Building‐Scale Flood Hazard Modelling for Risk Assessment of Cultural Heritage

ABSTRACT Flooding is among the most frequent natural hazards threatening cultural heritage sites, yet current flood hazard studies often operate at urban or regional scales. While building‐scale damage models exist, they generally rely on flood depth inputs from large‐scale inundation models, inputs that may fail to capture the internal complexity of heritage buildings. This paper presents a 2D building‐scale flood hazard modelling approach designed to improve risk assessment, management, and adaptation for cultural heritage buildings. The method incorporates detailed architectural and structural features—such as basements; openings; uneven floor levels; and interior spatial layout—to simulate internal flood dynamics. The methodology is applied to the Marini Museum in Florence, Italy. An offline‐coupled hydraulic model is used in conjunction with a 2D urban‐scale flood model to simulate floodwater ingress, internal flow patterns, and the effects of mitigation measures. Our results indicate that relying solely on urban‐scale flood maps leads to substantial overestimation of internal flood depths, whereas the building‐scale model represents inundation processes within exhibition spaces. Such approach provides a more robust foundation for risk assessment and mitigation planning that supports heritage managers in the correct placement and display mode for vulnerable artworks, thanks to a risk classification of exhibition spaces. Future work will address model validation and extend this approach to heritage buildings with multiple levels under a variety of flood scenarios.