Loading document...
Landscape and Visual Impact Methodology
This Landscape and Visual Impact Assessment has been undertaken broadly in accordance with the methodology set out in the Landscape Institute and Institute of Environmental Management and Assessment 'Guidelines for Landscape and Visual Impact Assessment' 2nd Edition (published 2002 by Spon Press).
The publication describes the approach to carrying out landscape and visual impact assessments: 'Landscape impact assessment, in common with any assessment of environmental effects, includes a combination of objective and subjective judgements, and it is therefore important that a structured and consistent approach is used. It is necessary to differentiate between judgements that involve a degree of subjective opinion (as in the assessment of landscape value) from those that are normally more objective and quantifiable (as in the determination of magnitude of change).'
The Guidelines identify the need to assess Landscape and Visual effects separately: 'Landscape and Visual assessments are separate, although linked, procedures. The landscape baseline, its analysis and the assessment of landscape effects all contribute to the baseline for visual assessment studies. The assessment of the potential effect on the landscape is carried out as an effect on an environmental resource, i.e. the landscape. Visual effects are assessed as one of the interrelated effects on population.' 'Landscape effects derive from changes in the physical landscape, which may give rise to changes in its character and how this is experienced. This may in turn affect the perceived value ascribed to the landscape. The description and analysis of effects on a landscape resource relies on the adoption of certain basic principles about the positive (or beneficial) and negative (or adverse) effects of change in the landscape. Due to the inherently dynamic nature of the landscape, change arising from a development may not necessarily be significant.'
'Visual effects relate to the changes that arise in the composition of available views as as result of changes to the landscape, to people's responses to the changes, and the overall effects with respect to visual amenity.'
The publication also identifies the role of assessments within an iterative design process:
Landscape and visual assessments are important parts of the iterative design process because they can help to avoid or minimise potential negative effects of the development and, where appropriate, can also help in seeking opportunities for landscape enhancement.
The purpose of mitigation measures are outlined within the Guidelines:
The initial stage in the assessment process is the collection of baseline data on the existing landscape and visual resource:
The methodology of the assessment stage is outlined below, including the identification of potential impacts, determining the magnitude of impacts and assessing the significance of those impacts. The methodology is divided into two sections 1) Landscape Character Assessment and 2) Visual Impact Assessment.
Once the parameters of a particular development option have been selected, a forth component, the sensitivity of the landscape resource can be determined based on the predicted landscape effects of that development scenario.
The determination of the sensitivity of the landscape resource is based upon an evaluation of each key element or characteristic of the landscape likely to be affected. The evaluation reflects such factors as its quality, value, contribution to landscape character and the degree to which a particular element or characteristic can be replaced or substituted.
Landscape Sensitivity means the ability of a particular landscape type or area to accommodate change arising from a particular development, without detrimental effect on its character. This will vary with:
For this assessment the following criteria applies:
High: A designated national or regional landscape, or quality landscape of distinct character, or landscape susceptible to relatively small change.
Medium: A landscape of distinct local significance, or moderately valued characteristics or reasonably tolerant of change.
Low: A non-designated landscape, or relatively ordinary landscape in the local context, or potentially tolerant of substantial change.
For this assessment the following criteria is applied for the sensitivity of visual receptor types with adjustment made to take account of context and location (or distance):
High Users of outdoor recreational facilities and public rights of way whose attention or interest is focused on the landscape. Communities where the development results in changes in landscape setting or valued views enjoyed by the community. Occupiers of residential properties with views affected by the development Medium People engaged in an outdoor sport or recreation other than appreciation of the landscape. People travelling through or past the affected landscape in cars, or trains or other transport routes.
Low People at their place of work whose attention may be focused on their work or activity and may be less susceptible to changes in the view.
The assessment of magnitude of visual impact considers the degree of intrusion into the view, the proportion of development seen and the distance from the viewpoint.
Substantial Adverse Where the scheme would cause a significant deterioration in the view.
The Significance of Landscape Effects is a function of both Visual Sensitivity and Magnitude of Visual Impacts. There is some subjectivity and professional judgement in determining the category of effect based on the two elements outlined above.
For the purpose of this assessment Significance of Visual Effects is classified Substantial, Moderate, Slight or Negligible and effects may be Adverse or Beneficial.
Using computer generated modelling techniques; the proposed development has been superimposed upon photographs taken from selected receptor locations with a 48mm fixed camera lens. These points are accurately located upon topographical and Ordnance Survey plans through the use of a Global Positioning System (GPS). Each viewpoint used for the photomontages has an AOD level and coordinate.
The general massing of the development has been constructed as a full scale software model simulation with the indicative mass of employment and residential buildings positioned at plateau levels indicated on the Parameters Plan. By combining this model with markers that simulate known landmarks in the scheme and virtual cameras that reproduce the actual camera positions from which the photographs have been taken it allows the image generated from the computer model to be montaged with the photographs. This allows the visibility of the new development to be assessed from a series of viewpoints. The montaged images from the model are filtered to reproduce the effect of depth-cue colour reduction and atmospheric
| Moderate Adverse | Where the scheme would cause a noticeable deterioration in the view. |
| Slight Adverse | Where the scheme would cause a minor deterioration in the view. |
| Negligible/Neutral | Where the scheme would not form a noticeable deterioration or improvement in the view. |
| Slight Beneficial | Where the scheme would cause a minor improvement in the view. |
| Moderate Beneficial | Where the scheme would cause a noticeable improvement in view. |
| Substantial Beneficial | Where the scheme would cause a significant improvement in the view. |
factors present at the time of taking the base photographs. The final model images match as closely as possible the photographs into which they have been montaged.
Copyright in submitted documents remains with their authors. Request removal
