Abstract: In order to obtain the basic law of water and sediment variation in Jinghe River, we decompose series of annual runoff and sediment discharge into multiple temporal scales by EMD method, with Zhangjiashan station from 1956 to 2011 as an example. Firstly, we establish a simulation model of annual sediment discharge according to measured data and time series analysis. Then, the results show that both of the annual runoff and sediment series can be decomposed into 3 fluctuation components with different periods and a degressive tendency residual component. Furthermore, the model is of good suitability and high accuracy, and it can be used to predict annual sediment discharge. Finally, we can carry out characteristic analysis on multiple temporal scales of runoff and sediment and prediction of annual sediment discharge to provide a scientific basis for water resources planning in Jinghe River.

Key words: EMD, runoff, multiple temporal scales, annual sediment discharge, autoregressive model