Green Belt boundaries for England have been released as open data

Post: 10 October 2014

The Department for Communities and Local Government has released Green Belt boundaries for England as a polygon dataset, for re-use under an open data licence.

The dataset may be downloaded in shapefile format from the OpenDataCommunities website.

I've written previously about the arguments for open data release of this dataset, as has Alasdair Rae of the University of Sheffield.

Another version of DCLG’s Green Belt dataset has been in circulation since 2012 when it was published on the Telegraph website. However yesterday’s release is the first time DCLG has officially made a Green Belt dataset available on open data terms.*

* Update: Jeni Tennison points out that this dataset is also available via a link from a Data.gov.uk catalogue record. The link seems to have been added in May or June.

The national Green Belt dataset is compiled from spatial data provided to DCLG by local planning authorities. (Earlier this week DCLG published new planning guidance on green belt boundaries.)

I’ve had a quick look at the data. Following are some notes:

• The data is re-usable under Ordnance Survey’s OS OpenData Licence. (The Gemini metadata refers to the Open Government Licence, but presumably that’s an error.)

• This Green Belt dataset is not the same as the version released in 2012 by the Telegraph. However, like the Telegraph version, the dataset appears to represent green belt coverage for the 2011-12 year.

• DCLG publishes annual National Statistics on green belt coverage. Statistics for the 2012-13 year were published in March 2014, so I would have thought DCLG could also release a 2012-13 version of the boundary data. One of the main purposes of the statistics is to track year-on-year changes in green belt coverage. These changes will be easier to visualise and understand if we have a time series of open data releases.*

• It is difficult to reconcile the polygons in the spatial dataset closely with the hectare figures in the statistics, for some geographic areas. The spatial dataset is serviceable, and I appreciate there are variations in the quality of the underlying data provided by local planning authorities. However I think there is an argument for regularising the open spatial dataset so that it is interoperable with the National Statistics table, i.e. with one object for each local planning authority and matching hectare calculations.

Update: Alasdair Rae has produced an experimental web map using the Green Belt dataset.

* Update 16 October 2014: Statistics for 2013-14 have now also been published.

* Update 28 October 2014: The 2011-12 Green Belt shapefile now seems to have been replaced by a 2013-14 version on the OpenDataCommunities page.

Image credit: Produced from the dataset discussed above. © Department for Communities and Local Government. Contains Ordnance Survey data © Crown copyright and database right 2012.