A national map of cycling to work

I've recently being doing some visualisation work with the newly released Census commuting data from 2011. I've produced maps of all travel to work, and travel by car, train and bus. I've now done a map of cycling to work (below). This map is particularly interesting in relation to the patterns it reveals but also in relation to the strange long-distance flows we can see. I'm certainly not saying that anyone actually commutes by bike between Manchester and Bristol, as the map may suggest. Click on the big version and have a look around to see if you can spot anything interesting or particularly unexpected. A version with some place name labels can be found here.

Go to the full size version

This data comes from Question 41 of the 2011 Census form, which asked people to say how they 'usually' travelled to work in relation to the mode of transport which accounted for the largest part, by distance, of their journey. The results can look quite beautiful on a map, but they can also be confusing. Look closely at the map above and you'll ask yourself why there are so many long distance cyclists in England and Wales. More seriously, you might begin to question the validity of the data, the honesty of respondents or some other aspect of the results. 

The ability to interrogate datasets in this way is one of the strengths of visualising large datasets in that we can often immediately identify anomalous patterns or results that confound expectations or are just plain wrong. I'm not entirely sure what's going on with the long-distance flows. Perhaps some people take their bike on a train so ticked the 'bike' option, despite the train journey being longer. Perhaps some people live in one part of the country during the week and cycle to work there but then live at their usual address during the weekend and this is registered as their residence on the Census forms. I'm only speculating but this could be one possible explanation. 

In the image below, I've filtered the data so that only flows of 2 or more are shown. This significantly reduces the visual clutter, but also draws out stronger long distance connections between places such as Bristol and Manchester, and indeed Manchester and lots of other places. Take a closer look by clicking the link below this map. I've added some place names to this map to help with orientation.

Go to the full size version

I'd be keen to hear different interpretations on the data. You get similar results when you map the 'walk to work' data so there's definitely something interesting going on with how people have answered the Census question and the data we have to work with. I'm certainly not saying it's 'wrong', more that we need to understand what exactly it tells us. For now, I'll leave it at that.

N.B. Why didn't I include Scotland and Northern Ireland? The data are not out yet. It's not some ploy to exclude anyone and I know the blog title says 'national' so forgive me if that threw you. I intend to expand the analysis in due course.

Population 'explosion' in English city centres

A paper I wrote about English urban policy and the 'return' to the city is now out in Cities, so I thought I'd blog about it. It's just something I wrote after the first release of small area data from the 2011 Census and the results are not entirely surprising to those with a knowledge of these things but the scale of change over the decade from 2001 to 2011 was pretty big, particularly in the case of Manchester, which I've written about previously. I also reflect upon wider international issues associated with 'reurbanization' (with a z because it's a US journal!) so I think that although the focus is on England it should have wider resonance.

I discuss this growth in the context of New Labour's urban policies, and particularly those which emerged from the Urban White Paper of 2000. Although some of the aims were achieved (e.g. making city centres look nicer, with better design), I conclude that the changes have been mostly superficial and that perpetually high levels of inner city deprivation in cities which were the main foci for urban policy during this period does not represent a very positive legacy, despite the 'success' of getting people to move back to the city. The fact that this picked up immediately by @urbandata suggests that these themes are also relevant in the United States, and beyond. It's a short paper but I hope to follow up on it at some point* with more detailed data on tenure, etc. to dig a little deeper.

*This is normally code for 'it will never happen'!

Toddlers, teens and yoofs - where are they?

I've been doing some work on child poverty and social mobility recently, and part of this has involved looking at simple stats like the percentage of people in each area who are under 18. This has given me a better insight into which areas might be most affected by children's issues and policies. I've been looking across Great Britain but focusing on England and Wales and so I thought I'd just post a couple of maps showing the % of children across London Boroughs and the core cities - see below.

Bigger version for London

The results are quite striking - and particularly interesting I think are the differences between and within the core cities. What is also very interesting is the spatial divides in terms of which areas have a high concentration of children and which don't. These data overlap with many other datasets - which is partly what I'm looking at in my research right now - but this post is simply about the two maps.

Bigger version for core cities

One academic-related thought on this, though. I've been looking at the literature on neighbourhood effects over the past few years and following with interest the debate on where people 'choose' to live. This got me thinking about who might not get to choose, and children is one obvious group. As you can see from the maps there are large areas where 25% or more of the residents are children, and some areas where it is nearly 50%. Also interesting for me is the extent to which city centres in (e.g.) Liverpool, Birmingham, Manchester and Leeds are largely child-free - possibly linked to the concentration of students and new city centre living. Anyway, that's enough for now.

Technical note: this is done at the lower super output area level and for the local authority boundaries of the English core cities, plus all of Greater London. The data are from 2011 Census table KS102EW.

The Highlands and London: lots of space vs. lots of people

I've been doing some work recently looking at local authority data from across the UK. One thing that always fascinates me about this is the differences between areas at a very basic level, such as the different sizes and populations of local authority and other sub-national areas. The two examples which always stand out in my mind are the Highland council area (because that's where I'm from) and Greater London (because it's so big and dynamic). The other reason the Highland council area stands out is because it is by far the biggest local authority in the UK. It's bigger than both Wales and Northern Ireland, yet it only has 232,000 people. London, on the other hand, would fit into the Highland council area about 20 times over yet it has 8.2 million people - as you can see from the map (click to enlarge - and see full screen here).

