城市内涝频发，管道沉积物随雨天溢流排放严重污染受纳水体。“灰-绿”设施结合作为有效解决此问题的手段已引起国内外高度关注。然而，对于土地资源紧张、污水混接严重的高密度城区分流制雨水系统，基于斑块化低影响开发（Low Impact Development，LID）与灰色设施空间耦合优化的溢流污染协同调控机制研究十分薄弱。本研究通过揭示多因素变化驱动下排水系统雨天溢流污染多源定量分配机制，建立基于累积冲刷机制的管网沉积物归趋模型，改进分布式降雨溢流污染模型，实现雨天溢流污染过程精准模拟；识别平原河网城市对降雨径流及污染变化响应敏感的LID关键参数，基于“可利用土地-径流路径-积水点”和“分散调蓄-泵排运行”研究斑块化LID和灰色设施的空间耦合与集成优化，明晰其在多因素影响下对雨天溢流污染过程的协同调控机制，有助于解决海绵城市建设的关键科学问题，对雨天溢流污染控制具有重要科学意义和应用价值。

Urban flooding occurs frequently and the sewer sediments transported by wet weather discharge to the receiving water body and seriously polluted the water environment. The combination of grey-green infrastructure as an effective means to solve this problem has attracted great attention at home and abroad. However, for storm drainages inappropriately connected with sewage in high-density urban with scarce available land resources, the research on the coordinated regulation mechanism of urban wet weather discharge pollution based on spatial coupling optimization of LID （Low Impact Development）patches and grey infrastructure is weak. In this study, by revealing the multi-source quantitative allocation mechanism of wet weather discharge pollution in storm drainages driven by multi-factor changes, the regression model of sewer sediment based on the mechanism of cumulative and erosion will be established, and the distributed model on discharge pollution in wet weather will be improved so as to realize the precise simulation. By identifying the key parameters of low impact development (LID) which are sensitive to the changes of runoff and non-point source pollution in the plain river network cities, the spatial coupling and integrated optimization of the system of LID patches and gray infrastructure will be studied based on ‘available land-runoff path-ponding point’ and ‘decentralized storage-pump drainage operation’ to clarify their coordinated regulation and control mechanism for discharge pollution in wet weather under the influence of multiple factors. This study is helpful to solve the key scientific problems in the construction of sponge city construction in high-density urban, and has important scientific significance and application value for pollution control of urban wet weather discharge.