Analysis of the rainfall and runoff temporal variation of Jialing River during 1955-2006

Abstract
To have a better understanding of the rainfall and runoff temporal variation in Beibei station of Jialing River, Mann-Kendall test, R/S analysis method and multi-regression model were used to analyze the characteristics of rainfall and runoff in the study area. The results show that (1) rainfall in spring has remarkable descending trend, runoff has obviously downward trend in autumn and the whole year. (2) Rainfall has three fluctuation points during 50 years, which appear in 1958, 1978 and 1991, and the fluctuation points of runoff happen in 1987 and 1990, respectively. (3) Hurst coefficients of annual rainfall and runoff are both greater than 0.7, which mean a significant positive continuity in the future. (4) According to the linear regression equation established by rainfall-runoff model, the runoff in June, July and August are fitted; the results indicate that the regression model can simulate flood season runoff well.