Relationship between hydraulic characteristics and soil erosion amount on loess slope
GUO Ta-Long-； Wang-Quan-Jiu-； Wang-Li-； Fan-Jun
1.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,712100,Yangling,Shaanxi;2.Graduate School of the Chinese Academy of Sciences,100039,Beijing;3.Institute of Water Resource,Xi'an University of Technology,710048,Xi'an:China
Abstract：The relationship between hydraulic characteristics and soil erosion amount has been studied through rainfall simulator experiment on loess slope.The results showed that the average flow velocity and the Reynolds number increased as the scouring discharge increased,the Froude number decreased as the scouring discharge increased.At the same time,the overland flow changes from laminar flow to turbulent flow.When the discharge ranges from 10.1 L/min to 19.9 L/min the overland flow became to the muddy flow.The average flow velocity at the outlet increased as the sourcing discharge increased.The relation between the average flow velocity and the scouring discharge presented a power function.The unit sediment yield increased as Reynolds number increased.The relation between the unit sediment yield and the Reynolds number presented also a power function.The relationship between the unit sediment yield and the Reynolds number was determined by the range of the Reynolds number.As the Reynolds number closed to the critical Reynolds number(500),the unit sediment yield decreased linearly with the Reynolds number.This study revealed not only the mechanism of erosion on loess slope,but also was very important in ecological environment management of the Loess Plateau.
2008, Vol. 6 
