植被调控红壤坡面土壤侵蚀机理

发布时间：2018-06-29 22:37

本文选题：植被盖度 + 坡面流　；参考：《水土保持学报》2016年03期

【摘要】：采用人工模拟降雨方法,研究坡度10°,15°和雨强60,120,180mm/h条件下,盖度为0,33%,67%和88%的香附子对南方红壤坡面的减沙效应及其水动力学机理。研究结果表明:香附子在红壤坡面具有良好的减沙作用,盖度为33%的香附子平均能够减少72%的土壤侵蚀;随着植被盖度的增加,土壤侵蚀量减少,减沙率增大。雨强越大,红壤坡面的植被减沙率越大。相同盖度植被的减沙率在15°坡面较在10°坡面小。香附子能够降低坡面流的流速和弗劳德数,增大达西—韦斯巴赫阻力系数。植被盖度越大,流速越小,弗劳德数越小,达西—韦斯巴赫阻力系数越大,盖度为88%的坡面的达西—韦斯巴赫阻力系数约是裸坡的7倍。坡面流流速可以通过水流能坡的0.5次幂、单宽流量0.33次幂的乘积来拟合,拟合方程的系数能够反映植被对坡面粗糙度的影响。坡面的达西—韦斯巴赫阻力系数随着植被盖度呈指数函数显著增加。植被盖度越大,土壤的抗冲性越强,植被盖度为88%的坡面的土壤临界剪切力约是裸坡的2.5倍。
[Abstract]:In this paper, the sediment reduction effect and hydrodynamic mechanism of aconite with 0 33% and 88% coverage on the slope of southern red soil were studied under the condition of 10 掳~ 15 掳rain intensity and 10 掳~ 15 掳rain intensity by artificial rainfall simulation. The results showed that aconite had a good sediment reduction effect on the slope of red soil, and the soil erosion decreased with the increase of vegetation coverage, and the sediment reduction rate increased with the increase of vegetation coverage, and the soil erosion was reduced by an average of 72% when the coverage of aconite was 33%. The higher the rain intensity, the greater the vegetation sediment reduction rate on the red soil slope. The sediment reduction rate of the vegetation with the same coverage is lower on the slope of 15 掳than on the slope of 10 掳. Aconite can decrease the flow velocity and Froude number and increase the resistance coefficient of Darcy-Weisbach. The larger the vegetation coverage, the smaller the velocity, the smaller the Froude number, the greater the resistance coefficient of Darcy Wesbach, and the greater the resistance coefficient of Darcy Weisbach on the slope with a coverage of 88% is about 7 times that of the bare slope. The flow velocity can be fitted by the product of 0.5 power of flow energy slope and 0.33 power of single wide flow rate. The coefficient of fitting equation can reflect the influence of vegetation on roughness of slope surface. The resistance coefficient of Darcy-Weisbach on the slope increases exponentially with vegetation coverage. The higher the vegetation coverage, the stronger the soil impact resistance. The critical shear force of the slope with 88% vegetation coverage is about 2.5 times that of the bare slope.
【作者单位】：广东省生态环境与土壤研究所广东省农业环境综合治理重点实验室;中国科学院广州分院广东省科学院;
【基金】：国家自然科学项目(41501295) 广东省省级科技计划项目(2013B091500077);广东省省级科技计划项目(2015B070701017) 水利部公益性行业专项经费项目(201501047)
【分类号】：S157.4

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