中文摘要：

采用雨滴发生器产生雨滴，选用5种直径的雨滴在4种降落高度下，分别对5种含水量的壤土进行雨滴击溅实验，每组实验设定2个重复，分析雨滴直径以及雨滴动能对溅蚀量的影响，同时分析溅蚀量的粒径分选特征。结果表明：（1）当雨滴动能小于0．0674×10^-3J时，雨滴不能产生击溅侵蚀。在一定的雨滴直径范围内，小雨滴产生的溅蚀量较多，即小雨滴易于造成击溅侵蚀。溅蚀量随着雨滴动能的增加呈线性增长。（2）对于同种类型的土壤，溅蚀量随着前期含水量的增加而增大，存在着使土壤溅蚀量达到最大的前期含水量。土壤前期含水量与土壤抗蚀性呈负相关关系。（3）溅蚀土粒的粒径≤2mm时，其中细砂粒和粘粒含量与原土较为接近，粉粒含量远低于原状土壤，而粗粉粒含量远高于原状土壤。随着雨滴动能的增大，溅蚀土粒的分选规律变得明显，小粒径（〈0．05mm）土粒的溅蚀量随着雨滴动能的增大而减小，大粒径（〉0．2mm）土粒的溅蚀量随着雨滴动能的增大而增加。

英文摘要：

Five kinds of raindrop and four raindrop falling height were selected for raindrop splash on five kinds of loam which had different moisture content with two replicated experiments to find out the character- istics of splash reosion. The influence of raindrop diameter and raindrop kinetic energy was analyzed. The size distribution of splashed soil fragments were characterized at the same time. The result shows that. （1） The quantity of splashed soil particles was less when the raindrop kinetic energy was lower than 0. 067 4）〈 10-a J. Under certain range of raindrop diameter, the amount of splashed soil fragments was larger caused by small raindrop, which meant that raindrop with smaller was more likely to produce splash soil fragments. The amount of splashed soil particles linearly increased with raindrop kinetic energy. （2）For the same kind of soil, the amount of splashed soil particles rose with soil moisture content. Under certain soil moisture con- tent, the quantity of splashed soil fragments would reach the peak. Soil moisture content was negatively cor- related with soil erodibility. （3）The splashed fragment size distribution showed that fragments up to 2 mm were transported by raindrop impacts. The mass percentage of particles （〈0. 002 mm and 0.05-0.2 mm） were similar to that of the texted soil. The content of fragments （0. 002-0.02 mm） was far lower than that of texted soil, while the content of fragments （0.02-0.05 mm） was higher. The characteristics of size dis- tributions of splashed soil fragment was more obvious with higher raindrop kinetic energy. The amount of splashed soil particles （d0.05 mm） grew with raindrop kinetic energy. The amount of splashed soil particles （〉0.2 mm） was negatively correlated with raindrop kinetic energy.