不同植被覆盖防治土壤风蚀对比研究  

Study on Mechanism Between Natural Shrub-grass and Soil Wind Erosion

作　　者：王翔宇[1] 原鹏飞[1] 丁国栋[1] 尚润阳[2] 孙保平[1] 张宇清[1] 吴斌[1] 马士龙[3] 

机构地区：[1]北京林业大学水土保持学院,教育部水土保持与荒漠化防治重点实验室,北京100083 [2]海河水利委员会,天津300170 [3]中水北方勘测设计研究有限责任公司,天津300222

出　　处：《水土保持研究》2008年第5期38-41,共4页Research of Soil and Water Conservation

基　　金：国家科技支撑课题(2006BAD26B0702);国家科技支撑课题(2006BAD26B03)

摘　　要：通过对毛乌素沙地不同下垫面上风速、地表粗糙度、临界起沙风速、风沙流结构的观测,发现植被覆盖可以有效防止地表风蚀:植被盖度为40%的固定沙地近地表0.2 m高度平均风速比流动沙地降低45%,侵蚀风的持续时数降低83%,临界起沙风速提高70%,地表粗糙度提高190倍;当风沙流速度相同时,20%覆盖度的半固定沙地较流动沙地可平均降低输沙79.4%;而植被盖度为40%的固定沙地较流动沙地可平均降低输沙95.6%。实验证明,单株植物同样可以降低风速。疏透结构和透风结构的单株沙蒿分别可以使植株后0.5 m高度的风速较植株前方平沙地同高度的风速下降59.4%和19.8%。Through field investigation on wind speed,aerodynamic roughness,rate of sand transporting and the structure of wind-sand flow on different underlying surfaces,we found that vegetation cover can prevent soil wind erosion effectively.Compared the fixed sandland whose vegetation coverage is 40% to the drifting sand dune which has no coverage,the average wind speed at the height of 0.2 m reduced 45%,the time of threshold wind velocity of soil erosion kept on reduced 83%,while the threshold wind velocity of soil erosion increased 70% and aerodynamic roughness increased 190 times;Compared to the drifting sand dune,when the speed of wind-sand flow is similar,the rate of sand transporting on semi-fixed sandland reduced 79.4%,while fixed sandland reduced 95.6%.The results indicated that a single plant can reduce wind speed too.Two single Artemisia ordosica could reduce wind speed at the height of 0.5 m by 59.4% and 19.8%.

关 键 词：土壤风蚀 植被盖度 地表粗糙度 输沙率 风沙流结构 

分 类 号：S157[农业科学—土壤学]