Explanation of KeySCAPE Visual Analysis and its Purpose


You wish to know when you should use the Visual Analysis (Single / Multiple View Point) and how to interpret the results.


Two options are available and the purpose of each are explained below:

Single View Point - maps areas that are visible from a single observation point, or alternatively, show areas that can view a selected point

Multi View Point - determines what areas of a terrain are visible from a number of viewpoints. Typically, these viewpoints are located in a linear fashion, such as when travelling down a road. The results show the total area that is visible from all points and does not generate a "heat map" of instances a point is visible from each point of the assessment. If this is required, run a separate Single View Point analysis from each point, changing the layer and/or colour of result so you can quickly identify the frequency, based on multiple overlays.

In both cases, the assessment is from the location(s) defined above the surface model and the eye-level/height specified. The result will show what is visible, at that 3D plane within the model.

Example of Single View Point analysis from the observers position (red dot) in the model

The assessment shows what is visible to the first point of intersection with the surface model at the specified eye-level/height and does not indicate what is viewable above and beyond the first visual barrier, such as distant features or areas of the surface model that are visible above eye-level.ViewShed.JPG

Example of Single View Point analysis showing what is visible at the observers eye-level but not above or beyond the view plane



The view analysis can be useful to provide an initial assessment of key areas in the landscape and where further detailed visual assessments may be necessary. Please be aware that this goes not comply with the latest zones of theoretical visibility (ZTV)/LVA/LIVA) methodologies and is not recommended for use at public inquiry or to resolve legal challenges.