The map above shows Greater London and the Highland Council area mapped to the same scale, with London moved to the middle of the Highlands (not expecting this to become official Scottish Government policy any time soon, but you never know). Greater London is about 40 miles across but it is totally dwarfed by the Highlands. What is the relevance of all this? Well, it is interesting to think about this in the context of local government and the challenges they currently face.

Within Greater London you have 32 Boroughs plus the City of London all performing a variety of functions and in the whole of Scotland there are 32 Council Areas (which esteemed blogger Peter Matthews can list alphabetically off the top of his head). In the context of the ongoing fiscal crisis, there has been some talk of merging all local authorities in Scotland. I doubt it is going to happen but you never know. A Scotland on Sunday article on it from late 2012 seems to suggest there is some truth to the idea.

Population growth in Manchester city centre, 2001 to 2011

Manchester city centre experienced a population explosion between 2001 and 2011. In the area covered by the map below the population increased by nearly 400% - from 5,957 to 23,295; a rise of 17,388 people.  In 1991, the same area (roughly) had a population of 2,887, as you can see here. Anyone who knows Manchester will know about this but possibly not about the scale of the change. A lot has been written about these changes (e.g. Centre for Cities in 2006, Manchester Evening News in 2012) but it is clear that much of the growth experienced in Manchester has been driven by a new phase of city centre living. Click an area on the map to find out more about it and zoom in to the larger version of the Google map to see it in more detail.

Click for larger version of this map

But who are these new residents? Chris Allen, writing in 2006, said they might be a mix of 'counter-culturalists' from the new middle class, 'city centre tourists' from the service class and 'successful agers', who tend to be over 50. Whoever they are, they're living in the new apartment buildings that began to sprout in the perforated urban landscape of central Manchester over a decade ago.

The map above contains a total of 15 small areas known as super output areas. If you click on any area you can find out how many people now live in each. The map also tells you the total land area of each small parcel and how many households are in it. You can find more of this kind of information via the Guardian datablog and also by clicking through to the raw data on the ONS web pages. It was only released on Friday but I've been looking at it now because I'm writing a short paper on small area population change in the English core cities. Central Manchester has grown the most but other cities have also experienced rapid expansions.

A note for spatial analysts: the 15 LSOAs you see in the map above are new. They are just 15 of the 229 new LSOAs across the core cities and this makes change over time analysis a little more tricky. Manchester's total population growth during this period was just under 20% (or 80,000) so the growth in the centre accounted for just over 21% of the increase.

Small Area Population Change in London, 2001 to 2010

Every ten years, data nerds in the UK get very excited by the prospect of getting their hands on new Census outputs. If you're lucky enough to be Canadian then you can get excited every five years but for many of us (Americans and Chinese included) it's the decennial Census that really does the trick. In the UK we can expect the first results in July 2012 according to this document. But what about in between Census dates? This is where small area data analysis becomes tricky. That's why the ONS publish mid-year population estimates for small areas in England and Wales. 

I've been looking at data for London again, so I thought it would be interesting to see which small areas have increased in population and which have declined in the period from 2001 to 2010 (the most recent data). Some map results below, but it is interesting that 11 areas (LSOAs) have more than doubled in population during this time. 

See this map with Borough outlines on a separate web page

• The 11 areas which have more than doubled in population are in Tower Hamlets (4), Greenwich (4), Ealing, Enfield and Hounslow
• 85 areas have increased in population by 50% or more between 2001 and 2010
• 344 areas have increased in population by 25% or more between 2001 and 2010

• 5 areas have decreased in population by 50% or more - these areas are in Greenwich (2), Southwark, Brent and Newham
• 19 areas have decreased in population by 25% or more during the 2001 to 2010 period.

Overall, the population of London has increased by hundreds of thousands between 2001 and 2010. According to the mid-year population estimates it has increased by approximately one Manchester in population terms (i.e. about 500,000 - equivalent to the City of Manchester population in 2011). That's about a 7% increase. 

The data are somewhat experimental but if we aggregate up to Borough level, then Brent and Newham both show losses (about 5% and 4% respectively) whilst City of London (60%) and Westminster (25%) show the largest gains.

This data for London - and lots more - can be found on the pages of the excellent London Datastore.

Daytime Population in the United States

My last post on London's Daytime Population is getting a lot of page views, which is nice, so I thought I'd do something else on the same topic. Although I do try to make nice images with data, there are some very important planning-related issues here. The first is just to do with the importance of knowing how many people live in an area. In New York City, the city challenged the 2010 results because it could have led to less federal aid, and in the UK in 2011 the city of Cardiff claims there was an undercount which could have led to them missing out on £85 million of funding since 2001. In relation to daytime population, this is also very important, but more difficult to calculate, as Robert C. Schmitt discussed in 1956. So, I looked at the 3,111 counties of the lower 48 states in the US and mapped them by daytime population density, as you can see below.

