秦富仓1,2 余新晓1 张满良3 谢媛媛1
QIN Fucang 1,2,YU Xinxiao1 ,ZHANG Manliang 3,XIE Yuanyuan 1
1Key Laboratory of Soil and Water Conservation and Desertification Comb
ating of Education Ministry,College of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;2Inner Mongolia Agriculture University,Huhhot 010019;3Tianshui Controlling and Supervising Bureau of Yellow River Soil and Water Conservation,Tianshui 741000,China
摘要: 从坡面水动力学角度研究了坡面乔木林、草本植物和林地枯落物对坡面径流流速和动能的影响机理.结果表明,坡面径流水头损失与坡面坡度、林木密度、净雨强、坡长等有关,水头损失与林木间距(b)和树木地径(D)间的关系为:E∝(D/b)4/3;坡面草本植物在水流作用下易弯曲,增大水流底层的阻力,减小床面的切应力;枯枝落叶使径流速度减小,从而大大降低径流挟沙能力.对甘肃省天水市桥子东沟和桥子西沟两个对比小流域的实测单次降雨、径流、泥沙资料分析可见,在相同降水条件下,已治理小流域内的径流量、产沙量、洪峰流量、最大输沙率等指标均小于未治理小流域,说明林草植被在小流域中的涵养水源、保持水土的作用明显.