This page relates to a newly-created set of 'Tracts' - these are aggregations of wards in each of the years 1981, 1991, 1998, 2000, and 2001, covering the whole of Britain. The aim is to produce a set of areas with a similar population, the borders of which remain reasonably consistent through this time period, to allow comparison of data over time. They are also designed in such a way that they can be mapped using Danny's UDM cartogram.
The following files should allow other researchers to utilise this tool. The look-up files allow you to take ward data (or any lower level that fits to ward, eg Super Output Area), for any of the years listed above, and aggregate to tracts that are comparable between different years. Look-up tables are also given for best-fit of Tracts to higher areas .The shapefiles will allow users of ESRI GIS products to map data at Tract, Parliamentary Constituency, Local Area District, and Government Office Region levels.
Look-up tables from Ward to Tract, and from Tract to higher areas (Zipped Excel file)
Traditional Map of the tracts (from 2001 wards) England and Wales (Zipped Shapefile)
UDM cartogram of the UK (Zipped Shapefile)
More detailed explanation of the creation of tracts (pdf file)
Department of Geography,
University of Sheffield, Winter Street, SHEFFIELD S10 2TN, UK
Tel: 0114 222 7900 International calls: +44 114 222 7900
Fax: 0114 279 7912 International calls: +44 114 279 7912