长江流域干旱特征及成因分析

The drought of yangze river basin and Its affecting factors

文章主要总结了学者们对长江流域干旱问题的研究成果。就长江流域的干旱特征总结分析,发现它主要体现时空的变化特征,主要变化在1980年以前,春季发生雨涝的机率相对较高,夏季发生干旱的机率较高;1980年后,与之相反;而春季发生干旱频率大值区主要集中在华中地区和四川的西南部,其中华中地区以湖南、湖北为干旱高发区。另一方面主要针对2011年发生在长江流域的干旱问题进行总结。这次的干旱特征主要表现为干旱强度强、持续时间长、影响范围广;造成这次大范围干旱的主要成因为西太平洋副热带高压偏东偏南偏弱,冷空气偏少偏弱,旱区下沉运动较常年明显减弱、再加上春季赤道中东太平洋异常偏冷、西太平洋暖池区域异常偏暖,表现为一个典型的拉尼娜年。

This essay which relies on the study of predecessor mainly summary the research findings about the drought of yangze river basin.On the one hand,mainly summary the feature of yangze river basin’s drought.Before1980,it is possible to form the rain-water logging in spring and drought in summer.While after1980,it is likely to come up drought in summer and rain-water logging in spring.At the same time,central china and the southwest of sichuan have the most chance to form drought.On the other hand,mainly aim at the drought which happened along yangze river basin in2011.Its character is strength,long time and wide range.The main reasons are the weak subtropical high in western pacific,the cold air to south and the weak downward movement.What is more,it is a typical year of La Nina,low temperature in the mid-eastern pacific of equator and high temperature in the western pacific.