查看更多>>摘要:In the context of global warming,escalating water cycles have led to a surge in drought frequency and severity.Yet,multidecadal fluctuations in drought and their multifac-eted influencing factors remain inadequately understood.This study examined the multide-cadal changes in drought characteristics(frequency,duration,and severity)and their geo-graphical focal points within China's north-south transitional zone,the Qinling-Daba Moun-tains(QDM),from 1960 to 2017 using the Standardized Precipitation Evapotranspiration In-dex(SPEI).In addition,a suite of eight scenarios,correlation analysis,and wavelet coher-ence were used to identify the meteorological and circulation factors that influenced drought characteristics.The results indicate the following:(1)From 1960 to 2017,the QDM experi-enced significant interdecadal variations in drought frequency,duration,and severity,the climate was relatively humid before the 1990s,but drought intensified thereafter.Specifically,the 1990s marked the period of the longest drought duration and greatest severity,while the years spanning 2010 to 2017 experienced the highest frequency of drought events.(2)Spa-tially,the Qinling Mountains,particularly the western Qinling Mountain,exhibited higher drought frequency,duration,and severity than the Daba Mountains.This disparity can be attributed to higher rates of temperature increase and precipitation decrease in the western Qinling Mountain.(3)Interdecadal variations in droughts in the QDM were directly influenced by the synergistic effects of interdecadal fluctuations in air temperature and precipitation.Circulation factors modulate temperature and precipitation through phase transitions,thereby affecting drought dynamics in the QDM.The Atlantic Multidecadal Oscillation emerges as the primary circulation factors influencing temperature changes,with a mid-1990s shift to a posi-tive phase favoring warming.The East Asian Summer Monsoon and El Nino-Southern Os-cillation are the main circulation factors affecting precipitation changes,with positive phase transitions associated with reduced precipitation,and vice versa for increased precipitation.