APPLICATION OF WAVELET ANALYSIS IN THE STUDY OF SOIL MOISTURE VARIATION IN EASTERN CHINA
Liao Jie · Changjiang liuyu ziyuan yu huanjing · 2010
The wavelet analysis method is introduced to find out the periodicity of the soil moisture time series of North China and the Yangtze-Huai Area in Eastern China.Wavelet analysis can demonstrate the main periods of soil moisture time series,and show its time-frequency characteristics of multiple time scales.Ma Zhu-guo's 45 years retrieval soil moisture data of 0~5 cm below the surface has been chosen for this study.Its soil moisture time series are longer than some observation data,and they can retrieval the soil moisture in different areas of East China.The areas chosen for this study are North China and the Yangtze-Huai Area in Eastern China,and the climate in these areas is influenced by East Asia monsoon.The analysis results show that the soil moisture has the characteristics of multi-scales periodicity.The soil moisture in North China has the first main period of 4 years and the second main period of 14 years,and the soil moisture in Yangtze-Huai area has a main period of 4 years.