Author Topic: Great Britain civil parish boundaries  (Read 2452 times)

PeterC

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Great Britain civil parish boundaries
« on: 14 November 2016, 07:01:22 »
To get Great Britain civil parish (and ward etc) boundary maps for free go to https://www.ordnancesurvey.co.uk/business-and-government/products/boundary-line.html.  There you can view the description of the Boundary Line product, and then click on the link to download it.  This takes you to the order page, and you select the product using the right hand checkbox (for download rather than DVD). Click Next and fill in your details, and you will receive an email with the data files attached. Unzip them and place the resulting folder (bdline_essh_gb) where you want it.

When you have the data:
Make sure you know which civil parish(es) you are interested in, and their exact spelling. The most useful site is:Other sites that can help include:
To extract a single civil parish (CP):
  • open a new project in QGIS
  • in Project Properties/CRS, ensure that 'Enable on the fly' is ticked, and CRS 27700 (British National Grid) is selected
  • load in the (\Data\bdline_essh_gb\Data\GB\)parishregion.shp file (or for wards: district_borough_unitary_ward_region.shp)
  • right click the layer and open the attribute table
  • bottom left, under Show all features, select the Field filter and NAME field
  • enter the CP name (or enough of it) into the search box, and press Enter
  • (an alternative is to zoom the map to where you want then select the filter option to Show Features Visible on Map)
  • select (click on) the CP you want, making sure you have selected the whole row
  • click on the button to copy selected items to clipboard (or just Ctl C)
  • go the main QGIS window and then do Edit -> Paste features as, and choose New vector layer
  • select 27700 in the first dialog box
  • in the second dialog box, choose geojson, Project CRS (27700 again), and for the Save as output, browse to the OPS's folder, and give it a filename incorporating 27700 in the name, eg Dunster CP 27700
  • click on OK , and the new layer will be added
  • you can check you have the correct CP by right-clicking on the new layer and then Zoom to Layer
  • this 27700 layer is most use for clipping other data (ie restricting it to just the relevant CP)
  • right click on the resulting (27700) layer and then Save as
  • but this time choose geojson, 3857 and the output filename (incorporating 3857 in the name)
  • repeat the right click and Save as, but for 4326

You now have three versions of the same CP boundary "feature" (probably a polygon, but possibly a multi-polygon), each in a different projection. These can be useful for clipping large datasets in future, but it is the 4326 version you will want to load into M4OPS. You can now close QGIS and there is no need to save the project.

You now need to add a row into the LayerDefs_Feature.csv for your OPS. It is probably easiest to start by copying a similar line from another OPS, but the fields required in LayerDefs_Feature.csv for this include (the fields that differ between OPS are in bold):
  • layertype: Vector
  • category: Local
  • title: (eg) Dunster CP
  • csvname: (null)
  • candownload: TRUE
  • url: (eg) Dunster CP 4326.geojson
  • attribution: #OS# - the standard OS attribution
  • shorttext: NAME - this tells M4OPS that where it expects a shorttext field it can use the NAME field
  • layerdescription: #B-L# - the standard Boundary Line description

To complete the task:
  • in M4OPS for your OPS (NB Peter do DEV first!), click on Choose Files
  • using the Choose Files button, select the 4326.geojson file (technically 4326 = urn:ogc:def:crs:OGC:1.3:CRS84)
  • click on Upload, and enter your OPS password - you should get a message saying it worked OK
  • now Choose File FLG\LayerDefs_Feature.csv, and click on Upload - you should again get a message saying it worked OK
  • click on Compile, (if necessary, enter your OPS password) - you should get a message saying it worked OK, with the number of bytes saved
  • clear your browser cache, and refresh M4OPS
  • you should see the CP boundary layer as one of the feature layers (click on Go to see the whole CP)

Other UK boundary types (besides civil parishes) that are included in the download you receive, that you could extract in a similar way, are:
  • european regions
  • counties
  • districts, boroughs and unitary authorities
  • scotland and wales constituencies
  • westminster constituencies
  • greater london constituencies
  • unitary electoral divisions
  • county electoral divisions
  • wards
  • welsh community wards
  • high-water mark (these are polylines)
  • ceremonial counties
  • historic counties

If you want more than one (eg) CP boundary in the layer then you need to Select each of the others, Copy, and Paste features as, and but this time choose Current vector layer. In this case select the filter option to Show Features Visible on Map is most useful.

Licensing aspects are covered at https://www.ordnancesurvey.co.uk/business-and-government/licensing/using-creating-data-with-os-products/os-opendata.html. In summary it says:
You are able to use OS OpenData datasets in any way and for any purpose. We simply ask that you acknowledge the copyright and the source of the data by including the following attribution statement: Contains OS data © Crown copyright and database right (year).
Your use of OS OpenData products is subject to the terms of the Open Government Licence.http://www.nationalarchives.gov.uk/doc/open-government-licence/

More details of how to work with the data is at: https://www.ordnancesurvey.co.uk/business-and-government/help-and-support/products/opendata-getting-started.html
« Last Edit: 21 March 2017, 08:24:11 by PeterC »