坡度和植被盖度对粉砂质河岸带坡面流侵蚀水动力特征的影响

发布时间：2018-04-24 09:00

本文选题：坡面侵蚀 + 径流冲刷　；参考：《应用生态学报》2017年08期

【摘要】：揭示坡面水流水动力参数特征对于深入了解坡面土壤侵蚀的内在机制具有重要意义.本试验在黄河下游河岸带原生坡面上,采用野外模拟径流冲刷的方法,研究了4个坡度(5°、10°、15°、20°)和3个植被盖度(0%、15%、30%)在特定放水量(15 L·min~(-1))条件下坡面薄层水流剥蚀土壤的水动力学过程,分析了径流剪应力(τ)、水流功率(ω)、径流能量(F)等水动力学参数的变化及其对坡度、植被盖度以及二者交互作用的响应差异.结果表明:在坡度和植被盖度的影响下,τ、ω和F变化规律明显,坡度不变情况下,τ随着植被盖度的增加而增加,ω和F随着植被盖度的增加而减小;植被盖度不变情况下,τ、ω和F均随坡度的增加而增加.坡度小于10°时,坡度和植被盖度的变化对坡面土壤侵蚀的影响不明显;坡度大于10°时,相同坡度条件下植被盖度越大减蚀效果越明显,相同植被盖度下坡面侵蚀量随坡度的增大而增加.τ、ω均与土壤剥蚀率呈显著的线性关系,在土壤侵蚀发生时均存在临界剪应力和临界功率;F与土壤剥蚀率则呈现良好的对数关系.双因素方差分析表明,坡度和植被盖度对τ、ω和F的影响显著,两者的交互作用对ω影响显著,但对τ、F的影响不显著.
[Abstract]:It is important to reveal the characteristics of hydrodynamic parameters for understanding the underlying mechanism of soil erosion. In this experiment, the hydrodynamic processes of thin-layer water erosion soil on the primary slope of riparian zone of the lower Yellow River were studied under the conditions of 4 slopes (5 掳~ 10 掳~ 15 掳~ 15 掳~ 20 掳) and 3 vegetation coverage under the condition of a specific water discharge rate of 15 L / min ~ (-1). The variation of hydrodynamic parameters, such as runoff shear stress (蟿), flow power (蠅), runoff energy (F), and their responses to slope, vegetation coverage and their interaction are analyzed. The results show that under the influence of slope and vegetation coverage, 蟿, 蠅 and F change obviously. When slope is invariant, 蟿 increases with the increase of vegetation coverage, and 蠅 and F decrease with the increase of vegetation coverage. Under the condition of invariant vegetation coverage, 蟿, 蠅 and F all increase with the increase of slope. When the slope is less than 10 掳, the effect of slope and vegetation coverage on soil erosion is not obvious, and when the slope is larger than 10 掳, the effect of vegetation cover is more obvious under the same slope. Under the same vegetation coverage, the erosion amount of slope increased with the increase of slope. 蟿, 蠅 showed a significant linear relationship with soil erosion rate, and there was a good logarithmic relationship between critical shear stress and critical power F and soil erosion rate at the time of soil erosion. Two-factor variance analysis showed that slope and vegetation coverage had significant effects on 蟿, 蠅 and F, and their interaction had significant effects on 蠅, but had no significant effect on 蟿 F.
【作者单位】：河南大学黄河中下游数字地理技术教育部重点实验室;河南大学环境与规划学院;
【基金】：中国博士后科学基金项目(2015T80766,2014M550382) 国家自然科学基金项目(41301197,41371195) 河南省高校科技创新团队支持计划项目(16IRTSTHN012)资助~~
【分类号】：S157

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