影响长江流域异常旱涝的因子分析

AN ANALYSIS ON CONTROL FACTORS OF DROUGHT/FLOOD IN THE CHANGJIANG VALLEY

用相关矩分析方法,研究了赤道东太平洋海温等因子与长江流域夏季旱涝之间的关系及各因子在旱涝形成中的贡献。结果表明,所选因子的前期异常变化,对长江流域夏季降水都有不同程度的影响。它们之间的关系主要通过异常旱涝年反映出来,且海温、南方涛动指数和西太平洋副高与旱涝的相关具有一定的持续性。因子综合分析表明,前期赤道东太平洋海温、南方涛动指数、西太平洋副高及长江区温度在长江流域旱涝形成中贡献较大。

The relationships between the probable control factors,such as the sea surface temperature(SST)in the equatorial Eastern Pacific and the subtropical high etc.and drought/flood in theChangjiang valley are studied by using the related moment analysis.The contribution of each fac-tor to the formation of drought/flood is also discussed.The results show that the abnormal changeof all factors in the earlier stage his influence,to a different degree,on the variation of precipita-tion in summer.The relationship is shown principally by the abnormal drought/flood years.Thecorrelation of the SST,SOI and subtropical high with the drought/flood is persistent to a certaindegree.The synthetical analysis of the factors indicate that SST,SOI,subtropical high and thetemperature in the Changjiang valley area have greater contribution to the formation of drought/flood.