The illustrations which acompany an environmental statement are important tools in helping to present an acurate picture of what a proposal will look like, where it will be and from where it will be visible. The choice of visual material is carefully arrived at.
All the information, from the wind turbine specifications to the photomontages, helps develop a clear picture of the extent and nature of the impact of a proposed wind farm.
These illustrations can include;
- Views of existing wind farms at varying distances
- Zone of visual influence (ZVI) maps
- Visualisations and photomontages
- Descriptive maps
Zone of Visual Influence (ZVI)
This is an important tool in helping planning officers determine the areas where a wind farm or wind turbine may potentially be seen in the surrounding landscape. The map is generally used in conjunction with visualisations, photomontages and views of existing sites which may offer similar vantage points.
The ZVI is based on digital contour data which is then superimposed onto an Ordnance Survey map for clear and accurate viewing from all areas surrounding the site. It does not take any account of vegetation or intervening obstacles in the landscape and therefore represents the maximum potential visual impact of a project; this is often vindicated when photomontages are produced and impacts from a particular location may be significantly less than the ZVI had originally forecast.
As a working tool the ZVI can be used in consultation with the relevant parties to realise the final layout of the wind farm itself. Turbine locations can be adjusted to reduce the impact of the development on sensitive landscapes and centres of population. Enlarged details taken from a ZVI can help in specific circumstances where accuracy is important, for example where the potential visual impact on a village is of particular concern.
Visualisations and Photomontages
Used in conjunction with the ZVI map, visualisations and photomontages are important tools in designing wind farms that are sensitive to the local environment. Digital Terrain Models (DTM's), also known as wireframes, graphically illustrate where turbines may be seen in the surrounding landscape. The turbines are represented as black on white images and therefore will be perceived at their maximum impact, especially given the absence of any natural features such as trees and hedges etc.
The DTM's provide an efficient way of designing a site in consultation with the relevant authorities prior to the submission of a planning application to ensure that many of the major issues am resolved at an early stage. Full photomontages can then be produced for relevant locations and, if applicable, a cumulative impact assessment undertaken where applications for other sites may be of significance.
Maps
These provide the viewer with clear representations of all the relevant information required for the determination of a planning application. Such information is often site specific and each map is adapted to suit its individual purpose. Great care is taken to make the maps accurate and clear as well as visually appealing. Subjective assessments on quality of production by determining parties can detrimentally affect perceptions about an application as a whole if badly or inaccurately presented.
