长江流域季节性干旱演变及主要粮食产量响应特征OACHSSCD

This study examined the spatiotemporal evolution characteristics of seasonal drought in the Yangtze River Basin(YRB)and their effects on the yields of major grain crops.In this study,we utilized the standardized precipitation evapotranspiration index(SPEI)and standardized yield residuals series(SYRS),in conjunction with Sen's slope estimation and the Mann-Kendall test,based on data from 89 meteorological stations and yields from statistical yearbooks in the YRB from 2008 to 2022,in order to analyze the correlation between the spatiotemporal evolution of drought and the yields of rice,maize,and legume.The results indicated that while the YRB experienced an overall trend toward wetter conditions,drought events became more frequent during summer and autumn,with the drought severity showing a gradual intensification trend,among which severe drought occurred at a frequency of 5.5％in autumn.Drought impacts were particularly pronounced in the Yalong River Basin and Dongting Lake Basin,significantly affecting rice(r=0.674,P<0.01),maize(r=0.726,P<0.01),and legume(r=0.690,P<0.01)yields within the basin.Moreover,regional variations in crop yields were significantly influenced by seasonal droughts.The study recommends that it is imperative to enhance the drought resilience of agricultural systems by optimising irrigation strategies and adjusting crop patterns,thereby improving crop growth stability under arid conditions to safeguard agricultural production security.This research provides critical scientific evidence for adaptive agricultural management and climate change response strategies in the YRB.