Cartograms are a great way of representing data that refers to people, and it allows you to give urban areas (which generally cover relative small areas) much more prominence than rural areas (which usually cover very large areas). The image below shows the usual geographic representation of the output areas, alongside the cartogram version. Note how the rural cluster (representing about 13% of the population) is very dominant in the ‘standard’ representation, but much less so in the cartogram representation.
For my presentation at GISRUK2015 on TravelOAC (travel geodemographics) I was presenting a series of cluster data by 2011 Census output areas. Output areas are based around a standard population, with the result that many rural output areas are geographically large and many urban output areas are geographically small. When considering the classification data, it makes sense to give each output area equal consideration, so I decided to create a cartogram of the output area boundaries, based on the usual resident population.
I used a piece of software called ScapeToad which is a quick and easy way to create a cartogram from a custom data set. They have a good set of instructions on their website and the processing of all OAs in England and Wales (181,408 areas, 79mb shapefile) only took 49 seconds.
I was inspired by the cartograms used on the ONS Census Interactive website showing a range of variables. There are a number of ways of generating cartograms, and the ONS team used an approach based on http://lambert.nico.free.fr/tp/biblio/Dougeniketal1985.pdf where the browser does a lot of the heavy lifting. There is also an ArcScript available for ArcGIS at http://arcscripts.esri.com/details.asp?dbid=15638 which I used a few years ago and worked well then, but I’m not sure if it still does now!
P.S. Unfortunately I didn’t manage to see Chris’s presentation on cartogram methods (http://leeds.gisruk.org/abstracts/GISRUK2015_submission_83.pdf) as it was on at the same time as I was presenting!
I presented my work on TravelOAC at GISRUK this year, based at Leeds. The conference was great and it was a great opportunity to meet an incredible range of people involved in GIS, from engineers, historians, social scientists, spatial information scientists (as they like to be called!), mathematicians and, of course, geographers. We had a great crowd on Twitter as well (#GISRUK2015) who kept everyone up to date on proceedings, and I’d particularly like to mention @adjturner who has made his conference notes available online at . I was also involved in the GIS for Transport Applications workshop, which Robin has written up. Next year, we are at Greenwich, so see you there!
My slides and paper are available, and I have also written a post about how I created the cartograms I used in my work.
View of Juniper Hall from Box Hill
Last weekend I attended the INLT Writing Retreat, at the Juniper Hall Field Centre set in “an unspoilt area of the chalk North Downs”. The INLT (International Network for Learning and Teaching in Geography) is a group of geographers who want to improve the quality and status of learning and teaching of geography in higher education internationally, and every couple of years or so, get together for a writing retreat.
I’d never been on a writing retreat before, and I really had no idea what to expect. In fact, I may not have even attended if it wasn’t for a HEA GEES workshop in Manchester on 23rd May where Helen Walkington plugged the INLT writing retreat workshop.
Once signed up, we did some work on our group topic (GIS Learning, spatial literacy and spatial citizenship) beforehand and laid out a few ideas. However it wasn’t until we were in the room together that the ideas for our JGHE paper started flowing. A mixture of writing group sessions and sessions with everyone enabled us to develop our ideas, get some very useful feedback, refine the ideas, collect some data, and do some data discussion all in a day and a half!
It was an amazing experience and I would recommend attending a writing retreat for anyone who wants to get their teeth into a discussion in their area, and get to meet some of the big names in their field.
Also posted on INLT website at: http://www.ucd.ie/t4cms/Collated%20reflections%20formatted.pdf.
Talk given at the GISRUK 2014 at the University of Glasgow 18/04/14.