Articles

Not so fast…

In maps, redistricting on September 30, 2011 by dadge

Coming back to the subject of mapping, the Guide to the Review (pdf) (paragraph 16) states:

The local government boundaries that the BCE is using for the 2013 Review can be found in the Ordnance Survey’s Boundary Line mapping product (October 2010 version). (Available free of charge at 1:50,000 and 1:250,000 scale* from customerservices@ordnancesurvey.co.uk or 08456 050505.)

This sounds all fine and dandy, so what happens when you contact the Ordnance Survey? You get this reply:

Thank you for your e-mail.

The product Boundary Line is available through the OS OpenData initiative. OS OpenData is the launch of a specific suite of datasets as part of the drive to increase innovation and support the Government’s ‘Making Public Data Public’ initiative. These datasets can be accessed at no cost and exploited via a very simple set of licensing terms. A new online service allows users to view, develop, download and order the OS OpenData products.

The products through the service are updated at regular intervals. Unfortunately, we do not hold the historical data after the updates. The Boundary Line product was updated in May 2011 and thus we no longer have the 2010 data.

If you have any further enquiries please let us know. (Emphasis mine.)

Hm. I emailed the Boundary Commission about this problem on Monday and I’m still waiting for a reply.

***

Meanwhile, I went to the OS website and got hold of their chunky “Boundary Line mapping product”. *No mention of scale – this is either something the Commission has made up or not explained properly.

When you download Boundary Line you might be forgiven for thinking you’re downloading a set of maps, but no, it’s a set of data. So, what am I supposed to do with it? The answer I found, after a bit of digging on the OS website, is “open your GIS”. I know this may be hard to believe, but I’ve never owned a GIS, so I had a hunt around for one. The best one appears to be ArcGIS, but I discovered after I’d downloaded it that my system can’t run it. So I asked the great guys on the Vote UK forum for advice, and they recommended Quantum GIS. Bingo! Er, not so fast.

***

Next problem: how to load the OS data into the GIS. A quick look at the manual and a bit of trial and error and I used the “Add Vector Layer” icon at the top to load the “shapefiles”. A bit of playing around and I’ve come up with a pleasing result:

Do you notice something? If you’ve been following the story closely, you’ll remember that this is the 2011 version of Boundary Line, so in places like Cheshire where the boundaries changed this year, the boundaries don’t match the ones the Commission has used.

But why, I hear you ask, are they using old boundaries anyway? Well, the legal position is (contd p.94)

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