The Risk of Heat Waves to Historic Urban Areas. A GIS-Based Model for Developing a Risk Assessment Methodology

Climate change impacts such as extreme events and progressive global warming are threatening the conservation and livability of urban cultural heritage. Understanding climate risks on heritage should be part of policy and planning decision-making processes to increase resilience and sustainability of both social and built environmental systems. However, despite a large body of literature focusing on climate-related hazards, there is a noticeable knowledge gap regarding a holistic conceptualization of the risks in historic urban areas, which is particularly concerning in the case of the impacts of heat waves and heat urban island phenomena on urban heritage. The main goal of this study is to analyze and represent the interaction between urban spaces and heat waves via geographic information systems (GIS) data, considering the vulnerability of historic areas both as urban systems and as heritage areas. To frame a holistic approach, socioeconomic, cultural, governance (services and resources), and physical (gathering tangible characteristics of all infrastructures, elements, and buildings) aspects of the system are taken into account. To this end, key performance indicators addressing relevant vulnerable elements of historic urban areas are identified for the development of a risk assessment methodology. Complementary and as foundation for the risk assessment, a categorization of vulnerability to heat waves is proposed for both buildings and urban spaces. Here, the gathering and processing of data for the development of a GIS-based model in the historic area of Bilbao, Basque Country is presented. This work aims to serve as a basis and reference for future holistic assessments of heatwaves risks in historic urban areas worldwide.