A Value-Based Risk Assessment of Water-Related Hazards: The Archaeological Site of the Sanctuary of Asklepios at Epidaurus

The accelerating impacts of climate change present critical challenges to cultural heritage, particularly in the Mediterranean region where hydroclimatic extremes are intensifying. Future estimates for the Sanctuary of Asklepios at Epidaurus, a UNESCO World Heritage Site, suggest more intense precipitation patterns, increased rainfall intensity and water-induced material degradation. This study aims to identify current and projected climate-related threats to the site and to inform adaptive strategies that safeguard both its physical integrity and its associated heritage values through a value-based approach. Opting for a heritage value-based risk assessment, the study employs a mixed-methods technical approach grounded in the Conceptual Framework for Disaster Risk Reduction of UNISDR and ICCROM’s “ABC Method” for the risk assessment of climatic threats that combines GIS-based hydrological modelling (HAND), field observations and existing material assessments with NARA Grids to link exposure, vulnerability and value loss. Results reveal intensified surface water runoff and localised water inundation threatening key monuments, particularly the Roman Odeion and the central part of the site’s ensemble, while frost-related risks are projected to decline towards 2100. The findings suggest the development of site-specific climate change adaptation that prioritises drainage enhancement, preventive conservation and continuous monitoring to preserve its Outstanding Universal Values under changing climatic conditions.