Effects of soil and water loss control on reducing runoff and sediment transport in Yan’gou watershed of Loess Hilly region

The large-scale ecological restoration will lead to significant effects on regional eco-environment in the loess plateau. Its effect on the watershed hydrology is particularly important to understand the ecological environment changes. The objective of this study was to understand the runoff and sediment changes after soil and water conservation measures had been used in Yan’gou watershed in the loess hilly region. The data of restoration process, sediment and runoff dynamic from 1998 to 2010 were analyzed. Results indicated that the runoff-sediment in Yan'gou watershed have had a significant change after management. Although the total runoff still fluctuated with precipitation, the flood flow, sediment load and total sediment discharge decreased significantly. This tendency was consistent with the stage and methods of management in this region. Terrance and other engineering measures sharply reduced the runoff, and ecological measures not only reduced the runoff, but also led to a large amount of reduction on sediment content. Thus, we should combine engineering and ecological measures, so as to effectively control the soil erosion in loess hilly region.