The prospects of reverse GIS visibility analyses for the anticipation and mitigation of landscape impacts of renewable energy projects in large scales

Conventional visibility analyses face limitations as a spatial planning tool since they can only be applied in late planning phases, when project's locations have been partly or completely determined. This is due to the fact that they require a particular location as input, in order to be implemented. Therefore, visibility analyses cannot be easily carried out in the early planning phases of projects, e.g. during multicriteria studies, in order to aid in the siting of projects; because at this stage the project location is still under investigation within an extensive area. In this work, we propose the reversal of visibility analyses as a methodological shift that can enable their use in earlier planning phases and aid in overcoming various issues associated with delayed implementation. Reverse visibility analyses use the locations of protected landscape elements as their input rather than the locations of the proposed energy works. This methodological shift allows for the a priori generation of fixed landscape-protection maps surrounding important landscape elements which enjoy the advantages of: (i) proactiveness, as they can be used to anticipate landscape impacts from earlier planning stages, while proposed projects’ locations are still under investigation, (ii) time-saving, as they only need to be calculated once within a region or country, discarding the requirement for individual visibility analysis for each new project (iii) compatibility with multicriteria studies, which are only carried out in very early planning stages, and finally (iv) potential for wider combination with participatory planning processes. The implementation of reverse visibility analysis was also investigated in practice, by developing and applying a novel method called Reverse – Zone of Theoretical Visibility (R-ZTV) analysis. The method was implemented in the regional scale in the region of Thessaly, Greece, where R-ZTV maps were formed and then used to project visual impacts from planned wind energy projects to the protected landscape elements of the region. Both from the theoretical investigation and the practical application, it was demonstrated that reverse visibility analyses, such as the proposed R-ZTV or in other formats, can strengthen the role of visibility analysis in the planning of renewable energy projects and facilitate its wider implementation. Ongoing applications in large spatial scales are also briefly presented to further showcase this potential.