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

ABSTRACT This study investigates the cyclic patterns and predictability of floods in the Anhui section of the Huai River Basin using historical data from Bengbu Station (1951–2023) and flood records (1949–2023). Through variance analysis, sliding correlation, and Morlet wavelet analysis, we identified significant 10-, 15-, 28-, and 30-year flood cycles. A statistically significant 10-year precipitation cycle (F=2.14 > Fα=2.05) was confirmed, and a 550-year drought-flood series revealed a dominant 30-year cycle. Based on these periodicities, a predictability model forecasts heightened flood risks between 2026 and 2034, peaking around 2030. Analysis of climatic drivers linked short-term (6–15 year) variations to El Niño-Southern Oscillation (ENSO) and solar activity, while long-term (28–30 year) cycles were associated with the Pacific Decadal Oscillation (PDO). Wavelet analysis further resolved the flood dynamics into three stable, spatially consistent oscillations: a primary 22–32-year cycle, followed by 8–15-year and 3–7-year cycles. The 28-year scale demonstrated the highest oscillation intensity. These results establish the 22–32-year cycle as the key modulator of floods, underscoring the critical need for cycle-integrated management strategies.