Experts from TEP discuss the use of verified photomontage illustrations to support landscape and visual impact assessment (LVIA)
LVIA is often an aspect of environmental impact assessment (EIA) practice and for many proposed developments it typically comprises a substantial part of the final environmental statement (ES).
For LVIA there lies a particular challenge in providing a thorough, relevant and concise assessment of anticipated effects that clearly demonstrates how judgements have been determined.
Illustrations including maps, figures, photographs and “zone of theoretical visibility” maps are typically produced to support LVIA and can effectively interpret the baseline environment.
Verified photomontages are an additional tool used to support LVIA, illustrating the effect of a proposed development on the environment and, in particular, showing its impact on views from appropriate viewpoint locations.
A verified photomontage is a visual representation of a proposed development created by combining a photograph with a computer model of the construction.
Such photomontages are as accurate as technically possible, replicable and intended to withstand scrutiny during determination of a planning application and at public inquiry.
However, a verified photomontage does not take the place of site assessment and sound professional judgement on anticipated landscape and visual effects.
The purpose of verified photomontages
Verified photomontages can serve a number of purposes. They are useful to demonstrate the nature of effects generally, as well as those described in the LVIA. For example, photomontages can be used to illustrate what constitutes an effect with minor or moderate significance in the ES.
Verified photomontages can be used to inform the layout, shape, size and external appearance of development proposals during the iterative EIA design process.
Proposed planting can be included in the photomontage, illustrating the effect of screen planting both on completion and after a stated period of plant growth.
Photomontages can also aid discussion within the developer’s design team and consultation with the local planning authority.
Selecting appropriate viewpoints
The selection of photomontage viewpoints commonly follows field assessment work that has determined the likely effects on landscape and views. Viewpoints are usually agreed between the developer and the local planning authority.
Appropriate viewpoint locations provide a balanced representation of the range of likely effects, viewing experiences and viewers. Selecting only viewpoints close to the proposed development, where the greatest effects are anticipated, is unlikely to provide a balanced representation of visual effects. Photomontage views with screening that obscures the proposed development should also be avoided.
Public viewpoints are generally selected as they are more readily accessible and are likely to be witnessed by a greater number of people. Furthermore, public views are given greater weight than private views in planning decisions.
A photomontage viewpoint from within a private property or garden could also raise criticism that one property is considered as more important than another. Selecting a public viewpoint that also represents the view from a property, or properties, most affected by the proposed development would be more appropriate.
Ensuring accuracy
Photographs are only a representation of a view. Photomontages on which they are prepared, regardless of their accuracy, share the same limitations with regard to conveying the overall impression of the final development.
That said, it is still necessary to clearly demonstrate that a verified photomontage has been properly constructed in accordance with relevant industry guidance.
Best practice guidance on photomontage production is available from the Landscape Institute (LI advice note 01/11) and Scottish Natural Heritage (SNH) (Visual representations of windfarms: good practice guidance, 2006) – although SNH’s guidance is currently under review.
LI Advice Note 01/11 recommends that photomontages produced in support of LVIA should be based on a “replicable, transparent and structured process so that the accuracy of the presentation can be verified”.
In January 2010, the Highland Council produced visualisation standards for wind energy developments which can also be applicable to other developments. The standards were produced to enable the council to verify that photomontages submitted in support of planning applications, and contained with ESs, are accurate and clearly understood representations of the proposed development.
In 2011, the Highland Council commissioned the University of Stirling to investigate the effect of focal length on public perceptions of scale and distance in landscape photographs.
The results of this study could influence the production of photomontages, in particular, for use by members of the public. And the findings of the preliminary study are discussed by Alan Macdonald in his book Windfarm visualisation: perspective or perception?.
This article was written as a contribution to the EIA Quality Mark’s commitment to improving EIA practice.
