植被调控红壤坡面土壤侵蚀机理  

Mechanisms of Grass in Slope Erosion Control in Red Soil Region of Southern China

作　　者：张思毅[1] 梁志权[1] 谢真越[1] 卓慕宁[1] 廖义善[1] 郭太龙[1] 李定强[1,2] 

机构地区：[1]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,广州510650 [2]中国科学院广州分院,广东省科学院,广州510070

出　　处：《水土保持学报》2016年第3期1-5,18,共6页Journal of Soil and Water Conservation

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)

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。The soil-rock mixed colluvial slope was selected to study the feature of sediment yield that was affected by four gravel contents（0%,20%,40%,60%） and four discharges（2 L/min ,4 L/min,8 L/min,16 L/min） in indoor artificial runoff experimental condition.The results showed that： the process of sediment yield indicated that the sediment yield overall increased first, and then decreased, reached a steady finally with erosion duration. Sediment volume increased with increasing discharge, whereas sediment concentration decreased with increasing discharge; sediment volume and sediment concentration firstly decreased and then increased with increasing gravel content at the discharges of 2 L/min and 4 L/min, existing critical gravel content （20% - 40%）, but sediment yield and sediment concentration increased with increasing gravel content at the discharges of 8 L/min and 16 L/min. According to the relationship between sediment yield rate and sediment concentration, it was indicated that the effect of gravel content on sediment yield existed critical gravel content （20% - 40%）. Gravel content and discharge could be used to predict sediment yield rate of soil-gravel mixed colluvial slope correctly, but prediction for sediment concentration was poorer. The effects of discharge were higher than gravel content.

关 键 词：植被盖度 坡面流 水力学机理 土壤抗冲性 红壤 香附子 

分 类 号：S157.1[农业科学—土壤学]