Sediment yields from the parallel watersheds in the hilly-gully regions of Loess Plateau

The Qiaozi-East watershed with management and Qiaozi-West watershed without management at the third sub-region of Loess Plateau were selected as studying areas. The rainfall, runoff and sediment data were used to study the effects of soil and water conservation management on sediment yields, runoff-sedimentation relations, and sediment delivery processes. The annual sediment yields of Qiaozi-East watershed were considerably lower than those of Qiaozi-West watershed. The mean sediment contents in runoff and mean sediment delivery rates from Qiaozi-East watershed were 40% and 80% less than those from Qiaozi-West watershed respectively. Soil and water conservation management altered the sediment contents and sediment delivery processes. At the early stage of the practice, the sediment contents from Qiaozi-East watershed were higher than those of Qiaozi-West watershed, but the sediment delivery rates were more or less than those of Qiaozi-West watershed. With years of management, the sediment contents and sediment delivery rates from Qiaozi-East watershed were lower than those from Qiaozi-West watershed. Soil and water conservation management altered the runoff and sediment relations.