Climate change vulnerability ranking of coastal roads in Malta using multi-criteria methods

Abstract

The ranking of coastal roads according to their vulnerability to climate change is a complex issue. In order to increase the quality of life and community sustainability, the environmental and social sustainability of coastal roads must also be considered. Indicators of vulnerability are profiled, on the IPCC-based vulnerability concept and defined as a function of Climate Exposure, Sensitivity and Adaptive Capacity. These dimensions need to be considered during the ranking process and can be modelled as a Multiple Criteria Decision Making (MCDM) problem. This study proposes an approach which integrates the results of different MCDM methods to provide a ranking model for climate change vulnerability of coastal roads in Malta. This approach combines six objective weighting methods made up of eleven climate change vulnerability indicators and applies them to rank the climate change vulnerability of six coastal roads using five MCDM methods. The results indicate different rankings. Following this initial phase two other MCDM methods were used to provide a definitive ranking. The results indicate that the proposed approach can integrate the inconsistent evaluation results of different MCDM methods and produce a coherent ranking of climate change vulnerability of coastal roads. The study provides policy and decision makers with a definition of a coastal road, an inventory of such roads, a list of climate change impacts and a mathematical model that incorporates climate change vulnerability indicators. The model can be used to prioritise investment and plan climate change adaptation strategies for infrastructural works on coastal roads.