Basic population counts for the census Output Areas of Great Britain in 2001, plus boundary polygons.

Table ID:

OUTPUT_AREA_2001_GB     (1252153)

Contents:

Basic population counts for the census Output Areas of Great Britain in 2001, plus boundary polygons.

Approx. number of rows:

217,881

Table type:

Raw Data

Documentation Author:

Humphrey Southall

Chronology:

The data are for the single year 2001.

Sources:

1. The boundary data were downloaded from EDINA's Easy Download facility on March 17th 2015, http://census.edina.ac.uk/easy_download.html, using the separate files 'English Output Areas 2001', 'Welsh Output Areas 2011', and 'Scottish Output areas 2001'. In each case these were the versions were non-generalised and not clipped to the coastline. All downloads were of the ESRI Shapefiles as provided by EDINA.
2. The population statistics were extracted from CASWEB (http://casweb.mimas.ac.uk/) on 17th March 2015:
   1. Selecting '2001 Aggregate Statistics Datasets (with digital boundary data)'
   2. Specifying each of England, Wales and Scotland in turn.
   3. Specifying 'OA' as the output geography.
   4. Selecting 'Key Statistics' as the dataset.
   5. Selecting 'KS001 Usual resident population' as the table.
   6. Selecting all available variables, then 'getting the data'.
   7. Selecting 'Plain text' as the output format, as the boundary data available from CASWEB were generalised.

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Notes:

1. As part of loading the boundary data into the database, we converted them from OSGB coordinates to ETRS/Lambert Conformal Conic, and assembled them into multi-polygons.
2. The Scottish version of the population data included three additional columns, 'Area (Hectares)' (see below), 'Number of Students away from home' and '2001 Density (number of people per hectare)', the last of which we did not include.
3. The boundary data for England includes two ID columns, 'label' and 'ons_label'. The latter was used to populate zone_code and link to the population statistics. The Welsh and Scottish data contained only 'label', which was similarly used.
4. Oddly, the English and Welsh boundary data both contained a 'hectares' column while the Scottish data did not, so all rows of the final table include an area_h column but its source varies.

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Checking:

1. We checked that every polygon had population data, and that every row of population data linked to a polygon, but no checking of the quantitative data was possible.

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Indices:

Index	Type	Column(s) indexed
output_area_2001_gb_pkey	Primary key	zone_code
output_area_2001_gb_idx_etrs		g_foot_etrs

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Constraints:

The table has the following associated constraints:

Constraint	Type	Details
output_area_2001_gb_pkey	Primary Key	See details above for primary key index
enforce_dims_g_foot_etrs	Check	((st_ndims(g_foot_etrs) = 2))
enforce_geotype_g_foot_etrs	Check	(((geometrytype(g_foot_etrs) = 'MULTIPOLYGON'::text) OR (g_foot_etrs IS NULL)))
enforce_srid_g_foot_etrs	Check	((st_srid(g_foot_etrs) = 3034))

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Columns within table:

Column	Type	Contents
zone_code	Text string (max.len.=14).	ONS identifier for the Output Area. This appeared in both the boundary and the polygon data, and was used to merge them into a single table.
nation	Text string (max.len.=12).	Added by us while assembling the separate downloads into a single table, and holding 'England', 'Wales' or 'Scotland' as appropriate.
pop_usu_res	Integer number.	2001 Population: All people.
males_usu_res	Integer number.	2001 Population: Males.
females_usu_res	Integer number.	2001 Population: Females.
persons_in_hhold	Integer number.	People living in households.
persons_in_inst	Integer number.	People living in communal establishments.
area_h	Floating point number.	Area (Hectares). See above for sources.
students_away	Integer number.	Number of Students away from home.
daytime_pop	Integer number.	'Daytime' population. Only in Scottish data.
g_foot_etrs	geometry	Output Area boundary, held in ETRS coordinates.