Physical vulnerability of the coastal zone under wind farms influence of the cities of Pedra Grande and São Miguel do Gostoso/RN, Brazil

This study consists of determining the physical vulnerability of the region of São Miguel do Gostoso and Pedra Grande (in northeastern Brazil) before and after wind farm installation. To perform such an investigation, an analysis of the coastline vulnerability of the aforementioned area was conducted, considering changes occurred in the past 30 years and spatially presented separately. The Natural Vulnerability Index (NVI) and Environmental Vulnerability Index (EVI) were calculated through analysis using thematic maps of geomorphology, geology, soils, vegetation, and land use and occupation variables, with their dimensionality and subjectivity determined by the execution of the hierarchical analytical process (HAP) and principal component analysis (PCA). High and very high vulnerability together showed proportions between 18 and 30% in all NVI and EVI scenarios. The Coastal Vulnerability Index (CVI) was defined using two methodologies for the three scenarios of sea level rise established by the Intergovernmental Panel on Climate Change (IPCC): the first one includes six physical or hydrodynamic variables, and the second includes, beyond these, three more variables of anthropogenic action. In all of the applied scenarios, the medium and high vulnerabilities dominated all along the coastline, with the second method being the most optimistic. We can conclude that the installation of the wind farm complex contributed to the increase of the vulnerability of the local ecosystems regarding the three investigated indices; however, it was not the preponderant factor for the determination of the CVI vulnerability degree.