for bigger version

I have some even higher resolution images if anyone is interested - if so, feel free to get in touch via e-mail or twitter (@undertheraedar). I just wanted to produce these images to illustrate the fact that Greater Manchester is actually very big (about 80% of the size of Greater London in area) though of course has far fewer people (about 33% of the population). It does seem like the most likely 'northern powerhouse' in England and it will be very interesting to see how things pan out over the coming years.

The Urban Fabric of English Cities

[now updated, thanks to @udlondon - scroll to bottom of page]
Inspired by some mapping in the US by Seth Kadish, the availability of new GIS open data, and the fact that I love looking at patterns of urban form, structure and density, I have created a comparative graphic showing the building footprints of nine English cities, with London at the centre (just because it's biggest). I have done this in a very simple way, with all cities mapped at a scale of 1:125,000 in the full size versions (which are massive), plus one small scale bar and a little explanatory text. Here's what it looks like:

The urban fabric of English cities (black/red, medium res)

This graphic does a good job - in my view - of demonstrating the compactness or otherwise of the cities in question. It also illustrates how tightly-bounded some places are and how under-bounded others are. For example, Liverpool is very dense and compact in contrast to Leeds but this really is a boundary effect because the size of the local authorities differs so much. The urban area of 'Liverpool' extends far beyond the boundaries of the local authority area, which is what I show above. I wanted to compare the local authority areas rather than the wider city-region because I wanted to highlight this boundedness issue and compare like with like in terms of formal administrative areas. London is obviously a bit different so I've shown the 33 constituent parts of Greater London.

Take a closer look at the graphic by clicking on the two larger images below - one in white and one in black. They are both just a bit bigger than A0 paper size in their full size versions in the zipped folder below so if you want to take a really close look, download them. I've also uploaded smaller-sized versions in the same folder. I deliberately didn't include more information on the graphic itself, but at the bottom of the post you'll see the population of each city in 2011 (which relates to the individual city images), plus its urban area and metropolitan area population. The population of Greater London in 2011 was 8.2 million (compared to 4.4 million for the other cities shown). The cities I selected are the English members of the Core Cities group, which now also includes Glasgow and Cardiff.

Click here for a full screen white version

Click here for a full screen black version

Download a zipped folder with black and white versions in different sizes.

Update: the @udlondon people got in touch via twitter to show their attempt at fitting the core cities inside the London boundary - as below - so this inspired me to try the same with the original data. The first image below is the original @udlondon artwork and the next one is my attempt using GIS. Finally, as a reminder that nothing is ever really new, I have added a similar map which we found as part of the JR James urban image archive which we launched last year. This version has 13 different cities.

A manual approach to GIS!

My attempt at the same thing, using QGIS - full size

Some of the boundaries were a bit different in those days

City	Population	Urban area	Metropolitan area
Birmingham	1,085,400	2,440,986	3,683,000
Bristol	428,200	587,400	1,041,000
Leeds	751,500	1,499,465	2,302,000
Liverpool	466,400	816,216	2,241,000
Manchester	503,100	2,240,230	2,556,000
Newcastle	280,200	879,996	1,599,000
Nottingham	305,700	666,358	1,543,000
Sheffield	552,700	640,720	1,569,000

Totals: the population of the 8 city local authority areas is 4.4 million, for their urban areas it is 9.8 million and for their metropolitan areas it is 16.5 million. I may compare metropolitan areas next time, but mapping this is a little more time consuming.