ENSO循环与黄河上游径流的丰枯

分析了黄河上游径流主要形成区——唐乃亥以上流域的气象和水文特性,在此基础上,根据 El Nino 现象及 La Nina 现象与黄河上游径流的丰枯的对应关系,探讨了 ENSO 事件对黄河上游径流的影响。统计结果表明,ENSO 现象与黄河上游唐乃亥以上流域的径流丰枯有着密切的关系。总体而言,伴随着 El Nino 事件的发生,黄河上游出现枯水的概率较大,而黄河上游的洪水常伴随着 La Nina 事件发生。

Relationship between ENSO Cycle and Abundant or Low Runoff in the Upper Yellow River

El Nino phenomenon is a strong signal of global weather change, and it only occurs in the Equator Pacific Ocean. However, its effect exceeds far away. According analysis to historical data El Nino phenomenon has appeared 14 times in this area since 1950's, in which the one taking place in 1997 is the strongest in the 20th century. Affected by the El Nino phenomenon in1997, it happens in 1997-1998 that the climate of the areas between from the Northern Hemisphere to the Southern Hemisphere, from Africa to Latin America changed sorely. To a great extent, the floods of the Yantse River happened in 1954 and in 1998 have some relations with the El Nino phenomenon occurred in 1951-1953 and in 1997-1998. Because of the Yellow River and the Yantse River both originated from the northeast Tibetan Plateau, then what are the responses of the precipitation and runoff in the Yellow River to El Nino phenomenon? We conclude that El Nino Phenomenon should have a close relationship with the precipitation and runoff in the Yellow River basin, and El Nino Phenomenon is the main reason bringing on the runoff in the Yellow River decreasing continuously during the period from 1920 to 1930 and since 1990 based on a large of measured data. So the influence of El Nino phenomenon to the runoff in the upper Yellow River above the Tangnag Hydrometric Station and the climate features at Tibetan Plateau are analyzed and discussed. The results show that El Nino phenomenon is one of the main factors affecting runoff in the Yellow River above the Tangnag, undoubtedly. As a result, studying the responses of runoff to the El Nino phenomenon is of very important significance to long-term runoff prediction and water resources use etc for all. In the upper Yellow River if El Nino phenomenon occurs in winter of last year or in spring of this year, the probability happening the low-flow is large in the year; if El Nino phenomenon occurs in summer, the high-flow year may be happen, and the probability happening low-flow in the next year is larger. The longer the continuous period of El Nino, the lower the runoff is. If El Nino ends in spring, the probability happening dry year will be larger. If El Nino ends in summer, the high-flow year may happen in this year. If La Nina phenomenon occurs in this year, the high-flow year may happen, and perhaps the larger floods will occurs in this year or the next year.