New insights on the cyclic patterns and commensurability-based prediction of flood disasters in the Huai River Basin-Anhui

This study investigated the cyclic patterns and predictability of flood disasters in the Anhui section of the Huai River Basin, leveraging historical meteorological and disaster data spanning from Bengbu Station (1951–2023), historical flood records (1949–2023). We systematically investigated flood periodicity through variance analysis, sliding correlation analysis, Morlet wavelet analysis, and the commonality method. The results reveal significant 10-, 15-, 28-, and 30-year cycles in the dataset. Notably, the 10-year cycle in precipitation and the 30-year cycle in drought–flood levels are highlighted as primary drivers of flood dynamics. The study further constructs a predictability model integrating these periodicities, forecasting elevated flood risks during 2026–2034, with the highest probability around 2030. Additionally, we explored the climatic drivers behind these cycles, linking short-term (6- to 15-year) variations to El Niño-Southern Oscillation (ENSO) events and solar activity, and long-term (28- to 30-year) cycles to the Pacific Decadal Oscillation (PDO). These findings highlight the 22- to 32-year cycle as the primary flood modulator and underscore the need for cycle-integrated flood management strategies.