中文摘要：

片蚀是坡面侵蚀演变的初始形态,揭示片蚀动力学机理,找出与片蚀关系最密切的水动力学参数对有效防治片蚀具有重要意义。该文采用人工模拟降雨方法,对黄土坡面片蚀过程动力学机理进行了研究,结果表明：1）一次降雨过程的黄土坡面片蚀模数对水动力学参数平均值响应关系的相关系数大小顺序为平均断面单位能量〉平均水流功率〉平均单位水流功率〉平均水流切应力;2）降雨过程中黄土坡面片蚀率对水动力学参数瞬时值响应关系的相关系数大小顺序是断面单位能量〉水流功率〉单位水流功率〉水流切应力;3）水流断面单位能量是与试验条件下黄土坡面片蚀动力学过程关系最密切的水动力学指标,是描述试验条件下片蚀动力学过程最好的动力学参数。试验条件下黄土坡面片蚀动力学过程的发生发展根源于坡面片蚀中水流断面单位能量的动力作用。

英文摘要：

Sheet erosion is the initial form of soil erosion evolution on a hillslope.Revealing the hydrodynamic mechanisms of sheet erosion and determining the hydrodynamic parameters closely related to sheet erosion are of importance to control sheet erosion effectively.The hydrodynamic mechanisms of sheet erosion processes on a loess hillslope were studied by a simulated rainfall experiment.Results showed that：1）In terms of the correlation coefficients for the responsive relationships of sheet erosion modulus to mean hydrodynamic parameters in a single rainfall on the loess hillslope,the mean parameters examined could be ranged in the order of mean cross-section specific energy mean stream powermean unit stream powermean stream shear stress.2）In terms of the correlation coefficients for the responsive relationships of sheet erosion rates to instantaneous hydrodynamic parameters in a rainfall process on the loess hillslope,the instantaneous hydrodynamic parameters could be ranged in the order of cross-section specific energy stream powerunit stream powerstream shear stress.3）Cross-section specific energy was the hydrodynamic index closely related to hydrodynamic processes of sheet erosion on loess hillslope under the experimental conditions and the best hydrodynamic parameter describing hydrodynamic processes of sheet erosion.Under the experimental conditions,the occurrence and development of hydrodynamic processes of sheet erosion on the loess hillslope were basically driven by the hydrodynamic functions characterized by cross-section specific energy.