【摘要】 以秦淮河流域外秦淮河（凤台桥—三汊河口断面）8.5 km河段流域为研究对象，选取典型城镇溢流排口，通过实地监测及多尺度水量水质模型耦合，定量剖析城市排水系统雨天溢流污染特性及对城市受纳水体的影响机制。降雨期间，溢流口溢流污染物浓度均随降雨过程呈先上升后下降的趋势。受纳水体由于其所处位置及沿线排口分布不同表现出水质差异，在相同降雨工况下，内秦淮河作为溢流排口的直接受纳水体，其污染影响程度较外秦淮河更为严重，污染峰值更高，响应速度更快。单场次小雨引发的溢流污染负荷较低，但由于其降雨频次较高，因此全年累计溢流污染负荷最大。多尺度耦合模型显示，大雨引发的溢流污染强度最高，暴雨、中雨、小雨次之。外秦淮河因溢流出现部分断面水质超标，但由于其水环境容量较大，水质恢复较快。更多还原

【Abstract】 This study focuses on an 8.5 km stretch of the Outer Qinhuai River(from Fengtai Bridge to Sancha River Estuary) within the Qinhuai River Basin. By selecting typical urban combined sewer overflow(CSO) outlets and integrating field monitoring with a multi?scale water quantity-quality coupled model, the research quantitatively analyzes the pollution characteristics of wet?weather overflow in urban drainage systems and its impact mechanisms on receiving water bodies. During rainfall events, the concentration of pollutants from overflow outlets initially increased and then decreased as the rainfall progressed. The receiving water bodies exhibited varying water quality characteristics due to their locations and the distribution of outfalls along the river. Under identical rainfall conditions, the Inner Qinhuai River, as the direct receiving water body for overflow outlets, experienced more severe pollution impacts compared to the Outer Qinhuai River, with higher peak pollution levels and a faster response time.Although single light rain events generated relatively low overflow pollution loads, their high frequency resulted in the largest annual cumulative pollution load. The multi?scale coupled model indicated that heavy rain events caused the highest overflow pollution intensity, followed by storm rain, moderate rain, and light rain. Water quality in some sections of the Outer Qinhuai River exceeded standards due to overflow, but its larger environmental capacity allowed for quicker recovery.更多还原