基于蒸散发干旱指数的子牙河流域干旱时空变化特征分析OA北大核心CSTPCDEI

To investigate spatial and temporal distribution characteristics of droughts in the Ziya River Basin,the standardized precipitation evapotranspiration index(SPEI)and standardized evapotranspiration deficit index(SEDI)were calculated based on monthly precipitation and remotely sensed evapotranspiration grid data from 2001 to 2021.The spatial and temporal distribution and trend of seasonal-scale droughts in the basin from 2001 to 2021 were analyzed using Sen slope estimation and Mann-Kendall test,and characteristic variables such as drought area,number of droughts,drought duration,and drought severity were calculated.The results indicated that SPEI has higher accuracy in identifying the onset,termination,degree,and extent of droughts in the Ziya River Basin,and it showed an overall increasing trend in the basin from 2001 to 2021,indicating a wetting trend.Furthermore,a decreasing trend of SPEI in winter was detected,showing an aridity trend,especially in Xinzhou and Yangquan cities,where there were significant aridity areas.The percentage of drought area in the basin showed a fluctuating trend,and there was a wide range of seasonal drought in some years.Summer and autumn drought areas accounted for the highest proportion,higher than 90％.In part regions of Xinzhou and Yangquan cities,the western region of Shijiazhuang City,and the northern region of Hengshui City,droughts were characterized by low frequency,long duration,and high severity,while in the Handan and Xingtai cities,the southern region of Hengshui City,and the eastern region of Shijiazhuang City,droughts were characterized by high frequency,short duration,and low severity.