The trends in runoff and sediment transportation in typical Loess Plateau basins and the factors causing the changes need to be clarified.

In this study, the runoff and sediment transportation data from 1960 to 2016, from hydrological stations (Wenjiachuan, Baijiachuan, Ganguyi, and Zhuangtou) based in four typical basins, were analyzed systematically using linear regression, anomaly accumulation, the Mann–Kendall test, and double accumulation curve. The characteristics of the runoff and sediment transportation and their responses to climatic and anthropogenic activities were investigated using several hydrological analytical and statistical methods.

The results indicate that both runoff and sediment transportation in the four typical basins have decreased sharply from 1960 to 2016. Since the implementation of the Grain-for-Green Project in 1999, the reduction has been more marked, in particular the runoff and sediment discharge of the Kuye River (Wenjiachuan station). Compared with the period 1960–1999, the average annual runoff and sediment discharge in 2000–2016 had decreased by 76.72% and 94.50%, respectively. Apart from the Wuding River (Baijiachuan station), an abrupt change in runoff and sediment transportation in the basins occurred within 2–7 years of the implementation of the Grain-for-Green Project.

In general, returning farmland to forests (grass) has had a more pronounced effect on the reduction of runoff and sediment in the more northerly Kuye River (Wenjiachuan station) and Wuding River (Baijiachuan station) basins, compared with the more southerly Yanhe River (Ganguyi station) and Beiluo River (Zhuangtou station) basins.