Evaluating visual occupancy of energy and production facilities: the update of r.wind.sun and the QGIS plugin

Visual occupancy of impactful elements on landscape has always been subject of interest across various time periods. This parameter is crucial for planning activities and is as important as other factors (for example geological assets and the presence of protected zones) because it infers directly on citizens’ perception of the landscape, influencing consensus. r.wind.sun is a script for GRASS GIS originally aimed to evaluate the visual occupancy of windfarms and photovoltaic panels with respect to the human field of view. The project, initially conceived in 2014, it has since been updated to the latest version of GRASS GIS and split into two parts to account for the different field-of-view dimensions and minor other changes. This paper describes the update process, along with applications of the code to assess the visibility of specific sites. Moreover, the scripts have been ported in QGIS to exploit its user friendly graphical user interface. Once the code generated the visibility areas, using the QGIS it is possible to examine them in detail by means of zonal statistics to evaluate the visual occupancy of an existing site or rank the visual impact of potential future sites. An example of analyses on aquaculture sites is also summarised.