Draft National Wind Farm Development Guidelines - July 2010

Figure C-5
Hypothetical viewshed from a road, comprising combined viewsheds from viewpoints at regular
intervals along the road.
Source: Visual Landscape Planning in Western Australia - a manual for evaluation assessment, siting
and design, (WAPC 2007)
How do I go about it
Producing a Viewshed Map
The surface generated in the 3D computer model is used to generate individual viewshed
maps for each origin or key vantage point towards the proposed wind farm alignment at
strategic points on the wind turbine (i.e. top of hub, tip of blades, etc).
Producing a Composite Viewshed Map
Amalgamate a series of viewsheds from individual points at regular intervals along a
specified route to achieve a composite viewshed map. Note that the interval used on a
route through flat terrain should be greater than that used for undulating terrain (e.g. every
kilometre versus every 100 m), and the scale of analysis should also be taken into account.
What are the limitations of this technique
Viewshed maps are often based only on landform alone and do not take into account
elements of the landscape including vegetation, built form and other ancillary
infrastructure.
The concept of a viewshed map and what it is showing is often very hard to explain to laypeople
and the general public.
C.7.5 Photomontage
What is a Photomontage
Photomontage is the process of making a composite image by combining elements of
real imagery and 3D digitalisation (see Figure C-6).
Page 102 Draft National Wind Farm Development Guidelines – 2 July 2010