Identification

Title

Data Zone Centroids 2001

Alternative title(s)

Abstract

Data zone centroids are point features that represent the population weighted centre of data zones - the core geography used for the dissemination of results from Scottish Neighbourhood Statistics (SNS). Centroids were calculated from a population weighted sum of Census Output Area centroids that fall within a data zone. Eastings and northings for each Output Area were multiplied by their population, summed based upon the data zone in which they fell, and then divided by the total population of the data zone. These centroids are in turn used to link data zones to other (higher) geographies via a spatial join, producing a 'best-fit' match between data zones and other SNS geographies. This is Version 2 of the dataset, as the original version was shown to produce bias to the north and east. There are 6,505 data zones across Scotland, and each have been assigned an individual code that follows the Scottish Government's standard naming and coding convention. The code prefix is S01, which has been assigned to designate data zones. In some cases, data zones have also been assigned a name. To date, Local Authorities that have named their data zones include Eilean Siar (Western Isles), Falkirk, Fife, Highland, Moray, Shetland, South Lanarkshire, Stirling and West Lothian.

Resource type

dataset

Resource locator

https://maps.gov.scot/server/services/ScotGov/StatisticalUnits/MapServer/WMSServer?

protocol: OGC:WMS

name: DataZoneCent2001

description: OGC View Service

function: information

https://maps.gov.scot/server/services/ScotGov/StatisticalUnits/MapServer/WFSServer?

protocol: OGC:WFS

name: SU:DataZoneCent2001

description: OGC Feature Download Service

function: download

https://maps.gov.scot/server/rest/services/ScotGov/StatisticalUnits/MapServer/3

protocol: WWW:LINK-1.0-http--link

name: Data Zone Centroids 2001

description: ESRI REST

function: download

https://maps.gov.scot/ATOM/shapefiles/SG_DataZoneCent_2001.zip

protocol: WWW:DOWNLOAD-1.0-http--download

name: Data Zone Centroids 2001

description: ESRI Shapefile Download

function: download

Unique resource identifier

code

SG_DataZone_Cent_2001

codeSpace

www.gov.scot

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Additional information source

Classification of spatial data and services

Topic category

location

society

Keywords

Keyword set

keyword value

Statistical units

originating controlled vocabulary

title

GEMET - INSPIRE themes, version 1.0

reference date

date type

publication

effective date

2008-06-01

Keyword set

keyword value

statistical data

population distribution

originating controlled vocabulary

title

GEMET - Concepts, version 2.4

reference date

date type

publication

effective date

2010-01-13

Keyword set

keyword value

Statistical analysis

originating controlled vocabulary

title

IPSV Subjects List

reference date

date type

publication

effective date

2020-11-18

Geographic location

West bounding longitude

-8.80

East bounding longitude

-0.71

North bounding latitude

60.87

South bounding latitude

54.63

Extent

Extent group

authority code

code identifying the extent

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

creation

effective date

2004-02-02

date type

publication

effective date

2004-02-02

date type

revision

effective date

2021-10-04

Frequency of update

notPlanned

Quality and validity

Lineage

Centroids for data zones were originally created by the Scottish Executive's Geographic Information Service (SEGIS, now the Scottish Government's Geographic Information Science and Analysis Team, GI-SAT) in order to provide a way to link data zones to other (higher) geographic boundaries used by Scottish Neighbourhood Statistics and the wider Scottish Government community. Data zone centroids do not represent the geometric centre of the feature, but rather the population weighted centre. These points were generated using the easting, northing and populations of each output area included within the data zone. Centroids of Census Output Areas were created by taking the average grid references of all post codes in the output area, weighting them by the household count, and choosing the grid reference of the post code nearest to the average to represent the centroid of the output area. A similar method was used to calculate the data zone centroids by the following steps: 1) The easting of each output areas in the data zone was multiplied by it's population, and then the northing of each of the output areas by it's population. 2) The results for all easting and northing for each output area were then added together (based upon the data zone that they are in) to get a total easting and total northing for each data zone. 3) The average easting and northing was calculated by dividing the totals for easting and northing by the total population (of the data zone). 4) Lastly, the distance from each of the output area centroids to the average easting/northing was calculated. This was solved using the Pythagoras' Theorem, wherein the distance equals the square root of the difference in easting coordinates squared plus the difference in northing coordinates squared. Each Output Area easting was subtracted from the average easting, and in the case of negative results, multiplied by -1 to obtain a positive number. The same procedure was used to calculate the difference in northing coordinates. The Output Area coordinate pair with the shortest distance to the average was chosen to represent the centroid of the data zone, deemed to be the closest to the population centre. This dataset also includes the Small Area Population Estimates (SAPE) for data zones, as calculated by National Records of Scotland (NRS) for the years 2001 to 2011. Population estimates are usually released every November for the previous calendar year (i.e. population estimates for 2008 were released in November 2009). Each year at that time, this dataset will be updated to show the new population estimate. For more information on SAPE data produced by NRS, please see http://www.gro-scotland.gov.uk/statistics/publications-and-data/population-estimates/special-area/sape/index.html. The dataset is managed by the Scottish Government's Geographic Information Science and Analysis Team (GI-SAT), who carry out any required updates at the request of the Office of the Chief Statistician (OCS).

Conformity

Conformity report

specification

title

reference date

date type

publication

effective date

2010-12-08

degree

false

explanation

Data format

name of format

WMS

version of format

1.3.0

Constraints related to access and use

Constraint set

Limitations on public access

The following attribution statement must be used to acknowledge the source of the information: Copyright Scottish Government, contains Ordnance Survey data © Crown copyright and database right (insert year)

Constraint set

Limitations on public access

Responsible organisations

Responsible party

contact position

Geographic Information Science and Analysis Team

organisation name

Scottish Government

full postal address

Victoria Quay

Edinburgh

EH6 6QQ

United Kingdom

email address

GI-SAT@gov.scot

responsible party role

publisher

Responsible party

contact position

Data, Statistics and Outcomes

organisation name

Scottish Government

full postal address

St Andrews House, Regent Road

Edinburgh

EH1 3DG

United Kingdom

email address

neighbourhood.statistics@gov.scot

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

contact position

Geographic Information Science and Analysis Team

organisation name

Scottish Government

full postal address

Victoria Quay

Edinburgh

EH6 6QQ

United Kingdom

email address

GI-SAT@gov.scot

responsible party role

pointOfContact

Metadata date

2021-10-05T15:21:57

Metadata language

eng