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| Effects of up-slope runoff and sediment on ephemeral gully erosion sediment and hydraulic parameters |
| Che Xiaoli1，Wang Wenlong1，2，Guo Junquan3，Han Fangfang4 |
| 1.College of Resources and Environment, Northwest A&F University, 712100, Yangling ,Shaanxi; 2.State Key Laboratory of Soil Erosion and Dryland Farming, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 712100, Yangling, Shaanxi; 3.Yan'an Vocational and Technical College,716000, Yan’an, Shaanxi；4.College of Environ Science & Engineering, Chang’an University,710064, Xi’an: China |
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Abstract The ephemeral gully erosion was an important issue and had great distribution in the Loess Plateau. The runoff and sediment from up-slope had great impacts on slope soil erosion. In this paper, its effect on down-slope ephemeral gully erosion sediment yield and hydrodynamic parameters were analyzed by water discharge scouring experiments in fields, with the designed discharge 5L/min,10L/min and 15L/min on the slope of 26°. The results indicated that the runoff from up-slope increased the flow velocity. The Reynolds number, Froude number, stream power and shearing force increased by 33%-76%, 21%-47%, 29%-72%, 18%-42% respectively, and the Daycy-Weisbach coefficient decreased by 11%-13%, which caused the increasing sediment of the ephemeral gully erosion. Except the flow velocity and Froude number, the other hydrodynamic parameters increased over the water discharge scouring time. There was a power relationship between ephemeral gully relative increment sediment yield caused by up-slope runoff and relative increment of the stream power and shearing force.
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Received: 24 January 2011
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