Multi-hazard risk assessment of the Great Wall relics: a case study in the Miyun District, Beijing

As a world heritage, the Great Wall is threatened by many natural disasters, such as mountain floods and debris flows. The natural disaster risk assessment of the Great Wall is of great significance to the risk management and preventive protection of the heritage. Yet, there were few systematic risk assessment frameworks for large linear cultural heritages like the Great Wall. This paper constructed a multi-hazard risk assessment model from two dimensions of hazard and vulnerability by combining with the geological and ecological environment in view of mountain flood, debris flow, and landslide. According to the risk assessment of 781 relics for the Great Wall in Miyun District, Beijing, and the analysis of spatial correlation and geographical detector, the results showed that 7.42% of relics were in the extremely high-risk zone. Most of the high-risk relics are defense towers, and more than half of them are endangered of cracking and collapsing. Relics that have strong agglomeration accounted for 18.69%, and they coincide with the Xiadian-Chengge fault zone and the inner ridge of Yanshan Mountain, indicating that the topographic environment and the distribution of faults have an important impact on the distribution of risk. This study could provide a scientific basis for the natural disaster risk management of the Great Wall and similar cultural heritages.