| 摘要: |
| 城市下垫面类型的多样化,使得径流系数在时空上的变化越来越复杂。采用自制模拟降雨系统,对SBS、不透水地砖、水泥地面、透水砖和草地等典型下垫面进行了实验研究。结果表明:弱透水性的下垫面径流系数容易达到较高的稳定值,透水砖的下渗能力接近草地。双曲线模型能够较准确地描述径流系数与单影响因素之间的关系,并得了到具有一定物理意义的降雨历时(或雨强)与各下垫面径流系数的最优拟合公式,且除透水砖外其相关系数达92%~97%,可见降雨历时对径流系数的影响较大。相同降雨条件下,3种弱透水性下垫面按径流系数由大到小依次为:不透水砖、SBS、水泥路面。降雨量较小时,下垫面的表面洼蓄及附着水层的比例不能忽略,此时径流系数不能反映渗透能力。透水砖和草地的下渗能力很强,适当增加其面积可提高城市雨水下渗能力。本研究可为城市雨水利用研究的后续工作提供参考。 |
| 关键词: 雨水利用,径流系数,降雨强度,下垫面 |
| DOI：10.11841/j.issn.1007-4333.2006.05.125 |
| 投稿时间：2006-02-28 |
| 基金项目:国家自然科学基金资助项目(4027102250279041)，陕西省水资源与环境重点实验室基金项目 |
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| Experimental study on relationship among runoff coefficients of different underlying surfaces, rainfall intensity and duration |
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| Abstract: |
| The change of runoff coefficient in the time and space has become more and more complicated because of the diversification of the underlying surface of a city.The experiments for 5 typical underlying surfaces were carried out,that is,SBS,waterproof brick,cement road surface,permeable brick and grassplot by the artificial rainfall simulation system.The results show that the runoff coefficient is easier to reach a steady value for a poor infiltrate surface.The permeability of a permeable brick is close to a grassplot.Hyperbolic models had a higher precision to describe the relationship between runoff coefficient and single influence factor.The optimized simulation formulae of rainfall duration and runoff coefficient with certain physical significance were obtained.The rainfall duration has a significant effect on runoff coefficient and its correlation coefficient is as high as 92%-97% except for a permeable brick.Under the same condition of rainfall,the order of runoff coefficient of three poor infiltrate surfaces is waterproof brick,SBS and cement road surface in sequence.The proportion of low-lying detention and coherence water layer couldn't be neglected with a small rainfall and the permeability couldn't be reflected by runoff coefficient.The infiltration capacity of underlying surface in a city will be improved with the increase of the proportion of permeable brick and grassplot expanded. |
| Key words: rainwater utilization,runoff coefficient,rainfall intensity,underlying surface |
