An integrated visual impact assessment model for offshore windfarm development

• Offshore wind energy is a rapid growing sector in the Baltic Sea.
• A GIS based model for visual impact assessment from offshore wind farms was constructed.
• The geomorphological features of the coastal zone mitigates visual impacts from sea based infrastructure.
• The visibility analysis classifies the Lithuanian sea space into five sea distinctive seascapes.
• The visual impact maps maps are a valuable contribution to the OWE planning process.

Visual impacts belong to the most common concerns about wind energy development projects in Europe. In methodological terms, visual impact assessments are lacking in objective valuation systems capable to provide planners and decision makers with scientific – based solutions for the estimation of visual interference of offshore wind facilities with seascapes. The aim of this study is to present a GIS based model for visual sensitivity assessment from human induced landscape changes based on a case study in the Lithuanian sea, where Offshore Wind Energy (OWE) parks are under Environmental Impact Assessment (EIA) and included into the national MSP implementation process as potentially emerging future use of the sea space. The approach is composed of two models: The first model is a land–sea visibility model (LS-VisM), which assesses the cumulative viewshed of landward key observation points such as beach access points, residential and non-residential buildings and most important visitor aggregation areas in the coastal zone. In addition the model assesses environmental and socio-economic assets at highest visual impact risk from coastal and marine landscape change. The second model is a scenario based sea–land visibility model (SL-VisM), which addresses cumulative visual impacts of turbines within a wind park on the coastal zone. Both model components support decision makers on the analysis of visual impacts from any sea based infrastructure on the coastline and coastal hinterland.