砾石覆盖对土壤水蚀过程影响的研究进展

 土壤中砾石的存在对水蚀过程有着重要的影响,有关砾石特别是表土砾石覆盖对土壤水蚀影响的研究结果表明,表土砾石对溅蚀分散、细沟间及细沟侵蚀等坡面侵蚀过程有重要影响:1)泥沙溅蚀分散量与砾石覆盖度呈负相关关系;2)砾石覆盖与细沟间侵蚀的关系较为复杂,这取决于表土的结构、砾石的位置和大小以及坡度等因素,当砾石嵌入结皮表土时,二者呈负相关关系,当砾石置于表土之上或嵌入具有结构孔隙的表土时,二者呈正相关关系;3)砾石覆盖对细沟间侵蚀产沙的作用效率与砾石粒径呈负相关关系,砾石置于表土之上的表土产沙量总低于砾石嵌入表土的产沙量;4)表土砾石覆盖能抑制细沟的形成,增加细沟糙度,降低细沟径流速率以及径流的侵蚀速率。鉴于砾石对水蚀过程的重要影响,RUSLE、WEPP和EUORSEM等土壤侵蚀模型预报含砾石土壤流失量时对相关参数做了修正。

Review of effects of rock fragment cover on soil water erosion processes

This paper reviewed the researches about the effect of rock fragment cover on soil erosion processes.The existing findings indicated that rock fragment cover has significant effect on splash erosion,interrill erosion and rill erosion.The relationship between rock fragment cover and the amount of sediment detached by raindrop is negative.However,the relationship between rock fragment cover and interrill sediment yield is complex which depends on top soil structure,the position and size of rock fragments.The relationship of that is positive when the rock fragments are embedded in crusting soil and is negative while the rock fragments are embedded in a top layer with structural porosity or if rock fragments rest on surface soil.The effectiveness of rock fragment cover on interrill sediment yield is negatively related to the size of rock fragments.The sediment yield of soil covered by resting rock fragments is always smaller than that of soil covered by embedded rock fragments.Rock fragments can inhibit the formation of rill,and reduce the runoff rate and erosion rate of concentration.Given that rock fragments have important influence on water erosion process,soil erosion models such as RUSLE,WEPP,and EUORSEM all proposed formula to predict the erosion process of soils containing rock fragments.