白三叶不同部位减沙效应及其对径流水动力学参数的影响  

Effects of Different Parts of Trifolium repens L. on Sediment Reduction and Runoff Hydrodynamic Parameters

作　　者：张思毅[1] 梁志权[1] 谢真越[1] 卓慕宁[1] 郭太龙[1] 廖义善[1] 韦高玲 李定强[1,2] ZHANG Siyi;LIANG Zhiquan;XIE Zhenyue;ZHUO Muning;GUO Tailong;LIAO Yishan;WEI Gaoling;LI Dingqing(Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control;Guangdong Institute of Eco-Environmental and Soil Sciences,Guangzhou 510650, China;Guangzhou Branch of Chinese Academy of Sciences, Guangdong Academy of Sciences, Guangzhou 510070, China)

机构地区：[1]广东省生态环境技术研究所//广东省农业环境综合治理重点实验室,广东广州510650 [2]广东省科学院,广东广州510070

出　　处：《生态环境学报》2016年第8期1306-1314,共9页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(41501295);广东省科学院项目(qnjj201506;Sytz201501);广东省科技计划项目(2013B091500077;2015B070701017);水利部公益性行业专项经费项目(201501047);广东省院创新平台建设专项

摘　　要：植被是控制土壤侵蚀的关键因子,研究植被不同部位的减沙效益及机理对于水土保持、植物保护和恢复具有指导意义。以白三叶(Trifolium repens L.)和红壤为实验对象,采用人工模拟降雨的方式,在坡度15°和雨强60、120、180 mm·h^(-1)条件下,测定完整植株坡面、根系坡面和裸坡的产流产沙过程和流速,研究草本植物完整植株、冠层、根系在红壤坡面的减沙效应及其对坡面径流水动力学参数的影响。研究结果表明,盖度为85%的白三叶平均减沙效益为97.3%,根系、冠层的平均减沙效益分别为66.3%、31.0%,根系的减沙效益显著高于冠层。植被能够降低径流含沙量,尤其是降雨初期的径流含沙量。植被能够降低38.6%的坡面径流流速,其中冠层的平均减速效益为31.2%,根系的平均减速效益为7.3%,冠层的减速效益远大于根系。植被对坡面径流雷诺数影响较小,能够降低径流的弗劳德数,缓解径流流态,但坡面径流都为层流-缓流形态。植被能够显著增加坡面径流的达西-韦斯巴赫阻力系数,冠层的平均增阻效益为402.4%,根系的增阻效益为33.0%。随着雨强的增大,植被的增阻效益降低。白三叶具有良好的调控坡面侵蚀的能力,其中冠层主要通过对坡面径流的流速和阻力的影响来减少坡面侵蚀,而根系的减沙效益要大于其减速和增阻效益。植被调控坡面侵蚀的机理十分复杂,其中根系的减蚀机理需要进一步深入研究。Vegetation is a key factor controlling soil erosion, and it is of guiding significance for vegetation protection and restorationin soil and water conservation to study the effect and mechanism of sediment reduction by different parts of vegetation. Trifoliumrepens L. and red soil were chosen as experimental vegetation and soil in this study. The study was conducted under the artificialsimulated rainfall, with a slope of 15° and three rainfall intensities (60, 120 and 180 mm·h-1). The runoff and sediment process andflow velocity on slopes with entire plant, root and bare slopes were measured during the rainfall. The effect of the entire plant,canopy and root on the sediment and runoff hydrodynamic parameters was analyzed. The results show that the Trifolium repens L.with the coverage about 85% could reduce 97.3% sediment load, with 66.3%, 31.0% from the root and canopy, respectively; and thecontribution of the root is significantly higher than that of the canopy. The vegetation can reduce runoff sediment concentration,especially in the initial stage of the rainfall. The vegetation could effectively reduce the flow rate by 38.6%, with 31.2%, 7.3% fromthe root and canopy, respectively; and the contribution of the canopy is significantly higher than that of the root. The vegetation hadno significant influence on the Reynolds number, but did decrease significantly the Froude number, but the runoff was alllaminar-tranquil flow. Vegetation can significantly increase the Darcy-Weisbach friction coefficient. The mean contributions onfriction coefficient increase by canopy and root were 402.4% and 33.0% for canopy and root, respectively. The efficiency ofincreasing friction coefficient by vegetation decreased when the rainfall intensity increased. In conclusion, the Trifolium repens L.had a great effect on controlling the slope erosion. The canopy reduced slope erosion mainly through its effect on the runoff velocityand slope resistance. The efficiency of root was higher in sediment reduction than in runoff velocity redu

关 键 词：坡面侵蚀 水力学参数 红壤 根系 冠层 白三叶 

分 类 号：S157[农业科学—土壤学]