1970-2019年河南省年内降水分配非均匀性的时空演变

Spatial and Temporal Evolution of Inhomogeneity of Intra-annual Precipitation Distribution in He’nan Province During 1970-2019

[目的]分析河南省年内降水分配非均匀性的时空演变规律,为区域水资源管理提供依据。[方法]依托河南省113个气象站1970—2019年逐月降水数据,评估了降水季节性指数(PSI)的时空变化。[结果]①PSI的空间分布表明河南省北部呈现出较高的降水非均匀性,超过28%的降水集中在7月;②基于主成分分析,河南省可以划分为4个呈现不同PSI演变特征的子区域,分别为西部、中东部、北部、南部;③西部、中东部、及南部地区的PSI在1990年后呈现出一定的上升趋势,而北部地区PSI呈现出更为强烈的短期振荡;④河南省大部分地区PSI的年代际变化主要受厄尔尼诺/南方涛动(ENSO)影响;⑤与其他粮油作物相比,冬小麦产量的年际波动对PSI更为敏感。[结论]河南省年内降水分配的时空变异性较强,其与大尺度环流信号的相关性存在显著的区域差异。

[Objective]The spatio-temporal variability for inhomogeneity of intra-annual precipitation distribution was analyzed in order to provide the basis for regional water resource management.[Methods]Based on monthly precipitation data during 1970—2019 at 113 stations in He’nan Province,spatio-temporal variability of the precipitation seasonality index(PSI)was evaluated.[Results]①The spatial distribution of PSI showed that North He’nan Province had higher precipitation inheterogeneity,and more than 28%of precipitation occurred in July;②He’nan Province could be divided into four sub-regions with different temporal variations in PSI(west,central-east,north,and south areas)by using principal component analysis;③After 1990,PSI in west,central-east,and South He’nan Province showed a certain upward trend,while PSI in North He’nan Province showed a stronger short-term oscillation;④The interdecadal changes of PSI in most areas of He’nan Province were mainly influenced by ENSO;⑤The inter-annual fluctuation of winter wheat yield was more sensitive to PSI than the yield of other grain and oil crops.[Conclusion]The spatial-temporal variability of intra-annual precipitation distribution in He’nan Province was strong,and there were significant regional differences in the correlation between intra-annual distribution and large-scale circulation signals.