Simulations demonstrating interaction between coarse and fine sediment loads in rain‐impacted flow
Simulations demonstrating interaction between coarse and fine sediment loads in rain‐impacted flow
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DOI：
10.1002/esp.1249
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发表时间：
2006-03
影响因子：
3.3
通讯作者：
P. Kinnell
中科院分区：
文献类型：
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作者：
P. Kinnell
降雨影响的水流主导着片蚀和细沟间侵蚀，在侵蚀富含养分和其他化学物质的土壤方面非常重要，这些化学物质可能对水质产生有害影响。降雨影响流中的侵蚀与雨滴分离相关，随后通过流速和雨滴影响的组合（雨滴诱导流运输，RIFT）或流动的固有能力运输分离的材料。粗颗粒倾向于通过RIFT输送，而细颗粒倾向于在没有雨滴撞击的任何帮助下输送。由于与粗颗粒有关的迁移过程并非100%有效，它会在土壤表面产生一层松散的颗粒，这层颗粒保护下面的土壤不脱落。模拟进行了建模的隆起和下游运动的细颗粒和粗颗粒从土壤表面分离的个别雨滴的影响开始与表面没有松散的材料是本。模拟结果显示，随着松散物料在床层上堆积，细料的排放量下降，细料的排放量随之增加。细料排放量的下降伴随着粗料排放量的增加。在流动中排出的粗和细物质的相对量随土壤基质表面的流速和粘聚力而变化。结果表明，各种大小的沉积物的排放量在很大程度上取决于当地的土壤，雨水和水流条件，从一种情况下推断到另一种情况的结果可能是不合适的。版权所有© 2006约翰威利父子有限公司。
Rain‐impacted flows dominate sheet and interrill erosion and are important in eroding soil rich in nutrients and other chemicals which may have deleterious effects on water quality. Erosion in rain‐impacted flow is associated with raindrop detachment followed by transport either by the combination of flow velocity and raindrop impact (raindrop‐induced flow transport, RIFT) or the inherent capacity of the flow to transport detached material. Coarse particles tend to be transported by RIFT, while fine particles tend to be transported without any assistance from raindrop impact. Because the transport process associated with coarse particles is not 100 per cent efficient, it generates a layer of loose particles on the soil surface and this layer protects the underlying soil from detachment. Simulations were performed by modelling the uplift and downstream movement of both fine and coarse particles detached from the soil surface by individual raindrop impacts starting with a surface where no loose material was present. The simulations produced a flush of fine material followed by a decline in the discharge of fine material as the amount of loose material built up on the bed. The decline in the discharge of fine material was accompanied by an increase in the discharge of coarse material. The relative amounts of coarse and fine material discharged in the flow varied with flow velocity and cohesion in the surface of the soil matrix. The results indicate that the discharge of various sized sediments is highly dependent on local soil, rain and flow conditions and that extrapolating the results from one situation to another may not be appropriate. Copyright © 2006 John Wiley & Sons, Ltd.