OS NGD Land Use
A Lightning Talk
What are the layers in OS NGD Land Use?
The OS NGD Land Use Theme contains features that represent the geographical areas that have been identified as having a specific purpose, for example hospitals, universities, industrial parks, railway stations. It is a marked step change from OS MasterMap Sites Layer in the data that it contains. There are three feature types:
This is a polygon feature that represents a recognisable extent of a particular function or activity, a few of them are mentioned above.
What formats does the OS NGD Land Use data come in?
The OS NGD Land Use data comes in two formats, CSV and GeoPackage (GPKG)
The GeoPackage format comes ready to load into the GIS package of the users choice with different gpkg files for each layer.
The CSV format is more suited for loading into a database. All of the same feature types are accessible in csv format and all the same attribution as the Geopackage, however instead of storing the geometry in a GIS ready format, ‘Site’ for example is stored as a MULTIPOLYGON attribute all of the vertices stored as co-ordinate pairs in the text file. ‘Site Access’ and ‘Site Routing’ are stored as a POINT attribute with a co-ordinate pair for each point.
What is the new attribution?
The attribution has changed from the OS MasterMap Sites Layer product:
OS Land Use data has the OSID, TOID and Matched UPRN associated with the polygon to allow it to be linked easily with other OS datasets.
Matched UPRN replaces the Primary UPRN and is taken from the address record most likely to represent the site.
OS Land Use Tier A gives a high-level description of the main activity the site is used for.
OS Land Use Tier B gives a more detailed description of the main activity.
The Description gives a much more granular descriptive value intended for quick understanding.
Address classification codes and address primary and secondary descriptions bring additional detailed information in from our addressing data.
NLUD codes and descriptions link the OS Land Use data to industry standard categorisations
The OSID in the Site layer and the Site ID in the Site Access Location layer are the same value
The OSID the Site Routing Point layer and the Routing Point ID in the Site Access Location Layer are the same value
National Land Use Database (NLUD) attribution
In addition to the inclusion of information from OS MasterMap Topography Layer, OS MasterMap Greenspace and OS MasterMap Sites in OS NGD Land Use the new data enhancement has used categorisation from NLUD.
NLUD is designed to provide a standardised set of geo-referenced information to support sustainable development of urban and rural areas. It is used by commercial organisations and local planning authorities to create land use datasets that can influence the development and maintenance of land through town and city planning.
NLUD is a two-tier hierarchical structure with 13 order names and 41 group names with additional categories being added to the “group” names when required. It is coded using a 4-character alphanumeric designation e.g. ‘Mixed Woodland’ is coded C032. Currently NLUD is in version 4.4
Address attribution
As of September 2024 address information has been added to the site polygons drawn from our detailed addressing data. These include:
Matched UPRN: Address Classification has been taken from the OS NGD Address feature that has been matched to the Site.
Address Classification Code: Alternative land use classification that uses a code defined in the Address/BS7666 schema.
Address Primary Description: Description of the highest level of an alternative land use classification as defined in the Address/BS7666 schema.
Address Secondary Description: Description of the second level of an alternative land use classification as defined in the Address/BS7666 schema.
Address Classification Correlation: A description of how consistent the Address Classification recorded as addressLandUse_classificationCode, addressLandUse_primaryDescription and addressLandUse_secondaryDescription is when compared to the OS land use attribution of the Site.
Address Classification Source: Description of the derivation of the Address Classification recorded as addressLandUse_classificationCode, addressLandUse_primaryDescription and addressLandUse_secondaryDescription.
Address Count: The total number of OS NGD addresses that have a primary classification of ‘Residential’ , ‘Commercial’ and ‘Other’.
Source of the new attribution
Ordnance Survey surveyors and remote sensing teams have been capturing and maintaining information on land cover, land use and a more detailed level of description for over 10 years.
In the case of Land Use several classifications of Land Use have been captured but had not made it into the existing products.
This data has then been transformed and filtered to match attribution and content for existing products, such as OS MasterMap Sites Layer, however in the OS NGD data it is being published at the original, more granular level.
Currently anything in product from OS MasterMap Greenspace and OS MasterMap Sites is included in OS NGD Land Use. The TOID is present where there is definite match with OS MasterMap Sites, if no match is found then the TOID will not be present.
In addition to these, Residential polygons have now been included which have been generated from an algorithm rather than from surveyor or remote sensing capture.
Address classifications and descriptions have been derived from an analysis of the attribution of NGD Address information that falls within the extent of the Site.
Coverage comparison
The OS NGD Land Use data has all the polygons that were previously in OS MasterMap Sites Layer and OS Open Greenspace – but has significantly more new polygons that have been added in.
At the time of launch of the OS NGD there are:
46,124 polygons in OS MasterMap Sites Layer
149,588 polygons in OS Open Greenspace
24,352,168 polygons in OS NGD Land Use
It is worth noting, as with OS MasterMap Sites Layer, these polygons do not represent a legal extent, more the extent of how the land is used. This is particularly relevant to the new Residential polygons.
Classification comparison
Alongside the increase in number of polygons is the increase in the classifications in the data.
OS MasterMap Sites Layer has 7 groups broken into 40 functions
OS Open Greenspace has 10 functions
OS NGD Land Use has 360 descriptions
For example:
OS Open Greenspace has Golf Course
OS NGD Land Use has: Golf Centre, Golf Clubhouse, Golf Course and Golf Driving Range
Why do sites appear ‘stacked’ in OS NGD Land Use?
It is possible to have multiple entries for a site for OS Land User Tier B.
An Education site in OS Land Use Tier A may have multiple Tier B land uses, for example Secondary Education and Further Education.
However, it is not possible to have stacked entries for OS Land Use Tier A for a site. So, if an Education site also contains a sports facility two polygons will exist for the same site; one for the Education site and another for Sport Attraction Or Facility.
Complete Land Use coverage
The Land Use theme does not give a complete coverage of Land Use. It has a coverage of sites by their function (health, education, residential and so on), but does not currently cover things like roads, rail and fields..
To achieve a complete coverage of features with Land Use attribution requires combining elements from: Land Use, Buildings, Land, Structures, Transport Features and Water Features
It is also of note that some of the newly added sites (such as residential) are not fully complete at launch and that work is continuing on them.
Links that may be useful:
This content has been developed from what was originally a Lightning Talk PowerPoint slide set. These slides are available to PSGA members to view and download from the PSGA members area of the OS website
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