海河流域极端降水时空变化规律及其与大气环流的关系

Temporal and Spatial Variations of Extreme Precipitation in Haihe River Basin and Its Relationship with Atmospheric Circulation Indexes

为了解海河流域极端降水时空变化规律,基于海河流域40个气象站1960~2016年逐日降水资料,采用线性回归、M-K趋势检验法、Pearson相关性分析法,分析了海河流域近57年来10个极端降水指数的时空变化及其与大气环流的相关性。结果表明,除了持续干期(CDD)和持续湿期(CWD)外,大多数极端降水指数多年平均值在空间上呈自东南向西北减少的分布规律,CDD呈现自北向南减少的规律,CWD呈现自东南向西北增加的规律;在时间变化上,所有极端降水指数均呈下降趋势,只有最大一日降水量(RX1day)的下降趋势显著;在空间变化上,除中雨日数(R10mm)和降水强度(SDⅡ)呈上升趋势的站点与呈下降趋势的站点个数相同外,多数站点各极端降水指数呈下降趋势;除CDD与其他极端降水指数相关性较弱外,各极端降水指数的变化具有较好的一致性;除CWD外,极端降水指数与厄尔尼诺—南方涛动(ENSO)现象关系密切,而AO(北极涛动)和NAO(北大西洋涛动)是CWD变化的重要因素。研究成果对于海河流域水灾害防治及水资源配置有重要意义。

In order to understand the temporal and spatial variation of extreme precipitation in the Haihe River Basin,based on the daily precipitation data from the 40 stations(1960-2016)in the Haihe River Basin,the methods of linear re-gression,Manner-Kendall trend analysis and pearson correlation analysis were used to analyze the spatial-temporal variation of 10 extreme precipitation indexes in the past 57 years and the relationships between extreme precipitation indexes and atmospheric circulation indexes.The results show that apart from continuous dry days(CDD)and continuous wet days(CWD),the multi-year average of the most extreme precipitation indexes decreases from southeast to northwest in space,and CDD decreases from north to south,but CWD increases from southeast to northwest;For the temporal varia-tion,all the extreme precipitation indexes show a downward trend,but only the maximum daily precipitation(RX1day)has a significant downward trend;For the spatial variation,except for R10mm and SDII having the same uptrend stations and downtrend stations,most stations show a downward trend;The CDD and other extreme precipitation indexes have a weak relationship,but the variation of most precipitation indexes is consistent;Apart from CWD,the extreme precipitation index is closely related to the El Nino-Southern Oscillation(ENSO),while AO(Arctic Oscillation)and NAO(North Atlantic Oscillation)are important factors to cause the variation of CWD.The research results are of great significance for prevention of water disasters and control of water resources allocation in the Haihe River Basin.