How Many People Live in Manchester?

A quick post on a common urban theme. Answering the question of how many people live in a city is very tricky. Do you use the political boundaries of the local authority? Do you use the extent of the urban area? Do you use some other definition? In a completely unscientific experiment, I've developed a different approach - and it turns out that the populations I come up with are not that different to those given for the city-regions of the places on my list.

Here's what I did... I took the eight core cities in England, plus London and chose the main central train stations in each of them as the central location (e.g. Lime Street in Liverpool). Then I used a bit of GIS wizardry to calculate the population within a 15 mile radius of said stations (statistically significant distance determined after much spatial analysis... and a bit off the top of my head). Here's the results (using ancient 2001 Census data):

Obviously, these figures differ a lot from the local political entities with the same names (e.g. Manchester the district has about 430,000 people). Even though I've used a fairly arbitrary technique, the populations are a much better reflection of the urban population than others often cite. So, let's compare the figures. On Census day in 2001 London had 7,172,091 people, Birmingham city-region had 2,693, 917, Manchester city-region had 2,482,328 and the other cities on the list show similarities to the 15 mile figure. What does this tell us? Not much really, except that if we use a 15 mile buffer from central train stations we get a good approximation of city-region populations for the major English cities. Here's how it looked on the map:

My Rules of Screencasting

Others have written about how to do screencasts most effectively. Like I said in a previous post, much of it is very useful. I just thought I'd add my own rules that I use when creating screencasts just in case anyone is interested.

1. If it's worth screencasting it's worth sounding interested in it. Try to be enthusiastic without speaking too fast. (I may be guilty from time to time here)

2. Make sure you record the screen at sensible size. I use a window size of 800x600 and I get it to this size by using a great little app called sizer (see below).

3. Always record in Flash for movies of the highest quality and easy distribution over the web.

4. Use a good microphone - I use a Logitech USB mic and the sound is crisp and crackle-free. (My earlier efforts were not so good!)

5. Go easy on the 'special effects'! Don't use the George Mallory approach. Works great for mountains but not for screen capture software.

6. Plan but don't script. Know what you're going to do but not necessarily exactly what you are going to say. (And don't worry about little mistakes - they keep it human - if you are one)

7. Work towards a standard format that your viewers recognise and trust. I find this helps comprehension and makes learning easier.

That's all for now. There's loads of other things I could have included but they are the ones that I think are most important.

Cities are Back?

Just a quick post today regarding the issue of whether British 'cities are back'. Since the report of the Urban Task Force in 1999 and the much-cited 'urban renaissance' cities have been back on the agenda but in a more positive light than in the past. People now seem to want to live in them again, city-centre living has been given a new lease of life and huge amounts of public and private cash have been spent doing them up. However, is all of this a good thing? I would say that overall it is but I just wonder how sustainable it is. What are the implications if it all goes wrong and investors and people flood out of the cities once more? What if people don't really want to live in the shadow of tower blocks forever. What if it is not really a renaissance?

I took this picture in Glasgow in July 2004. Contrast between 1960's tower blocks at Red Road and 2000's new builds. Quite striking I think. An illustration of how urban policy plays out in reality. We'll have to wait and see how the urban renaissance pans out but for now I suppose we ought to wish it all the best and keep track of how things go.

Screencast Update

I've had a lot of positive feedback about my new screencasting project that I'm developing within Blackboard, the University of Manchester's virtual learning environment (VLE) of choice. A visitor from the US who is really involved in GIS education recently had the chance to see what I was doing and was particularly interested, and closer to home people also seem pretty enthusiastic. Obviously the VLE stuff is locked away from public view and it's not finished yet anyway, but here's an idea of how it will look to students:


In total so far I've completed about 30 screencasts but I aim to produce well over 100 for this project and now that I've got my production methods sorted out and streamlined I will start producing a lot more content over the summer. I'm going to continue to produce content that relates directly to different classes taught here at the University by me or by other teaching staff but I'm also going to do some stand-alone material that students can use as and when they want/need to. I don't like to script the screencasts because it can be a bit boring that way but I do have a plan that I stick to. There's a lot of advice out there but I think it's best to do what I know works after testing on students over a period time, although I do try to take on board what other more experienced developers have learned.

Finally, I think it's about time time that screencasting (or whatever you want to call it) should really be a lot bigger than it is. The technology is not new and everyone knows it can be done so why is it not ubiquitous? Before I sign off, I came across an interesting blog by a prolific screencaster last week - it's called Demo Girl and it's good reading.

GIS Screencasts

A quick post about my ongoing work with screencasting and geographical information system (GIS) software. Screencasts are video demonstrations of computer activity. Since teaching GIS is a very hands-on thing, screencasting is an excellent way to reinforce and enhance learning. I don't just use screencasting for GIS though; I also use it to demonstrate any kind of software or even for showing how to download material from the internet for different modules I teach at the University of Manchester. Here's a small animated gif showing the kind of thing I'm talking about:

Software like ArcGIS can be quite intimidating to new students with no experience of GIS so I find that the screencast approach is particularly effective. I'd like to think it will be much more widely used in higher education and in the teaching of GIS in particular within the next few years. The software is not difficult to learn (I use Camtasia Studio 5 but there are lots of other good tools out there - see this). That's all for now!

The Index of Multiple Deprivation 2004 to 2007

The new Indices of Deprivation for 2007 were released very late in 2007 and since this is an area I'm particularly interested in, I thought I'd blog on the differences between 2004 and 2007.

I've been exploring IMD 2007 just to see how it compares with IMD 2004 since authors say that they are comparable (but they do of course acknowledge that the methodology is not exactly the same).

For the most acutely deprived wards, there's not too much change, but the most deprived LSOA out of all 32,482 has moved from north Liverpool to south Liverpool (from just beside Anfield, Liverpool FC's stadium to Speke, by Liverpool John Lennon Airport). The list of the most deprived 100 LSOAs (about 150,000 people in total) is still dominated by the North West, with 68 out of the most deprived 100 LSOAs in England. It is also interesting to note the co-location of football stadia and the most deprived LSOAs. This phenomenon is perhaps not that surprising but it is replicated across Great Britian in other indices of deprivation. It also highlights the massive gulf between rich and poor in a very real manner.

More interesting are those LSOAs which have seen a significant change in LSOA rank. Using the 10% cut-off for change in rank (i.e. a move of 3,248 or more places up or down the list) I did a quick bit of analysis just to see how areas might have changed. In total, 2,374 of England's 32,482 LSOAs saw a change in rank of more than or equal to a 10% shift in their IMD category. That's 7.3% of all LSOAs, which seems like quite a lot. Most of these were not among England's 10% most deprived, but a handful were. Seventeen LSOAs among the most deprived 10% in 2004 experienced an improvement in their IMD ranking of 10% or more between 2004 and 2007.

Conversely, there were 11 LSOAs which declined by 10% or more between 2004 and 2007 to place among England's 10% most deprived. Most were in London. Overall, it's interesting to note the changes in ranks of areas and how extreme these can be. I just question if there can really have been that much change in 3 years in some of these cases and if so, what has caused it (gentrification? housing market pressures?). Are those LSOAs which have shown large improvements big success stories or statistical anomalies?

Lots of interesting nuggets when we compare IMD 2004 and IMD 2007.

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.