Risk of Compound Typhoon Disaster Chains: Insights from Southeastern China

Abstract Typhoon disasters threaten sustainable development in southeastern China due to their complex spatiotemporal chaining and compounding effects. However, characteristics of risk and exposure of compound typhoon disaster chains remain unclear, particularly across geographic scales. This study proposed a multi-scale risk assessment framework to analyze compound typhoon disaster chains, using Fujian Province—a high-risk coastal region in southeastern China—as a case study. We quantified risks and exposures of four disaster chains: typhoon-rainstorm-urban waterlogging (TRU), typhoon-rainstorm-flood (TRF), typhoon-rainstorm-landslide (TRL), and typhoon-strong wind-storm surge (TWS), across nested scales (grid, county, city, and basin). Key findings include: (1) Pronounced spatial heterogeneity exists in Fujian Province, with compound risk hotspots dominated by TRU (216.71 km 2 ), TRF (872.43 km 2 ), and TWS (263.69 km 2 ) high-risk areas in eastern coastal areas, while inland mountainous regions are primarily affected by the TRL single chain (24,993 km 2 , 20.4% of the total area of the province); (2) Approximately one-third of the provincial population (5.69 million) and GDP (RMB 552 billion yuan) are exposed to the high-risk zones of the TRF chain, whereas the TRU chain results in twice the exposure density of TRF, forming localized hotspots; (3) High-risk areas display dual patterns of single chain dominance and compound chain aggregation, with compound chain exposure densities 38–58 times higher (at population density 15,900 persons/km 2 ) than single chain exposure density. Priority should be given to managing cascading risks of compound chains like TRU-TRF, alongside targeted interventions in multi-disaster hubs such as Fuzhou City and Jinjiang City. The findings advance our understanding of typhoon disaster risk compounding, informing targeted mitigation strategies and providing a framework for multi-hazard cascade analysis.