成都市雨水径流污染及生态调控研究

Study on Rainwater Runoff Pollution and Ecological Regulation in Chengdu

摘要: 为探讨高密度城市建设背景下雨水径流污染特征及生态调控路径，本研究以成都市交通干道、居住小区、商业片区、工业园区和公园绿地五类典型功能区为对象，构建典型降雨事件监测方案，选取悬浮物(SS)、化学需氧量(COD)、氨氮(NH₃-N)、总氮(TN)和总磷(TP)等指标，分析不同下垫面径流污染差异、初期冲刷特征及生态设施削减效果。结果表明，交通干道和工业园区径流污染负荷相对较高，公园绿地污染水平较低；五类功能区SS事件平均浓度(EMC)范围为64~182 mg/L，COD的EMC范围为31~86 mg/L；前30%径流量对SS和COD污染负荷贡献分别为42%~61%和38%~55%，说明初期雨水是面源污染控制的重点时段。生物滞留设施和调蓄湿地对SS、COD和TP具有较好的削减潜力。基于此，提出“源头减排–过程滞蓄–末端净化–智慧管控”的城市雨水生态调控策略，以期为成都市海绵城市建设和城市水生态安全维护提供参考。

Abstract: To investigate characteristics of rainwater runoff pollution and ecological regulation path under high-density urban development, this study selected five typical urban functional areas in Chengdu, including traffic roads, residential communities, commercial districts, industrial parks and urban green spaces. A typical rainfall-event monitoring scheme was designed, and suspended solids (SS), chemical oxygen demand (COD), ammonia nitrogen (NH₃-N), total nitrogen (TN) and total phosphorus (TP) were selected as key indicators to analyze pollution differences among underlying surfaces, first flush characteristics and removal effects of ecological facilities. The results showed that traffic roads and industrial parks had relatively higher runoff pollution loads, while park green spaces had lower pollution levels. The event mean concentrations of SS and COD ranged from 64 to 182 mg/L and from 31 to 86 mg/L, respectively. The first 30% of runoff contributed 42%~61% of SS loads and 38%~55% of COD loads, indicating that initial runoff should be regarded as the key stage of non-point source pollution control. Bioretention facilities and detention wetlands showed good removal potential for SS, COD and TP. A regulation strategy integrating source reduction, process retention, terminal purification and intelligent management is proposed to support sponge city construction and urban water ecological security in Chengdu.