摘要
高羊茅作为我国北方典型冷季型城市草坪草,具有调蓄雨水的作用。为了进一步深入研究北方高羊茅草地的降雨径流,本文采用人工模拟降雨试验,研究了高羊茅草地在不同覆盖度(60%和90%)及不同雨强(30、60和90mm/h)条件下的径流系数变化过程及其与影响因子之间的关系,并用裸地作为对照,得出高羊茅草地在不同试验条件下的径流系数削减率。研究结果表明:1)高羊茅草地初始产流时间随雨强增加逐渐提前,随着覆盖度的增加逐渐延长,同时,雨强越大初始产流时间提前幅度越小,覆盖度越大草地延缓初始产流时间的效果越明显;2)裸地和高羊茅草地的径流系数随降雨时间变化规律相似,均随降雨时间的延长先迅速增加后逐渐变缓,经过拟合裸地及高羊茅草地的径流系数与降雨时间均呈对数关系;3)高羊茅草地地表径流系数随着覆盖度的增加而降低,随着雨强的增加而增加,且覆盖度越低雨强对径流系数的影响越显著,反之则越不显著;4)高羊茅草地对径流系数的削减能力有限,随着雨强的增加两种覆盖度草地径流系数削减率越相近,在雨强为30、60和90 mm/h时两种覆盖度草地径流系数削减率分别相差25%、24%和23%;5)建立试验条件下高羊茅草地径流系数与降雨强度、覆盖度、降雨时间的回归方程,经过验证,方程可用于试验条件下高羊茅草地径流系数的预测。
Festuca arundinacea as a kind of typical grass in northern China, it has the advantage of storing and infiltrating rain water. In order to research the runoff of F. arundinacea grassland, we studied the changing process of runoff coefficient under different coverage (bare land, 60%, 90% ) and varied rainfall intensities (30, 60, 90 mm/hour) in F. arundinacea grassland through artificial simulated rainfall experiments. And we also studied its relationship with different influencing factors. Taking bare land as control, we studied the runoff coefficient reduction rate of F. arundinacea grassland under varied experimental conditions. The results showed that: 1 ) The initial runoff time of F. arundinacea grassland decreased with the increase of rainfall intensity, and it prolonged with the increase of coverage. Simultaneously, the greater the rainfall intensity was, the smaller range the runoff coefficient reduction rate became. And the greater the coverage was, the more obvious the grassland delayed the initial runoff time. 2) The runoff coefficient of F. arundinacea grassland and bare land both rapidly increased and then tended to be stable with the increase of rainfall time. After simulation, it was found that the runoff coefficient all showed a logarithmic function with rainfall time. 3 ) Runoff coefficient of F. rundinacea grassland decreased with the increase of coverage, and it increased with the increase of rainfall intensity. Also, the lower the coverage was, the more significant the rainfall intensity affected runoff coefficient. But the larger the coverage was, the less significant the rainfall intensity affected runoff coefficient. 4) The ability of F. arundinacea grassland in reducing runoff coefficient was limited. With the increase of rainfall intensity, runoff coefficient reduction rates of two kinds of coverage grasslands were more close. When the rainfall intensities were 30, 60, 90 mm/hour, the differences in runoff coefficient reduction rate between the 60% and 90% coverage grassland were 25% , 24% , 23% , respectively. 5) The regression equation of the runoff coefficient of F. arundinacea with rainfall intensity, coverage and rainfall time was established under experimental conditions. After verification, the equation could be applied to predict the runoff coefficient of F. arundinacea grassland under the experimental conditions.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2017年第5期82-88,共7页
Journal of Beijing Forestry University
基金
国家水体污染控制与治理重大专项(2013ZX07304-001)
科技创新服务能力建设--协同创新中心--林果业生态环境功能提升协同创新中心(PXM2016_014207_000083)
关键词
人工模拟降雨
覆盖度
降雨强度
径流系数
simulating rainfall
coverage
rainfall intensity
runoff coefficient