海绵城市年径流总量控制率等指标应用初探

Application of Capture Ratio of Total Annual Runoff Volume in Spongy City

年径流总量控制率是《海绵城市建设技术指南——低影响开发雨水系统构建(试行)》中提出的核心指标,表征了场地中全年降雨的渗透、集蓄、利用、蒸发、蒸腾等作用控制的降雨体积,与传统的雨量、流量径流系数既有差异又有联系。从2015年海绵城市建设试点城市申报情况来看,各地同等年径流总量控制率提出的径流系数指标差异较大,客观影响指标的合理性和目标可达性。为此,采用SWMM模型,分析达到年径流总量控制率的建筑与小区类低影响开发示范项目在各种降雨条件下的雨量径流系数,从而探讨其与年径流总量控制率之间的内在联系,旨在为其他城市结合本地条件开展类似研究提供参考。

The capture ratio of total annual runoff volume is the key target proposed in the Sponge City Development Technical Guide： Low Impact Development. It represents the hydrologic effects of annual rainfall infiltration, storage, utilization, evaporation and transpiration on site. There is inherent relationship among the annual runoff volume capture, volumetric runoff coefficient and flow runoff coefficient. According to the application of the sponge city pilot project in 2015, it was significantly different among the runoff coefficients proposed by some cities in the same annual runoff volume capture. It would influence the reasonability and feasibility of the target. SWMM model was used to analyze the volumetric runoff coefficient under different rainfall conditions in building and community demonstration projects. Meanwhile, the inherent relationship between the annual runoff volume capture and the volumetric runoff coefficient was discussed. The research results would provide reference for other cities which would carry out similar studies.