Periodic variation of the streamflow and sediment transport in Yan River using wavelet analysis test
XU Gao-； Zhang-Xiao-Ping-； Li-Dui
1.Colleage of Resources and Environment,Northwest Agriculture and Forestry University,2.Institute of Soil and Water Conservation,Northwest Agriculture and Forestry University,CAS,MWR:712100,Yangling,Shaanxi,China
Abstract：The periodic variation and its changing features of the streamflow and sediment transport in Yan River were studied using wavelet analysis test.The monthly data of streamflow,sediment transport from 1953 to 2000 and monthly precipitation from 1957 to 2000 were employed for Ganguyi hydrological gauging station.The results showed that precipitation,streamflow,and sediment transport had significant periodicity and their sizes were approximate.They were 3,6.5,13,and 23 years.The main period for precipitation was 3 years due to the most significant variation coefficient.For both streamflow and sediment transport,it was 23 years.On the micro scale corresponding to the period of 3 years,the annual distribution of precipitation after 1970's became uniform over the time.The three curves of the precipitation,streamflow and sediment transport became turbulent from 1970's to the beginning of the 1980's probably due to the soil and water conservation measures increased dramatically in this period.The three curves returned consistent probably due to the damage and weakening of the conservation measures after 1980's.For both the middle scale with 13 years and the macro scale with 23 years,the curves of streamflow and sediment transport turned out to be out phase,or lagged the precipitation curve in some periods.Their periodicity showed that precipitation was the main outer deriving factor for Yan River producing streamflow and sediment,however the human activities were the another important factor to influence their period changing.
于浩<sup>1</sup>； 张晓萍<sup>2</sup>； 李锐<sup>2</sup>. 延河流域径流和输沙周期变化特征的小波分析[J]. 中国水土保持科学, 2008, 6(4): 18-22.
XU Gao-； Zhang-Xiao-Ping-； Li-Dui. Periodic variation of the streamflow and sediment transport in Yan River using wavelet analysis test. SSWCC, 2008, 6(4): 18-22.
2008, Vol. 6 
