Acta Geographica Sinica ›› 2012, Vol. 67 ›› Issue (11): 1505-1514.doi: 10.11821/xb201211007

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Trend Analysis for the Annual Discharge Series of the Yangtze River at the Yichang Hydrological Station Based on GAMLSS

JIANG Cong, XIONG Lihua   

  1. State Key Laboratory of Water Resources and Hydropower Engineering Sciences, Wuhan University, Wuhan 430072, China
  • Received:2012-07-24 Revised:2012-08-15 Online:2012-11-20 Published:2013-01-07
  • Supported by:

    Major Program of the National Natural Science Foundation of China, No.51190094; National Natural Science Foundation of China, No.51079098

Abstract: It is very important to study the trends of the inconsistent hydrological series under the changing environments. The conventional methods of trend analysis can only be used to analyze the linear trends of the mean value of hydrological series. In this paper, GAMLSS is introduced to analyze the trends in both the annual average discharge series and the annual minimum monthly discharge series of the Yangtze River at the Yichang hydrological station. GAMLSS can detect not only the time variation of the mean value of the discharge series, but also the time variation of other statistical parameters, such as standard deviation (or coefficient of variation) and coefficient of skew. Model results indicate that the mean of the annual mean discharge series decreases linearly with time, and the annual minimum monthly discharge series do not show any significant linear trend of decrease or increase.

Key words: trend analysis, annual discharge, GAMLSS, time-varying statistical parameters, Yangtze River