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The wavelet correlative analysis of climatic impacts on runoff in the source region of Yangtze River, in China
Author(s) -
Qian Kaizhu,
Wang XuSheng,
Lv Jingjing,
Wan Li
Publication year - 2014
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.3818
Subject(s) - surface runoff , evapotranspiration , environmental science , precipitation , morlet wavelet , hydrology (agriculture) , climatology , yangtze river , wavelet , china , meteorology , geology , geography , wavelet transform , discrete wavelet transform , ecology , geotechnical engineering , archaeology , artificial intelligence , computer science , biology
The source region of Yangtze River in China is a part of Tibet Plateau where the hydrological processes are sensitive to climatic change. The impacts of precipitation, air temperature and evapotranspiration on annual runoff in the source region of Yangtze River during 1957–2009 are investigated in the time‐period domain using wavelet analysis method and multiple regression method. Annual evapotranspiration is calculated with data of precipitation and air temperature based on Takahashi's empirical equation. This approximation of actual evapotranspiration successfully matches the mean annual water balance. Significant periods of runoff, 7–8 year, 20–21 year and 42–43 year, are revealed by using Morlet wavelet. Different significant periods are found for annual precipitation, air temperature and evapotranspiration, whereas the 7–8 year and 42–43 year periods are the same of the runoff. It is indicated by wavelet correlation coefficients that the correlations between runoff and these climatic components depends on periods. Change in the summation of runoff wavelet coefficients at different period can approximately represents the change pattern of real runoff and is correlated with the wavelet coefficients of the climatic components. The correlation can be expressed with a linear multiple regression equation which indicates that the change in annual runoff is contributed by change in annual precipitation rather than change in air temperature. This relationship between runoff and climatic components are different from that in the source region of Yellow River, in China.