坡面草本植物对土壤分离及侵蚀动力的影响研究

发布时间：2018-06-17 17:06

本文选题：草本植物 + 土壤分离　；参考：《农业机械学报》2016年05期

【摘要】：植被是影响坡面水力侵蚀过程的重要因素,深入理解草本植物坡面不同降雨和径流特性对土壤分离的作用是研究土壤侵蚀动力学的基础。为此基于坡面土壤分离试验,通过定量测定2种草本植物草冠、根系对降雨和径流的影响,研究了不同侵蚀力作用下的土壤分离特征。结果表明,草本植物对坡面径流和泥沙具有重要的调控作用,相同覆盖度下狗尾草坡面的径流含沙量低于青蒿坡面(P0.05)。对比草本植物结构对坡面土壤分离的影响,植物根系对坡面的减沙贡献率均高于其冠层(P0.05),其中,青蒿草冠对于坡面降雨的阻滞作用高于狗尾草草冠(P0.05),而狗尾草根系的减沙效益高于青蒿根系(P0.05),这主要与草本植物叶面积指数(LAI)及根系形态分布有关,不同植物的根长密度与土壤分离率呈指数函数关系。坡面土壤分离过程受到侵蚀阻力的影响,在草本植物覆盖坡面,随着植物覆盖度的增加,颗粒阻力和波阻力均呈增大趋势。降雨侵蚀力和径流剪切力是坡面土壤分离的主要侵蚀动力,不同试验条件下草本植物对降雨和径流侵蚀力的降低值为189.21~698.92 J·mm/(m2·min)和6.27~20.38 kg/(m·s2),减弱系数分别为22.75%~84.04%和19.68%~63.97%。
[Abstract]:Vegetation is an important factor affecting the process of hydraulic erosion on slope surface. It is the basis of studying soil erosion dynamics to deeply understand the effect of different rainfall and runoff characteristics on soil separation on the slope of herbaceous plants. Based on the experiment of soil separation on slope surface, the soil separation characteristics under different erosive forces were studied through quantitative determination of the effects of two herbaceous grass crowns and roots on rainfall and runoff. The results showed that herbaceous plants played an important role in the regulation of runoff and sediment on the slope, and the sediment content in the runoff of the same coverage was lower than that of P0.05 in Artemisia annua. Compared with the effect of herbaceous plant structure on soil separation, the contribution rate of plant roots to soil separation on slope was higher than that of canopy P 0.05, among which, The inhibition effect of Artemisia annua crown on rainfall on slope was higher than that on Crowne Crowne (P0.05N), but the sediment reduction benefit of root system was higher than that of Artemisia annua root system (P0.05N), which was mainly related to the leaf area index (Lai) of herb and the distribution of root morphology. The relationship between the root length density of different plants and the soil separation rate was exponential. The soil separation process was affected by erosion resistance, and the particle resistance and wave resistance increased with the increase of plant coverage. Rainfall erosivity and runoff shear stress are the main erosion forces of slope soil separation. Under different experimental conditions, the decreasing values of herbaceous plants to rainfall and runoff erosivity are 189.21 ~ 698.92 J mm/(m2 ~ (2) and 6.27 ~ (20. 38) kg/(m / s ~ (2), respectively. The abatement coefficients are 22.75 ~ 84.04% and 19.68 ~ 63.97%, respectively.
【作者单位】：北京林业大学水土保持学院;北京林业大学北京市水土保持工程技术研究中心;
【基金】：北京高等学校青年英才计划项目(YETP0750) 国家自然科学基金项目(41271300、30900866) 中央高校基本科研业务费专项(2015ZCQ-SB-03)
【分类号】：S157.4

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