溅蚀研究进展

溅蚀是水蚀的初始阶段，是雨滴对地表击打直接作用的结果，是一个动能减少，地表土壤颗粒发生位移的过程。溅蚀主要发生在坡面产生径流之前和刚产生径流时，是水蚀的主要形式之一。国内外学者对溅蚀的影响因素的研究主要集中在降雨特征、土壤特性以及地形因素等方面，其中主要影响因子包括:坡度、降雨特征、植被覆盖和土层结构。溅蚀量随坡度的增大逐渐增多，但是坡度超过临界坡度时，随坡度增大而减小；随降雨强度和雨滴大小增大而增大；地表植被对降雨有直接的再分配的过程，主要表现为截流、透流和干流3方面，当地表覆盖物超过1cm时，溅蚀可以完全消失；不同级配的土壤颗粒抗溅蚀能力不同，粒径在0.15mm附近的颗粒最容易被溅蚀，溅蚀同时随着土壤结皮厚度增大，土壤抗溅蚀能力增强。然而目前国内外对溅蚀的研究主要是在实验室模拟条件下完成的，较少有野外实地的研究，更缺乏在实际农业生产条件下的研究。所以需要在前人的基础上结合我国有些地方坡耕地较多的情况，在不同作物、作物生产方式和土地耕作方式等条件下，探讨坡耕地溅蚀规律。

Advance of Research for Splash Erosion

Splash is the first step of water erosion; it is the direct results of raindrop strike on soil; it is a process that raindrop kinetic energy is being reduced and the soil particles are being removed from here and there.Scholars researching the factors of rain splash from home and abroad focused on rainfall characters,soil characters and topography element,etc.The key factors for the raindrop splash include slope gradient,meteorology factors,plant coverage and structure of soil.Splash amount increased with rise of slope gradient,but it will decrease after the slope gradient more than a critical degree; increasing with higher intensity and larger diameter of rain drop.Surface plants could redistribute rain drop directly,which include cuting off flow,throughfall and trunk stream.If the thickness of surface covers is more than 1cm,the rain splash could be avoided.Different sizes of soil particles have specific anti-splash ability.The particles whoes diameters are around 0.15mm could be splashed most easily.Soil anti-splash ability could be improved with the increase of crust thickness.But most researches on the splash were done in simulation situation in laboratory,less under natural,and agricultural conditions.So splash researches should investigate into the patterns of rain splash under the condition of different crops,crop production approach and tillage styles in terms of the reality that slope farmlands cover a great part in some areas of China and achievments made by researches.