Journal of Geographical Sciences ›› 2018, Vol. 28 ›› Issue (8): 1039-1058.doi: 10.1007/s11442-018-1540-7

• 研究论文 •     Next Articles

Characteristics of dry-wet abrupt alternation events in the middle and lower reaches of the Yangtze River Basin and the relationship with ENSO

Lijie SHAN1(), Liping ZHANG1,2,*(), Jiyun SONG3,4, Yanjun ZHANG1, Dunxian SHE1, Jun XIA1   

  1. 1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
    2. School of Tourism Culture and Geographical Science, Huanggang Normal University, Huanggang 438000, Hubei, China
    3. Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, UK
    4. Department of Architecture, University of Cambridge, 1-5 Scroope Terrace, Cambridge, CB2 1PX, UK
  • Received:2017-12-06 Accepted:2018-02-27 Online:2018-08-10 Published:2018-08-10
  • Contact: Liping ZHANG E-mail:shanlijie0701@163.com;zhanglp@whu.edu.cn
  • About author:

    Author: Shan Lijie, PhD Candidate, specialized in extreme hydrologic events. E-mail: shanlijie0701@163.com

  • Supported by:
    National Key Research and Development Program in China, No.2017YFA0603704;National Natural Science Foundation of China, No.51339004

Abstract:

During recent decades, more frequent flood-drought alternations have been seen in China as a result of global climate change and intensive human activities, which have significant implications on water and food security. To better identify the characteristics of flood-drought alternations, we proposed a modified dry-wet abrupt alternation index (DWAAI) and applied the new method in the middle and lower reaches of the Yangtze River Basin (YRB-ML) to analyze the long-term spatio-temporal characteristics of dry-wet abrupt alternation (DWAA) events based on the daily precipitation observations at 75 rainfall stations in summer from 1960 to 2015. We found that the DWAA events have been spreading in the study area with higher frequency and intensity since 1960. In particular, the DWAA events mainly occurred in May and June in the northwest of the YRB-ML, including Hanjiang River Basin, the middle reaches of the YRB, north of Dongting Lake and northwest of Poyang Lake. In addition, we also analyzed the impact of El Niño Southern Oscillation (ENSO) on DWAA events in the YRB-ML. The results showed that around 41.04% of DWAA events occurred during the declining stages of La Niño or within the subsequent 8 months after La Niño, which implies that La Niño events could be predictive signals of DWAA events. Besides, significant negative correlations have been found between the modified DWAAI values of all the rainfall stations and the sea surface temperature anomalies in the Nino3.4 region within the 6 months prior to the DWAA events, particularly for the Poyang Lake watershed and the middle reaches of the YRB. This study has significant implications on the flood and drought control and water resources management in the YRB-ML under the challenge of future climate change.

Key words: dry-wet abrupt alternation, the middle and lower reaches of the Yangtze River Basin, spatio-temporal characteristics, La Niño