Features represented in the product

OS VectorMap Local raster and vector features codes are representations of real-world objects, including buildings, roads, railways, rivers and land area. The data also includes non-topographic features, such as administrative and electoral boundaries, and cartographic text and symbols. The three GeoTIFF raster maps (Full Colour, Backdrop, and Black & White) are designed and built from the same vectors as those that form the vector Geography Markup Language (GML), GeoPackage and vector tile outputs. In order to create clear, cartographically desirable backdrops, not all features available in the vector products are in the raster output. For example, contours and administrative boundaries are only available in the vector data.

OS VectorMap Local vector data is established as six separate feature classes:

• Area: For example, building polygons and urban extents.

• Line: For example, building outlines and tunnel alignments.

• Text: For example, building and road names.

• VectorMapPoint: For example, pylons and spot heights.

• RoadCLine: For road alignments.

• RailCLine: For rail alignments.

A full list of feature classes and their associated attributes is given in the product's Technical Specification.

Within each feature class, there are several features which are represented in both the raster and vector outputs of the product, including the following:

• Buildings: Only buildings over 20m² shown. These are generalised buildings and can be made up of an amalgamation of multiple buildings. Buildings are represented as both standard and important buildings in the dataset. Glasshouses are also included, provided they are over 50m².

• Roads: A road is defined as a metalled way for vehicles. Road alignments are approximations of the road centre lines. Roads have a number of classifications in the vector data and these classifications are used to build the road depiction in the raster outputs. The product contains a full connected road system, with additional attribution to determine levels when roads are coincident with other features, for example, bridges.

• Rail: All railways are represented as lines and these lines are broken when they pass under bridges, buildings and other obstructing detail. An additional feature class has been included to enable the accurate depiction of railways in both raster and vector data. This feature class contains additional attribution for potential future rail development.

• Water: Sea, lakes, ponds, rivers and streams are depicted in vector data as both polygons and line detail and are styled accordingly in the raster outputs. Water features are broken under bridges and other obstructing detail. Tidal limits (mean high and mean low water) are also contained in the data – in England and Wales, these represent the tide limits of mean tides, while in Scotland, these represent the tide limits of mean spring tides.

• General line detail: General line detail includes a number of real-world features, including fences, hedges, walls and other minor detail. Tracks and paths are classified together along with other features as general pecked detail. General line detail and general pecked detail display as solid or pecked lines in the raster. In vector outputs, general line detail and general pecked detail are split between rural and urban areas.

• Vegetation: Represented as polygons in vector data and styled in the raster. Vegetation does not have explicit bounding features.

• Names and cartographic text: There are a number of feature codes that hold names as cartographic text; these feature codes can be found in the product's Technical Specification.

• Ornamental features: These represent landform features, such as slope symbols, flat rock scree and cliffs. In the raster, these features are represented as facsimiles of cartographic artwork, originally drawn on paper maps. In the vector, a suitable style can be applied to provide a traditional artistic representation of landform ornament. Ornament is represented in the vector data as custom landform polygons.

• Archaeological and antiquity information: This information is represented in both the raster and vector outputs.

Vector-only features

• Administrative boundaries: Lines that represents the limit of government administrative areas, for example, County, Region, Island, Parliamentary, Parish, Community and District boundaries are all contained within the vector data.

• Urban extents: These are approximations of the extents of urban development as defined by Ordnance Survey. The extents are indictive only and not necessarily aligned to ground features. They have been used to generate different urban and rural depiction in the raster output, for example, in the depiction of Restricted Local Road Access (see the product's Technical Specification).

• Contours: A contour is a line on a map that joins points of equal height. In the product, contours are represented as both index contours at 25m intervals and standard contours at 5m intervals.