Abstract: Trend test methods, including linear regression, accumulated anomaly, Theil-Sen’s estimation and Mann-Kendall trend, were employed to respectively analyze the variation trend and abruption of runoff series measured at Xingshan gauging station in Xiangxi river watershed. Result showed that the annual runoff of Xiangxi watershed was 11.59×10⁸ m³ the annual runoff, spring runoff and autumn runoff decreased remarkably (all passed significant test at 0.05 level) however, the runoff trends in summer and winter were not significant. The abruption of annual runoff appeared in 1989, spring abruption in 1978, autumn abruption occurred in 1989, and winter abruption in 1988 there were 7 abruptions in summer. From 1965 to 1990, runoff and precipitation were consistent, which showed that the runoff variation was well associated with precipitation while since 1991, the runoff decreased with the gradual increase of precipitation, which revealed that human activity has affected runoff and the influence cannot be ignored.

Key words: Xiangxi river watershed, runoff, trend analysis, abruption analysis