Nature of data: showing the extent of areas visible from a range of landscape-scale polygons and view points.

Purpose of data: To assist strategic site choices when planning visually prominent development types. A web page with general introduction and links to map images produced from the data is available from Natural Resources Wales. This is new data output, believed to be seminal for Wales.

Resolution and extent: The visibility mapping uses a 30m resolution open-source digital terrain model for the whole of Wales, out to maximum viewing distance of 35km, including overlaps to/from England where relevant. The 30m digital terrain model was sourced from the Shuttle Radar Topography Mission (Van Zyl, 2001) and processed using the Quantum GIS plugin developed by Cuckovic (2016). See page 23 of technical report (via the link above) for more detail.

Types of data: Data comprises GIS files, a selection of thematic map images created from the GIS, a technical report and user guidance. Output types are (1) zone of theoretical visibility (ZTV); (2) height of object before it is visible (HOBV). Geographical units from which these calculations were run are (a) Key iconic view points to or from nationally designated landscapes – 200 points showing ZTV and HOBV; (b) The visible settings of nationally designated landscapes – 9 large polygons in or affecting Wales, showing ZTV, HOBV; and (c) The visible settings of LANDMAP Visual and Sensory Aspect Areas, 1920 polygons showing ZTV only. Additional derived maps arising from the data for (b) are: ‘heatmaps’ indicating relative concentrations of visibility, and a combined national map showing the pattern of coverage of where there is visibility from a designated landscape.

Caveats on use: The data is designed for strategic planning and site selection use only. It is quantitative data on visibility and does not itself indicate a qualitative measure of visual sensitivity. It does not replace the need for (i) more detailed site and development-specific zone of theoretical visibility mapping evidence and (ii) landscape and visual impact assessment, as part of a development consenting process.

Attribution Statement

Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.