Thursday 27 October 2011

Mapping Methods

I've done a lot of mapping on this blog in recent months. Much of this has been about deprivation and my attempts to make more widely available maps on deprivation for different parts of the UK. For this, I've often used Google's Fusion Tables. The most recent work I've done with this data using Fusion Tables is to update the Welsh Deprivation work to include the most recent release of the Welsh Index of Multiple Deprivation from 2011. There's a screenshot below which links to a full page Google map. If you click on an area the pop-up will tell you all about it in relation to the WIMD data. This post isn't about the data but the most deprived area is in West Rhyl and the least deprived in Cardiff (Llandaff area).

But this post is about methods, so more on that before I go... The steps below relate to any kind of data I've mapped using Fusion Tables (warning: technical content!).

1. First of all I usually have to join attribute data to spatial data. I do this in ArcGIS but it works well in MapInfo too. If you're a MapInfo user and want to follow the steps below, use Universal Translator in MapInfo to convert the file to a Shapefile first.

2. I don't like overly detailed boundaries because of the large file sizes and often this exceeds the Fusion Tables file limit. So, I simplify the boundaries. For this, I use mapshaper, a great online tool. You can also use other GIS methods.

3. Then I use something called shpescape. This is a really great tool because it allows you just to zip your shapefile (i.e. the shp, shx, dbf and prj files) and then upload directly to Fusion Tables without having to convert to KML as an intermediate step.

4. Once there, all you need to do is go to Visualize / Map and then go to work customising things. This includes map colours and what appears in the Info Window pop up when you click an area. I've blogged on the Info Window code bit before.

5. If you want others to see it you must make it public. Just click 'Share' in the top right of the Fusion Table screen.

That's about it. The Info Window code bit takes a while to figure out but you can do so much with it.

Wednesday 19 October 2011

Deprivation in Northern Ireland

On this blog I've covered deprivation in England, deprivation in Scotland and deprivation in Wales but, to date, not deprivation in Northern Ireland. Today I'll complete the UK set by looking at deprivation in Northern Ireland according to the Multiple Deprivation Measure 2010. What I've done is produce a couple of Google fusion table maps. A screenshot from one is shown below and if you click on it you'll be taken to a web page where you can select any local authority area. Clicking an individual area on the map will reveal a pop-up with all the information for that area, including the map key...

I've also produced a full screen version of this fusion table map, as you can see below in the screenshot. Once again, you just have to click an area on the map to find out more about it.

I'm going to get on to the more general subject of mapping deprivation and different methods and options for this type of thing (including cartograms) in a subsequent post but first a quick look at the actual deprivation data for Northern Ireland. According to the MDM, the most deprived super output area is the one named 'Whiterock 2' in Belfast, though this in itself is not perhaps that significant. Of more significance is where the clusters of the most deprived areas appear - and this is generally in Belfast and Derry. These two local government areas both have 47% of their super output areas classified among the 20% most deprived in Northern Ireland. Craigavon and Lisburn are next on the list, at 27% and 17% respectively. Having said that, many of the least deprived areas are also in Belfast, but this pattern is not mirrored in Derry.

In many ways, then, spatial patterns of deprivation in Northern Ireland are similar to those in different parts of the UK, with an inner-urban focus and smaller pockets and clusters of deprivation elsewhere. These are often located in close proximity to areas of affluence, though of course that is not really what the MDM measures.

The final image is a simple dot map showing the location of the 10% most and 10% least deprived super output areas in Northern Ireland in 2010...

The last thing to say is that this measure is produced by the same team who produce the deprivation indices for other parts of the UK. The web pages for the MDM are pretty useful and contain everything you need to know.

Thursday 13 October 2011

How Big is London?

In studies of cities and urban areas, a common question that crops up is 'how big' a particular city is. I'd be inclined to answer this in terms of population, which for Greater London in mid-2010 was 7.83million. Most urban academics, however, are more pedantic and if you asked them how big London is, they might ask what you mean by 'big' and what you mean by 'London'. So, following the theme of some posts over the past year I decided to take a look at this purely in terms of the land area of some key UK 'cities'. I looked at the London Boroughs for Greater London, plus local authority areas for the English core cities, plus Edinburgh, Glasgow, Cardiff and Belfast. I then put them side by side at the same map scale and produced the following image...

The cities (i.e. the local authorities) in the image above are ranked by land area. London is the largest, at around 610 square miles, and Nottingham is the smallest at around 30 square miles. One issue when thinking about all of this is the extent to which most of the UK's cities are 'underbounded' in the sense that the core local authority area with the name of the city does not reflect the true extent of the functional urban area. Manchester is a classic example of this, whereas Leeds is more 'overbounded'. Tony Champion and Mike Coombes, among others, have written about this - e.g. in this presentation. In many ways this is quite a serious policy challenge, particularly when it comes to understanding and planning for wider metropolitan housing and labour market processes. But I'm getting carried away with myself now!

Finally, I thought it would be interesting to compare the areas in the image above to the UK's largest local authority by area. I did this because a) I'm from the Highland region and b) see reason a). The Highland region is, famously, about the size of Belgium and it is bigger than both Wales and Northern Ireland by some way. In relation to the latter, it is more than twice the size in terms of land area. However, in mid-2010 the total population of the Highland region was only 221,630. A final nugget of information: the Highland region is about 275 times larger than Liverpool. The image below shows the Highland region at the same scale as the areas in the first image. Perhaps we should all move up north and have more space! Or perhaps not.

P.S. The City of London is the smallest administrative 'district' in the UK, at around 1.1 square miles. 

Monday 3 October 2011

Comparing Populations: Night Time vs. Day Time

Esteemed Canadian and fellow researcher Brian Webb, from the University of Manchester, recently sent me an interesting image which compares the population of Washington D.C. in the day to the population at night. This got me thinking. I did a bit of digging and found some of my old data. Put simply, I had two datasets for wards in the North West of England. One file contained the resident population of wards and the other had the population of wards during the day time (i.e. residents, minus out-commuters, plus in commuters). Out of this came two visualisations, as shown below (red peaks = more people) and a short video.

I also decided to turn this into a very simple animation, which is embedded below. I have also produced a larger version of this on its own page. Note: the video embedded below will keep playing once you click play. The larger version allows you to pause the video and watch at your own pace.

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Although these are really just some pretty pictures there are some important points to be made here. We think about the population of places - and the associated local costs and constraints - in relation to resident population but in some areas the day time population is so high that the impact on the local area is far out of proportion to the size of the resident population. Another matter is the well known issue of spatial mismatch or, more generally, understanding the differences between where people live and where people work and the implications of this. 

In short, understanding the spatiality of populations is important for planning and policy purposes - these visuals are just a simple way of telling the story of data. This is important because the data on display here comes from an analysis of a commuting data matrix of 1000 x 1000, or one million cells of data. So, another point here is that data on its own is not information, as we all know.