JOURNAL OF NATURAL RESOURCES ›› 2016, Vol. 31 ›› Issue (12): 1971-1983.doi: 10.11849/zrzyxb.20161122

• Special Articles •     Next Articles

Variations of Extreme Meiyu Events and Flood Disasters over the Mid-lower Reaches of the Yangtze River in the Past 300 Years

ZHENG Jing-yun1, SUN Di1, 2, LIU Ke-bang1, 2, HAO Zhi-xin1, ZHANG Xue-zhen1, GE Quan-sheng1   

  1. 1. Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-10-18 Online:2016-12-20 Published:2016-12-20
  • Supported by:

    National Natural Science Foundation of China, No. 91525101 and 41671201; Key Program of the Chinese Academy of Sciences, No. KJZD-EW-TZ-G10; Grants from Institute of Geographical Sciences and Natural Resources Research, CAS, No. TSYJS04; Young Talents Program, by Institute of Geographical Sciences and Natural Resources Research, CAS, No. 2014RC101.

Abstract:

The flood disasters caused a great loss of life and property in Yangtze River Basin during June-July of 2016. Meiyu became one of the main causes of flood disasters due to its high frequency, long duration and high intensity. In this study, chronology of extreme Meiyu events since 1736 was derived from Chinese historical documents and the observational data. Furthermore, and the long-term variation characteristics of extreme Meiyu events and relationships between extreme Meiyu and El Niño events were analyzed. The general circulation patterns were diagnosed to explain how El Niño influenced extreme Meiyu. The results show that there were 44 extreme Meiyu events (including 21 mega-Meiyu events) from 1736 to 2016. The most frequent occurrences of extreme Meiyu events were detected during 1901-1920 and 1991-2000. There were 21 mega-Meiyu events over the past 300 years, whose intensities were similar to that in 2016. Closely corresponding relationships was found between extreme Meiyu events and El Niño in this period. For example, 37 of total 44 extreme Meiyu events occurred in the El Niño episodes or their following years, and 16 of total 21 mega-Meiyu events occurred in the El Niño episodes. In the El Niño years, the meridional circulations were intensified over the mid-latitudes. The water vapor transported westerly and northerly to the mainland of China. A great amount of water vapor from south intersected with the cold air from high latitudes in the mid-lower reaches of the Yangtze River, which led to continuous precipitation. Moreover, in the El Niño following years, there was a steady subtropical high system at low latitudes. The transportation path of vapor was northerly, and then the vapor fluxes increased in Yangtze River Basin. It tends to cause extreme Meiyu events under this circulation background.

Key words: El Niño, extreme Meiyu events, past 300 years, the middle and lower reaches of the Yangtze River

CLC Number: 

  • P467