Impact of soil and water conservation on runoff and sediment in Yanhe River Basin
延河流域水土保持对径流泥沙的影响

The nonparametric Mann-Kendall test and the Pettitt test are used to identify evolution trends and change points in the runoff and sediment records.The Flow Duration Curve(FDC) is also used to assess the runoff and sediment response to soil and water conservation of the pre-change and post-change periods in the Yanhe River Basin in this study.The results show that the change points in sediment occurred in 1971 and 1996.The soil and water conservation measures can obviously decrease runoff and sediment,reduce the flood-season runoff and increase dry-season runoff.Compared to pre-change periods,runoff regime of Yanhe River Basin shows reduction in high flows.This paper provides a scientific basis for future water resources management and evaluation of soil and water conservation benefits for hilly and gully region of Loess Plateau.