植草沟曼宁粗糙系数变化特征及影响因素  

Changing characteristics and influencing factors of Manning's roughness coefficient along grass swales

作　　者：王建龙[1,2] 孙铮[1] 夏旭 王文海 吴学蕾 WANG Jianlong;SUN Zheng;XIA Xu;WANG Wenhai;WU Xuelei(Key Laboratory of Urban Stormwater System and Water Environment of Ministry of Education,Beijing University of Civil Engineering and Architecture;Provincial and Ministry Collaboration Innovation Center of Beijing Energy Conservation&Sustainable Urban and Rural Development,Beijing University of Civil Engineering and Architecture;CCDI(Suzhou)Exploration&Design Consultant Co.,Ltd.;Beijing Institute of Architectural Design)

机构地区：[1]城市雨水系统与水环境教育部重点实验室,北京建筑大学 [2]北京节能减排与城乡可持续发展省部共建协同创新中心,北京建筑大学 [3]悉地(苏州)勘察设计顾问有限公司 [4]北京市建筑设计研究院有限公司

出　　处：《环境工程技术学报》2023年第4期1395-1403,共9页Journal of Environmental Engineering Technology

基　　金：国家重点研发计划项目(2021YFC3001402)。

摘　　要：随着海绵城市的快速发展,植草沟得到了广泛应用。目前关于植草沟沿程流量的计算一般采用谢才公式,但其适用条件与植草沟存在显著差异,导致计算结果存在一定误差,其中曼宁粗糙系数变化是引起误差的原因之一。在假定谢才公式适用的前提下,通过足尺试验,系统研究了恒定流量、变流量进水条件下植草沟曼宁粗糙系数的变化特征,并进一步分析了植被高度对曼宁粗糙系数的影响。结果表明:植草沟沿程流量以及曼宁粗糙系数均随流动距离增加而降低;不同进水流量条件下,曼宁粗糙系数与进水流量密切相关,随进水流量增加而增加,试验条件下其最大值为0.22;另外,在植草沟不同植被高度以及不同变流量进水条件下,曼宁粗糙系数在峰值流量时刻的变化范围为0.19~0.22,试验条件下植被高度对曼宁粗糙系数影响较小。因此,植草沟的曼宁粗糙系数受沿程流量的影响较大,研究成果可以为植草沟沿程流量计算时曼宁粗糙系数的精确取值提供参考。With the rapid development of sponge cities,grass swales have been widely used.Recently,the Chezy formula is generally used to calculate the flow rate along the grass swales.There are differences between the application conditions of the Chezy formula and grass swales,which often cause remarkable calculation errors.One of the reasons for the errors is the Manning roughness coefficient variation.Assuming that the Chezy formula was appropriate,the variation characteristics of the Manning roughness coefficient of grass swales under different constant and variable inflow conditions were systematically researched through full-scale experiments,and the effect of vegetation height on the Manning roughness coefficient was further analyzed.The results showed that the flow rate and Manning roughness coefficient decreased with the increase of flow distance along the grass swale.Under different inflow conditions,the Manning roughness coefficient was closely related to the inflow rate,and the higher the flow rate,the greater the Manning roughness coefficient,with the maximum value being 0.22.In addition,the maximum Manning roughness coefficient of grass swale with different vegetation heights was 0.19-0.22 under different variable flow inflow conditions,and the vegetation height had little influence on the Manning roughness coefficient under the experimental conditions.Therefore,the Manning roughness coefficient of grass swale was markedly affected by runoff volume.The research results can provide reference for selecting the Manning roughness coefficient in the calculation of grass swale drainage capacity.

关 键 词：植草沟 谢才公式 曼宁粗糙系数 雨水径流 水力特性 

分 类 号：X703[环境科学与工程—环境工程]