The Analysis of the Characteristics of Annual Runoff Series through Wavelet Coefficients

摘要

A runoff-sequence contains many frequencies,from the point of the wavelet transformation,they are included in different wavelet coefficients.Therefore,when a smooth wavelet function is used,changes in multi-time scale and jump characteristics of precipitation time series have been probed the tendency.Wavelet transform can clearly demonstrate all kinds of characteristics of precipitation runoff series: the strength and distribution of time scales. The monthly data used in this paper comes from Guidei hydrology station of Yellow River (1919-1994) and Yichang hydrology station of Yangtze River (1946-1976),and the yearly ones from Yichang hydrology station (1882-1984).