水保所知识产出(1956---)知识库

黄土区草被覆盖下的坡面水流流速特征研究对于深刻认识该区草地坡面侵蚀动力和科学决策该区水土保持与生态建设具
有重要意义。采用草地小区人工模拟降雨试验方法，对黄土区草地坡面水流流速随雨强及坡度的变化特征进行研究，结果表明:
①在5 个不同雨强及 5 个不同坡度下，草地坡面流速随降雨历时变化均表现为产流初期流速快速增大，持续一段时间之后转为缓慢
增大或保持稳定，且可用幂函数描述;②草地坡面次降雨产流平均流速分别随单一因子雨强、坡度的增大而增大，且皆可用对数函
数描述;③草地坡面次降雨产流平均流速随雨强及坡度复合因子的变化可用二元对数函数描述，试验条件下坡度对草地坡面水流
平均流速的影响大于雨强的影响。

 The study of flow velocity on grassland slope is of great significance to understand dynamic of erosion deeply and to make scientific
decision on soil and water conservation and ecological construction in Loess Plateau． In order to study the variation of flow velocity with rain-
fall intensity and slope on grassland slope，in the paper，we adopted artificial rainfall experiment to study flow velocity． The results show that:
a) under five different rainfall intensities and slopes，variation of flow velocities with time first increase rapidly after becoming increase slowly
or stably and relationships between them can be described by the power function equations; b) average runoff velocities on grassland slopes
increase with the increase of rainfall intensities and slopes respectively，which can be described by the logarithmic function equation; c) av-
erage velocities of grassland slope with rainfall intensities and slopes can be described by the dual logarithmic function equation and in the ex-
periment，the influence of slope on grassland average velocity is greater than the influence of rainfall intensity to the grassland
average velocity．