4. Using GIS to inform the SEA
In order to effectively identify, collate and assess key environmental issues and constraints along the route, the SEA has adopted a GIS (Geographical Information Systems) mapping approach.
SEA Scoping identified the locations of features and constraints within 1km of the current A9, to provide a baseline dataset. Using GIS meant that a range of indicative corridor options could be compared, in terms of the relative levels of environmental risk/ issues within each proposed corridor option footprint.
As alternative corridor options were eliminated via the sifting process described below, the GIS dataset was further refined to focus in on identifying the key issues within 200m of shortlisted options.