Analysis of runoff change trend using hydrological time series method

This paper gives an introduction to a number of hydrological time series methods, including run test method, Mann-Kendall statistical testing method, cumulative anomaly method and cloud model. These methods are applied in the runoff change trend analysis in Yichang station, which is located at the main stream of the upper reache of Yangtze River. The result shows that, Mann-Kendall method not only deals with trend test, but also gives the mutation point, points out the mutation area, and combined with cloud model, it can give the uncertainty of the trend quantitatively. The Mann-Kendall method also provides a new means and a quantitative method for the uniformity and stability of different time series runoff.