Vulnerability assessment and categorization against heat waves for the Bilbao historic area

Climate change is threatening urban cultural heritage's preservation and survival. To improve the resilience of urban systems, planning decision-making processes must consider the risks that climate change poses to heritage. Nevertheless, despite the extensive body of research on climate-related hazards, there remains a significant knowledge deficiency related to the assessment of risks that considers heat waves and historic urban sites. This study's primary objective is to use Geographic Information Systems (GIS) data to analyse how historic urban locations and heat waves interact, as both urban systems and heritage areas. Socioeconomic, cultural, governmental, and physical aspects of the system are considered for a holistic approach. Key performance indicators, criteria, and requirements pertaining to key vulnerabilities of historic urban areas are identified to undertake a vulnerability assessment methodology, and appraised using the MIVES methodology, a Multi Criteria Decision Making Methodology (MCDM), to achieve this goal. Additionally, a reduced and data-constrained evaluation is provided through a categorization, for both buildings and public spaces. The categorization process and complete methodology are discussed along with the results of its application to a GIS-based model in Bilbao's historic district (Basque Country, Spain). This study seeks to be reproducible and be a tool for future global studies.