厄尔尼诺与黄河流域汛期降雨洪水的关系分析

Analysis on the Relations between El Nino and Rainfall Floods Occurred in Flood Season in the Yellow River Basin

分析了1951年以来历次厄尔尼诺现象出现后黄河流域各区间汛期降水的主要特征,认为厄尔尼诺现象与黄河流域降雨洪水的关系具有以下主要特点:①在厄尔尼诺次年,黄河流域各区间汛期降水量偏多的几率较非厄尔尼诺次年要大,没有出现距平≤-50%的特少年份;②黄河中游以及兰州至托克托区间厄尔尼诺次年的汛期降雨总量偏多20%以上的几率明显大于气候概率,特别是晋陕区间偏多20%以上的年份占到46.7%;③花园口洪峰流量超过10 000 m3/s的大洪水都发生在厄尔尼诺现象出现的当年或次年;④厄尔尼诺次年黄河下游汛期降雨量正常的年份很少。

The paper analyzes the main characteristics of rainfall occurred in flood season in each reach of the Yellow River basin after having each El Nino phenomenon since 1951 and deems that the relations between El Nino phenomenon and the rainfall floods of the river basin have the following main characteristics: a) in the next year of El Nino,the probability of more precipitation occurred in flood season in each reach of the river basin would be greater than that of the next year of non-El Nino and the extremely little year of anomaly ≤-50% has never happened;b) the probability of total precipitation occurred in flood season in the upper reaches of the Yellow River and the reach between Lanzhou and Tuoketuo is 20% more than that of the probability of climate,especially the reach between Shanxi and Shaanxi,the situation of more than 20% year makes up 46.7%;c) the major floods of peak discharge greater than 10,000 m3/s occurred at Huayuankou all happened in the same year or the next year of El Nino phenomenon and;d) the situation of normal precipitation of flood season of the lower Yellow River in the next year of El Nino rarely happens.