Addressing Flood Risk Assessment and Heritage Conservation by Integrating HBIM and GIS: The Case Study of Castello del Valentino (Italy)

Abstract. Climate change and increasingly frequent extreme weather events pose critical threats to cultural heritage, particularly flood-prone historic sites. This study presents an integrated workflow combining Historic Building Information Modelling (HBIM) and Geographic Information Systems (GIS) for flood risk assessment and heritage conservation. The methodology is applied to the Valentino Castle in Turin, a UNESCO-listed site located along the Po River, vulnerable to recurrent flood events. A semantically rich HBIM model was developed from high-resolution point cloud data to document the architectural and material characteristics of the castle. This model was then integrated into a multi-scale 3D GIS environment to simulate various flood scenarios and assess their impact on building elements. The workflow addresses technical challenges such as BIM-GIS interoperability, semantic-geometric translation, and applying Level of Information Need (LOIN) in heritage contexts. The resulting framework allows for detailed, spatially accurate vulnerability assessments and supports decision-making for risk mitigation, preservation planning, and stakeholder communication. While Valentino Castle is the case study for this first methodological validation, the proposed method is scalable and adaptable to other heritage sites. Integrating HBIM and GIS proves to be a valuable tool for protecting cultural assets in the face of climate-induced hazards.