View full size version

Why does it matter that we know what the daytime population of a place is? Well, there are many reasons including planning for public transit, traffic flow, infrastructure needs, utilities and even for developing evacuation procedures (Schmitt was writing in 1956 but perhaps this last point is still relevant today).

In the United States, the county with the highest daytime population density is New York County (aka Manhattan). It is far and away the leader in this category, with 126,100 persons per square mile. That doesn't quite match the daytime population density of the City of London but bear in mind that Manhattan covers 22 square miles! Manhattan's daytime population is also about 1.3 million more than its total resident population, which in 2010 was about 1.6 million.

Comparing Populations: China, US, Europe

Since the US and China have both recently (2010) conducted a census I thought it would be interesting to look at some of the population results. Given the vastness of the US and China, I thought I'd do a little experiment and compare Chinese province populations with US states and European countries. I've put this data into a spreadsheet as well and also produced a map graphic comparing various areas. The purpose here is to highlight the large populations of so many Chinese provinces.

Some interesting nuggets from the data...

• Guangdong province in China now has a population of 104 million, which is more than any European nation except Russia (141 million). The European part of Russia has 110 million. 
• Poland, Shanxi province and California all have around 37 million people. 
• Shanghai has 22 million compared to Romania at 23 million. 
• Beijing and New York state both have about 19.5 million people. 
• In total, ten Chinese provinces have a population of 50 million or more. The US and China have a very similar land area. 
• Be honest, did you know that Anhui province has about the same population as Italy (60 million)?

Finally, some non-Chinese comparisons. Greece and Ohio both have a population of about 11.5 million and Michigan and Belarus are similar at about 9.5 million. Wisconsin and Denmark both have about 5.7 million people, and Finland and Minnesota have about 5.4 million. At the lower end of the scale, North Dakota and Montenegro both have about 670,000 people.

United States Census 2010

The 2010 US Census was conducted in April 2010 and already the results are looking very interesting. By the end of 2010 there was a new total population figure for the US, indicating a growth of 9.7% between 2000 and 2010. The total population on the twenty third US Census day was 308,745,538. This is just over double the total population from 1950. For a more up to date population estimate, you can check the US population clock from the US Census Bureau. Because I'm interested in all this, I've produce a graphic which shows population density and some population data for the lower 48 states, at county level. A couple of nuggets here: Los Angeles county has nearly 10 million people and Loving County (Texas) has only 82 people. All other counties lie somewhere in between...

A Vision of Britain Through Time

I've been doing some work recently which involves the analysis of population change in England from 1801 to 2009. The data for this has come from the Census (which goes back to 1801) and mid-year population estimates (for 2009). The data itself has been sourced from a wonderful website called A vision of Britain through time, based at the University of Portsmouth. It's an innovative and pretty comprehensive exercise in historical stats and historical GIS.


As you can see from the screenshot above, you can enter a place name to find a place, you can look at various landcover maps, you can look at historical maps, Census reports and even travel writing by such distinguished contributors as Samuel Johnson, Daniel Defoe, Celia Fiennes and the wonderfully named Gerald of Wales.

Samuel Johnson's writing is from his 'A Journey to the Western Isles of Scotland' and is both shocking and funny seen from today's perspective. He very much disapproves of the 'Highland manners' and he calls Loch Ness 'a very remarkable diffusion of water without islands'.


The maps (as above) are really interesting and you can, for example, take a look at your area in the 19th and 20th centuries as well as look at the present day OpenStreetMap version.

To sum up, lots to look and and worth a look.

CommuterView, ONS, etc.

I got back to work after a week away and in my mail I discovered a new DVD from ONS. This was the CommuterView DVD I had been waiting for. What is it? It's an interactive flow mapping tool showing all commuting flows in the UK from the 2001 census, down to LSOA level. It's very interesting and is similar to the kinds of things I've previously done with migration data.

Another important development is that from April 1, 2008 the Office for National Statistics became the executive agency of the new UK Statistics Authority (UKSA). The UKSA is accountable to parliament rather than a government minister (as ONS was). The aim of this is to restore public trust in the quality and integrity of official statistics. They also have some pretty new logos.

Yesterday I received an interesting e-mail from a PhD student at MacQuarie University in Australia asking about flow mapping techniques, but they are looking at communication linkages in settlements in Bangladesh rather than migration/commuting in the UK. I'm going to try and be of help as it sounds interesting and any kind of global communication on flow mapping is surely a good thing.

What else? I've also been exploring the new tools available in Google spreadsheets and the 'heatmaps' in particular. These could be very useful tools indeed but I couldn't find a quick and easy way to resize my maps and there are still quite a few restrictions. Not a replacement for doing similar things in GIS but an interesting development. Still waiting on my new copy of Camtasia Studio 5. I'm working with 3 at the moment and plan to produce a 'how to use Camtasia' demo eventually - this will involve a screencast of screecast software. This is possible if you have two separate versions installed, just as it is possible to run Excel 2003 and 2007 on the same machine, for example.