重庆市骤发干旱向水文干旱的传播特征OACHSSCD

Monitoring and assessing flash droughts can significantly enhance the forecast accuracy and timeliness of hydrological droughts,providing a theoretical foundation for improved water resource management.To investigate the propagation characteristics from flash drought to hydrological drought,this study employs the pentad-scale(5-day)Standardized Precipitation Evapotranspiration Index(SPEI)and Standardized Runoff Index(SRI)to comparatively analyze the propagation features and distinctions between meteorological drought/flash drought and hydrological drought.The synergistic effects of intensity-duration during propagation are further explored.Key findings include:1)Flash drought frequency,intensity,and duration exhibit a slight increasing trend,with significant growth in western Chongqing.2)Spatially,high-incidence zones form a belt along the Yangtze River,where flash drought intensity and duration in hilly areas exceed those in mountainous regions.3)Drought propagation occurs within 1-2 months,with the intensity of flash drought propagating to hydrological drought surpassing that of meteorological drought."Low-frequency yet high-intensity"response zones exist in western and northeastern Chongqing 4)The propagation rate reaches 100％in northeastern mountainous areas,while intensity transfer shows nonlinear decay(mild flash droughts trigger moderate hydrological droughts with higher probability than moderate/severe events),revealing a specific intensity threshold that enhances propagation efficiency.