不同空间布局对城市降雨径流的影响

目的]探讨不同城市空间布局(包括分析绿地、建筑)分别到出水口不同水流长度、面积比等因素与降雨径流的关系,以优化城市典型下垫面的空间布局,实现城市雨水径流的控制。方法]以漯河市中心城区为研究对象,基于2016年3月航拍影像,提取中心城区的土地覆被信息,利用SWMM模型分析研究区在不同降雨重现期的径流特征以及影响降雨径流的因素,并定量研究城市绿地、建筑不同空间分布格局对径流削减的影响。结果]绿地、建筑面积比与径流系数呈极显著负相关,二者到出水口的水流长度对产流效应有较显著影响,绿地较建筑离出水口近的子汇水区径流系数较小,其中重现期为5a时,径流削减率最高可达到44.49%。结论]结合水流长度、面积比等因素,合理安排绿地、建筑的规模及布局,可实现雨水空间再分配,从而达到削减径流的目的。

Influence of Spatial Layout on Urban Rainfall Runoff

Objective] The objective of this thesis was to explore the spatial distribution of different cities and analyze how layout indexes, such as water flow length, and area ratio of both green space and buildings affect the runoff outlets. It was for the purpose of optimizing the spatial layout of urban typical bottom cushion and realizing the control of urban rainwater runoff.Methods] Taking the central zone of Luohe City as the research object, based on the aerial image in March 2016, extracted the land cover information of the central urban area, and used the SWMM to analyze the runoff characteristics in different rainfall recurrence periods and to extract the factors affecting the rainfall runoff. At the same time, the influences of urban buildings and green spaces to runoff reduction and layout were also studied.Results] There was a significantly negative correlation between the runoff coefficient and the values of green space and the construction area ratio. Additionally, the flow length of the water outlet had a significant effect on the runoff effect. The runoff coefficient of subcatchment was smaller which green space near the outlet was smaller than buildings, and it was found that the rate of runoff reduction got up to 44.49% when the recurrence period was 5 a.Conclusion] Through reasonable arrangement of scale and layout of green space and construction in combination with factors as water flow length and area ratio, rainwater space redistribution can be realized, runoff reduction can be achieved.