基于水文控制目标的中小尺度海绵城市改造方案评价

Evaluation of reconstruction schemes for small-and medium-scale sponge city based on hydrological control target

为正确评价中小尺度低影响开发(LID)措施改造方案的水文控制效能,以重庆市秀山县海绵城市建设试点为例,将LID措施的生态、经济和社会效应具体量化为径流量控制、径流污染控制、建设成本、维护管理成本和径流利用效益等5个指标,构建了基于水文控制目标的LID措施评价体系,并利用暴雨管理模型(SWMM)对不同LID设施改造方案的暴雨径流水文过程进行了验证模拟。研究结果表明:现有LID措施因其规模占比过小且组合方式不合理而对暴雨径流的水文控制效果不佳,不满足75%年径流总量控制率目标,需进行扩容和组合优化;LID设施改造方案综合评价结果显示综合评分与径流总量控制率、峰值流量削减率等水文控制指标呈显著正相关,可直接作为中小尺度海绵城市改造方案评价。

In order to correctly evaluate the hydrological control effectiveness of small-and medium-scale low impact development(LID) reconstruction schemes, taking the construction pilot of Xiushan sponge city in Chongqing as an example, the ecological, economic and social effects of LID measures are specifically quantified into five indicators, i.e. runoff control, runoff pollution load control, construction cost, maintenance and management cost and utilization efficiency of rainwater, and an evaluation system of LID measures based on hydrological control target was constructed, and the rainstorm runoff hydrological processes in different LID retrofitting scenarios were simulated and verified by stormwater management model(SWMM). The results show that the existing LID measures have poor hydrological control effect on Rainstorm Runoff because of their small scale and unreasonable combination. They do not meet the target of 75% annual total runoff control rate and need to be expanded and optimized. The comprehensive evaluation results of LID facilities renovation scheme show that the comprehensive score is significantly positively correlated with hydrological control indexes such as total runoff control rate and peak flow reduction rate, which can be directly used as the evaluation of small-and medium-scale sponge city renovation scheme.