摘要
为了解不同利用方式对呼伦贝尔草甸草原抗风蚀能力的影响,采用植被调查结合风洞实验的方法对不同利用方式条件下的草甸草原植被变化和草甸草原原状土的抗风蚀能力进行了研究.结果表明,草甸草原不同利用强度条件下临界风蚀风速(v)随植被盖度(Cover)的变化基本服从二次幂函数关系.随着利用强度的增加,植被盖度降低,在同样风速条件下(大于临界风蚀风速),风蚀率迅速增加.较轻的利用强度下,当植被盖度保持在63%时,在风速为25 m/s条件下风蚀率也很小,而当植被盖度〈35%时,在风速为20-25 m/s条件下,风蚀率随植被盖度的下降迅速上升.草甸草原区的免耕农田由于完全失去植被的保护,每分钟狂风(25 m/s)造成的土壤风蚀量达到682.1 kg/hm^2,接近1 a的土壤平均生成量(1000 kg/hm^2).
In order to analyse the effects of the human disturbances to the ability of anti-wind erosion of the Hulunbuir meadow grassland, the methods of vegetation investigation and the wind tunnel experiment were made to research the changes of vegetation and the abilities of antiwind erosion of meadow grassland under different using patterns of meadow grassland. The results indicate that, under different grazing intensities of meadow grassland, the critical wind velocity of soil erosion (v) changes with the vegetation cover according to the relation of second power function. Along with the grazing intensities increasing and the vegetation cover reducing, the velocity of soil erosion rapidly increased on the condition of similar wind velocity which is speedier than the critical wind velocity of soil erosion. When the meadow grassland is mildly grazed which the vegetation cover maintains 63 %, the velocity of soil erosion is small even there is gale that the wind velocity reach 25 m/s. When the vegetation cover of meadow grassland reduced to less than 35%, the velocity of soil erosion rapidly increased with the vegetation cover's reducing on the condition of the wind velocity is among 20-25 m/s. And owing to the no-tillage cropland of meadow grassland is completely far from the protection of the vegetation, the soil wind erosion quantity achieves 682.1 kg/hm^2 in a minute when the wind velocity is 25 m/s, which approaches the average formation quantity of soil ( 1 000 kg/hm^2)in a year.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2008年第5期1394-1399,共6页
Environmental Science
基金
国家重点基础研究发展规划(973)项目(2007CB106806)
国家高技术研究发展计划(863)项目(2006AA10Z241)
国家科技支撑计划项目(2006BAC01A12)
关键词
草甸草原
土壤风蚀
利用方式
风洞实验
meadow grassland
soil wind erosion
land use patterns
wind tunnel experiment