中文摘要：

为揭示不同粒径团聚体坡面溅蚀规律,以第四纪粘土发育红壤为研究对象,通过室内人工模拟降雨试验（雨强75mm/h,历时45min）研究〈0.25,0.25～0.5,0.5～1,1～2,2～5mm粒径团聚体溅蚀规律,系统分析了降雨条件下各粒径团聚体破碎、溅蚀率变化、溅蚀搬运量以及溅蚀搬运后的空间分布特征。结果表明：（1）降雨条件下团聚体粒径越大越容易破碎,除2～5mm团聚体破碎量高达96.06%外,〈2mm团聚体破碎量均小于50.00%。（2）〈0.25mm团聚体溅蚀率具有陡涨陡落特点,表土结皮发育迅速;0.25～0.5mm团聚体溅蚀率陡涨缓落,表土泥浆化过程明显;0.5～5mm团聚体溅蚀率则能保持较长时间增长,随后降低。（3）不同粒径团聚体溅蚀总量、上下坡溅蚀量与净搬运量变化趋势一致,一次降雨过程中,溅蚀搬运量峰值出现在粒径0.25～0.5mm范围内,而后随着粒径的增大逐渐降低。（4）团聚体粒径越小,溅蚀搬运后的平均重量距离越大,各粒径团聚体溅蚀量基本全部分布在半径60cm范围内。研究结果能为降雨侵蚀防治及侵蚀过程模型提供理论参考。

英文摘要：

In order to determine the effects of red soil aggregate in different particle-size（0.25,0.25—0.5,0.5—1,1—2,2—5mm）on splash erosion,a simulated rainfall experiment（75mm/h rain rate and 45 min rain time）was conducted.Aggregate breakdown,splash rates change,net splashed particles and splash spatial distribution were chosen to analyze the splash regulation.The results showed that：（1）2—5mm aggregate breakdown rate was as high as 96.06%,while〈2mm was less than 50.00%.The index of breakdown rate significantly decreased with the aggregate size increasing.（2）The splash rates of 0.25 mm aggregate skyrocketed at first,and soon collapsed,the soil surface crust developed rapidly.The splash rates of 0.25—0.5mm aggregate,which could be clearly observed to become muddy,also skyrocketed at first,but then decreased slowly.The splash rates of 0.5—5 mm aggregate kept a long time increase and also decreased slowly.（3）There were the same trends for the quantity of total splashed particles,upslope and downslope particles,net splashed particles among different size of aggregate.Splash erosion quantity within 0.25—0.5mm was the maximum,and then gradually reduced with the particle size increasing.（4）Almost all of splashed aggregates spread in the scope of 60 cm,and the mean weight distance（MWS）of small aggregate was larger than those of the bigger one.This study provided a new approach to reveal the rainfall splash erosion mechanism of red soil,which had great significant for perfection of the physical progress model of rainfall erosion.