Available for download now
The CDU's Casweb service has been enhanced to provide users with digital boundary data to accompany 2001 census data downloads in a range of standard GIS formats ready for mapping and spatial analysis. This development significantly simplifies and speeds up the process of producing maps and performing GIS-based spatial analyses using 2001 census data by removing the previous requirement to access the two kinds of data from separate sources and perform joins between them.
The Digital Boundary Data is available in ESRI Shape, Mapinfo Tab and Mid/Mif and also GML. Other formats may also be released if there is a user requirement for them.
The current release is to be considered a beta version that may undergo some changes to increase functionality, speed and stability. The CDU will cease development at the end of August and release a stable version in time for the new academic year.
The 2001 DBD in Casweb was sourced from UKBORDERS at EDINA and is stored in a SQL Server 2008 database here at the CDU. This will allow us integrate the data into future projects such as a new visualisation system and also into the InFuse Project which is designing the succesor to Casweb.
Generalisation
In order to accomodate the boundary data at Output Area level, which in its raw format for England alone is 1.3Gb, we are using a data reduction technique called generalisation (or generalization). Generalizing boundary data makes the polygons less intricate and therefore require less points to describe them. For Scotland, Wales and Northern Ireland the data is taken from a generalised boundary dataset created by UKBORDERS. For England the CDU have created one a generalised boundary data set using the same Douglas-Peucker algorithm employed by UKBORDERS at Output Area.
Special Conditions Registration
In order to use the 2001 Census Boundary Data, user will be required to sign up for three Special Conditions. Casweb will check your current level of permissions and prompt and direct to the relevant web pages for instant signup where necessary.
You should be able to use Casweb to download your 2001 Census data integrated into your favourite GIS format and have maps ready within just a few minutes.
