Identification and analysis the change points of hydrological process of Yingluoxia station in the Heihe river basin

In order to distinguish the change-point of hydrological process accurately, this paper adopted the annual runoff series data for 60 years of the hydrological monitoring stations of the Yingluoxia in Heihe river basin during 1947 to 2006. Difference plot curve-combined method of rank test is used to identify the change-point of hydrological process, which combined with Brown-Forsythe method, sequential clustering method, sliding F test method to verify the accuracy of variation points. At the same time, it applied for the statistical software of SPSS to analyze the changes in hydrological characteristics of the data before and after the variation points. The results showed that 1959 and 1979 were the change points in Yingluoxia station. The characteristics of trends and mutations in hydrological series reflected that natural conditions and human activities had a significant impact on the natural state of the river hydrological sequence.