Comparison of Coastal Vulnerability Index applications for Barcelona Province

The Coastal Vulnerability Index (CVI) is one of the simplest and commonly used methods to assess coastal vulnerability to sea-level rise (SLR) driven erosion and/or inundation. In this way, it is a common tool contributing to the decision-making process in long-term coastal planning and management. However, there is not a unique approach to be adopted, and existing ones can supply different information and, thus, promote different decisions. Within this context, the main goal of this paper is to compare and evaluate different methodologies to determine CVI, and to suggest the most appropriate approach that can be generically applied for coastal vulnerability assessment. For doing this, the approaches proposed by Gornitz (1991), Shaw et al. (1998), Thieler and Hammar-Klose (2000), and Lopez et al. (2016) are applied along the 160 km long the Barcelona coastline in the Spanish Mediterranean. Shaw et al.'s (1998) method appears to be the more realistic approach to assess vulnerability of the Barcelona coast while the overall vulnerability level calculated by the equation proposed by Gornitz (1991) indicate a wide variability, from highly vulnerable to a very low level of vulnerability. This study shows that the ranking tables generated from site-specific databases may not be applicable elsewhere, and indicates that it might be prudent to develop site or region-specific ranking categories to compute the overall CVI in order to provide reliable inputs to local coastal zone management initiatives. Despite the potential bias in the categorization of the overall CVI classes and their expert opinion/judgment approval requirements, CVI tools help decision makers to take the necessary actions to increase the resilience of coastal zones to SLR.