由于气候变化和城市化加剧,近年来我国洪涝灾害频发,雨季内涝问题十分严重。通过布设低影响开发(LID)设施能够有效应对这类城市内涝问题。目前,进行低影响开发设施量化布局的研究较少。通过对年径流总量控制率的分解提出了系统的LID规模量化布局的方法,以太原市迎泽街道为例,运用雨洪管理模型(SWMM)开展系统性分析。以太原市年径流总量控制率80%为目标,选用透水铺装、雨水花园和绿色屋顶3种LID设施进行布局。经计算,LID总调蓄容积设计满足年径流总量控制率目标。在 1 、5 、10 a 一遇短历时设计降雨情景下,排放口径流量显著降低,排放口O1、O2、O3 和O4 的最大径流量控制率分别达到了82.30%、84.93%、81.43%和87.55%;该地区最大峰值径流量分别降低了66.73%、65.5%和43.7%,且有效延迟了峰值出现时间;此外,LID设施提高了场地对雨水的渗透、滞蓄和控制能力,降低了管网充满度,减少了溢流节点个数,减轻了管网排水压力,减少了溢流污染的风险。研究成果为迎泽街道及类似城区的海绵城市建设提供了科学的理论依据与实践参考,同时也为未来城市雨洪管理工作的持续优化指明了方向。

[Objective] Due to climate change and accelerated urbanization, flood disasters have occurred frequently in China in recent years, and urban waterlogging during the rainy season has become a severe problem. The deployment of Low Impact Development (LID) facilities can effectively address such urban waterlogging issues. At present, there are relatively few studies on the quantitative layout of low-impact development facilities. [Methods] This paper proposes a systematic method for the quantitative layout of LID facilities by decomposing the annual runoff volume capture ratio. Taking Yingze Subdistrict of Taiyuan as an example, a systematic analysis is carried out using the Storm Water Management Model (SWMM). With the annual runoff volume capture ratio of 80% in Taiyuan as the target, three types of LID facilities—permeable pavement, rain gardens, and green roofs—are selected for the layout. [Results] According to the calculations, the designed total storage volume of LID facilities meets the target of the annual runoff volume capture ratio. Under the design rainfall scenarios of 1-year, 5-year, and 10-year return periods with short durations, the runoff at the outfalls is significantly reduced. The maximum runoff capture ratios of outfalls O1, O2, O3, and O4 reach 82.30%, 84.93%, 81.43%, and 87.55%, respectively. The maximum peak runoff in the area is reduced by 66.73%, 65.5%, and 43.7%, respectively, and the peak occurrence time is effectively delayed. In addition, LID facilities improve the site’s ability to infiltrate, retain, and control rainwater, reduce the pipe network fullness ratio, decrease the number of overflow nodes, alleviate the drainage pressure of the pipe network, and lower the risk of overflow pollution. [Conclusions] The LID facility layout scheme proposed in this study has a significant effect on alleviating the rainwater and flooding problems in the study area, and can provide a scientific theoretical basis and practical reference for the construction of sponge cities in regions with local low-lying terrain, high building density and a large proportion of impervious area.