黄土丘陵沟壑区小流域治理对侵蚀产沙特征的影响

Sediment Yields from the Parallel Watersheds in the Hilly-gully Regions of Loess Plateau

以黄土丘陵沟壑区第Ⅲ副区内治理小流域桥子东沟和未治理小流域桥子西沟为对象,分析降雨、径流、泥沙资料,研究水土保持综合治理对流域侵蚀产沙、水沙关系、次降雨泥沙输移过程的影响。结果表明:水土保持综合治理的桥子东沟的年降雨侵蚀产沙显著低于未治理的桥子西沟。水土保持综合治理降低了径流平均含沙量、输沙率,桥子东沟的径流平均含沙量、输沙率比桥子西沟分别减少40%、80%。水土保持综合治理改变了次降雨径流含沙量和输沙率动态过程。治理初期,桥子东沟的径流含沙量过程都明显高于桥子西沟,桥子东、西沟输沙率在不同时间段有高有低;治理后期,桥子东沟的径流含沙量、输沙率都显著低于桥子西沟。水土保持综合治理影响小流域次降雨水沙关系。

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.