Intervisibility analysis of an offshore wind farm using GIS tools

One of Kyoto’s protocol targets is to limit greenhouse gas emissions produced by human activities through renewable energy and the conversion of wind energy into a useful form of energy (for example electricity) which is a kind of renewable source undergoing strong development. In this work, the study is focused on offshore aeolic parks. The term “offshore aeolic” indicates wind turbines installed a few miles from the coasts of seas or lakes, exploiting the exposure of strong currents. The offshore aeolic farms have some disadvantages including the impact of these generators on the landscape, but they produce a minimum visual disturbance compared to onshore aeolic farms. Environmental Impact Assessment (known as the EIA), introduced in Europe by the 377/85/EEC Directive and amended three times, in 1997 (Directive 97/11/EC), in 2003 (Directive 2003/35/EC) and in 2009 (Directive 2009/31/EC), ensures that natural resources, usability and identity of landscapes are not compromised by engineering operations. Planning applications must be accompanied by an Environmental Statement (ES), with the purpose of giving an idea about the effect that the operations will have on the local environment. One of the main aims of the ES is the understanding of the likely visual intrusion of the proposed wind farm, which necessitates the use of visual techniques. A visual technique commonly used is the intervisibility map, normally represented by a two-dimensional map, centered on the location of the wind farm. Digital Terrain Models (DTMs) are used to achieve Thematic Maps obtained with GIS software. In this paper, GIS tools are used to identify the effects of wind farms on the landscape; in particular, attention is focused on Map Algebra functions and the study of the analysis of the intervisibility of an offshore aeolic farm is