坡度对低影响开发道路水文参数的影响

INFLUENCE OF SLOPE ON HYDROLOGICAL PARAMETERS OF LOW IMPACT DEVELOPMENT ROADS

近年来,海绵城市在我国得到快速发展,其中低影响开发道路是重要建设内容之一。坡度是影响低影响开发道路雨水控制利用效果的关键因素之一,尤其是山地城市道路纵坡普遍较大,目前尚缺乏系统研究。针对上述问题,在实验室搭建了1∶1物理模型,通过人工模拟降雨实验,系统研究了坡度对低影响开发道路雨水径流总量控制率、峰值削减率、径流系数等水文参数的影响。实验结果表明:低影响开发(LID)道路场次雨水径流总量和峰值流量受坡度影响较大,其削减率分别为7.5%~73.2%和4.5%~52.6%;径流系数受重现期影响较大,在低重现期时为0.20~0.66,在大纵坡和高重现期时均接近1。LID道路在纵坡<5%和重现期<10 a时雨水径流总量和峰值削减效果较明显,在大纵坡和高重现期时雨水外排总量和峰值削减效果较差。上述研究成果可为山地城市低影响开发城市道路设计提供技术支撑。

In recent years,sponge cities developed rapidly in China,and low impact development roads were one of the important construction contents.Slope is one of the key factors affecting the effect of urban stormwater control by low impact development roads,while there is still no systematic research on the large slope of mountainous urban roads.In this paper,a 1∶1 physical model was built in the laboratory.Through artificial simulation of rainfall experiments,the effect of slope on hydrological parameters such as stormwater runoff total control rate,peak reduction rate and runoff coefficients of low impact development roads were systematically studied.The results showed that:the total amount of stormwater runoff and peak flow were affected by the slope,and the reduction rates were 7.5%~73.2%and 4.5%~52.6%,respectively.The return period had the greatest impact on runoff coefficient,which was 0.20~0.66 in the low return period and closed to 1 in both large slope and high return period.The LID road had a significant effect on the total amount of stormwater runoff and peak reduction,when the slope was 5%below and the return period was shorter than 10 years,while the effect was poor in large slope and high return period.The above research results were intended to provide technical support for the design of urban roads for low impact development in mountainous cities.