中国地理科学 ›› 2017, Vol. 27 ›› Issue (2): 325-336.doi: 10.1007/s11769-017-0866-x

• 论文 • 上一篇    

Change of Annual Extreme Water Levels and Correlation with River Discharges in the Middle-lower Yangtze River: Characteristics and Possible Affecting Factors

YE Xuchun1,2, XU Chong-Yu3, LI Yunliang2, LI Xianghu2, ZHANG Qi2   

  1. 1. School of Geographical Sciences, Southwest University, Chongqing 400715, China;
    2. Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Nanjing 210008, China;
    3. Department of Geosciences, University of Oslo, Oslo 0316, Norway
  • 收稿日期:2016-07-06 修回日期:2016-11-09 出版日期:2017-04-27 发布日期:2017-03-07
  • 通讯作者: YE Xuchun.E-mail:yxch2500@163.com E-mail:yxch2500@163.com
  • 基金资助:

    Under the auspices of the Fund of Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (No. WSGS2015003), Fundamental Research Funds for the Central Universities (No. XDJK2016C093), National Natural Science Foundation of China (No. 41571023)

Change of Annual Extreme Water Levels and Correlation with River Discharges in the Middle-lower Yangtze River: Characteristics and Possible Affecting Factors

YE Xuchun1,2, XU Chong-Yu3, LI Yunliang2, LI Xianghu2, ZHANG Qi2   

  1. 1. School of Geographical Sciences, Southwest University, Chongqing 400715, China;
    2. Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Nanjing 210008, China;
    3. Department of Geosciences, University of Oslo, Oslo 0316, Norway
  • Received:2016-07-06 Revised:2016-11-09 Online:2017-04-27 Published:2017-03-07
  • Contact: 10.1007/s11769-017-0866-x E-mail:yxch2500@163.com
  • Supported by:

    Under the auspices of the Fund of Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (No. WSGS2015003), Fundamental Research Funds for the Central Universities (No. XDJK2016C093), National Natural Science Foundation of China (No. 41571023)

摘要:

As one of the fastest developing regions in China, the middle-lower Yangtze River (MLYR) is vulnerable to floods and droughts. With obtained time series of annual highest water level (HWL), annual lowest water level (LWL) and the corresponding river discharges from three gauging stations in MLYR that covering the period 1987-2011, the current study evaluated the change characteristics of annual extreme water levels and the correlation with river discharges by using the methods of trend test, Mann-Whitney-Pettitt (MWP) test and double mass analysis. Major result indicated a decreasing/increasing trend for annual HWL/LWL of all stations in MLYR during the study period. A change point in 1999 was identified for annual HWL at the Hankou and Datong stations. The year 2006 was found to be the critical year that the relationship between annual extreme water levels and river discharges changed in the MLYR. With contrast to annual LWL in MLYR, further investigation revealed that the change characteristics of annual HWL were highly consistent with regional precipitation in the Yangtze River Basin, while the linkage with Three Gorges Dam (TGD) operation is not strong. Our observation also pointed out that the effect of serious down cutting of the riverbed and the enlargement of the cross-section area during the initial period of TGD operation caused the downward trend of the relationship between annual LWL and river discharge. Whereas, the relatively raised river water level before the flood season due to TGD regulation since 2006 explained for the changing upward trend of the relationship between annual HWL and river discharge.

关键词: extreme water level, water level-discharge relationship, double mass analysis, Yangtze River

Abstract:

As one of the fastest developing regions in China, the middle-lower Yangtze River (MLYR) is vulnerable to floods and droughts. With obtained time series of annual highest water level (HWL), annual lowest water level (LWL) and the corresponding river discharges from three gauging stations in MLYR that covering the period 1987-2011, the current study evaluated the change characteristics of annual extreme water levels and the correlation with river discharges by using the methods of trend test, Mann-Whitney-Pettitt (MWP) test and double mass analysis. Major result indicated a decreasing/increasing trend for annual HWL/LWL of all stations in MLYR during the study period. A change point in 1999 was identified for annual HWL at the Hankou and Datong stations. The year 2006 was found to be the critical year that the relationship between annual extreme water levels and river discharges changed in the MLYR. With contrast to annual LWL in MLYR, further investigation revealed that the change characteristics of annual HWL were highly consistent with regional precipitation in the Yangtze River Basin, while the linkage with Three Gorges Dam (TGD) operation is not strong. Our observation also pointed out that the effect of serious down cutting of the riverbed and the enlargement of the cross-section area during the initial period of TGD operation caused the downward trend of the relationship between annual LWL and river discharge. Whereas, the relatively raised river water level before the flood season due to TGD regulation since 2006 explained for the changing upward trend of the relationship between annual HWL and river discharge.

Key words: extreme water level, water level-discharge relationship, double mass analysis, Yangtze River