不同类型土壤团聚体斥水性及其对溅蚀的影响

Soil Water Repellency of Different Types of Soils Aggregate and Its Effect on the Splash Erosion

为明确土壤的斥水性特征及其对土壤溅蚀的影响,以3种不同类型及利用方式土壤为研究对象,探究了土壤斥水性分布规律及其影响因素,系统分析了土壤斥水性对土壤溅蚀的影响。结果表明:(1)耕地土壤的斥水性最低,表层土壤斥水性高于下层,黄褐土斥水性(13.15sec)高于其他类型土壤,整体上看,斥水性受到土壤机械组成和游离铁、铝氧化物的显著影响(R2<-0.40,p<0.01);(2)土壤溅蚀过程呈现为倒"V"形,即一个陡涨陡落的特点,土壤累计溅蚀量随降雨历时变化关系用对数函数可以很好地拟合(R2≥0.90,p<0.01);(3)在一定雨强范围内,斥水性对土壤溅蚀有着显著影响,斥水性越大土壤发生溅蚀的程度也越大,对数函数模型也可以很好地表达溅蚀指标随斥水性变化趋势。研究结果能为降雨侵蚀机制研究与侵蚀过程模型提供理论参考依据。

In order to explore the relationships between soil splash erosion and water repellency,three types of soils（yellow cinnamon soil,brown-red soil,latosolic red soil）under different land uses（cultivated land,forest land,waste land）were selected to investigate the variations of soil water repellency（SWR）and its effect on soil splash erosion.Main results are shown as follows：（1）The SWR was the lowest for the arable soil among the studied three land uses,and it was higher in the surface soil layers than in the subsurface.Among all test soils,the SWR was largest for the cinnamon soil（13.15 sec）.The SWR was significantly affected by soil mechanical composition and free iron aluminum oxides（R2-0.40,p 〈0.01）.（2）Soil splash erosion rate generally increased initially,and then decreased.The relationship between the cumulative splash amount and rainfall duration could be well fitted by the logarithmic function model.（3）The SWR had a significant positive effect on splash erosion under a certain range of rain intensity,also showing a logarithmic function（R2≥ 0.90,p 〈0.01）.These findings could provide theoretical reference basis for rainfall erosion mechanism research and erosion process model.