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River water and sediment characteristics are the main index reflecting the surface hydrological cycle process and soil erosion, and is of great significance to water resources and water ecological environment in the basin. In recent years, influenced by human activities and natural conditions, soil erosion in many watersheds is serious. With the population and economic development, demands for resources and influence on environment by human activities are increasing, and the impact of water and sediment disasters on social and economic development is increasingly prominent and their consequences are closely related to people’s quality of lives. Human activities in Xiang River Basin have a significant impact on the change of runoff and sediment discharge in Xiang River. Through applying the Mann-Kendall test, Pettitt test, and double cumulative curve, we analyzed the relationships between human activities (e.g. water-soil conservations, reservoir constructions, etc.) and annual runoff, flood season runoff as well as non-flood season runoff and sediment transport of the mainstream and tributaries of Xiang River from 1953 to 2014. Among them, the main control stations of the main stream include the Laobutou station in the upper stream, Hengyang station in the middle stream and Xiangtan station in the lower stream. The main representative control stations of the tributaries include Ouyanghai station in Chongling River, Shenshantou station in Zheng River, Ganxi station in Mi River and Daxitan station in Lu River. Results indicated that annual runoff and flood season runoff at main-stream and tributaries stations showed a strong correlation (R2=0.83 in Xiangtan station) with sediment loads, while the correlations were weak in non-flood seasons after 1990. Before 1990, the runoff and sediment loads at main stream stations were basically fluctuating. After 1990, the runoff at main stream stations showed an increasing trend, while the sediment discharge showed a decreasing trend at those stations, and particularly mutated slightly at Laobutou station. Except for several stations, the mutation years and the variations of the runoff and sediment discharge at tributary stations were consistent overall. Water-soil conservations and reservoir construction were verified to be main factors leading to the decrease in sediment discharge in Xiang River basin. Compared to tributary basin, the water-soil conservations had a more significant impact on the reduction of sediment discharge in the main stream of Xiang River. Moreover a strong correlation between reservoir constructions and sediment discharge reduction was found at the main streams as well as tributaries. According to the abrupt change point of sediment transport in Xiang River Basin in 1987 and 1997, the long series of data were divided into three periods: Period A ( 1960-1987 ), Period B (1988-1996) and Period C (1997-2013). Without considering the influence of temperature change, the contribution rate of rainfall and human activities to the reduction of sediment discharge can be calculated by the cumulative slope change rates. Compared with period A, the contribution rate of human activities such as soil and water conservation and reservoir sediment interception to the reduction of sediment transport in periods B and C was 88.58% and 94.01%. That was, human activities were the main factors for the reduction of sediment transport. [ABSTRACT FROM AUTHOR]