上海市苏州河沿岸排水系统雨洪控制研究

Urban Stormwater Control of Drainage Systems along Suzhou Creek in Central Shanghai

以苏州河环境综合整治二期工程中建设的5座大型雨水调蓄池所服务的排水系统为研究对象,探究了雨水调蓄池对排水系统的雨洪控制效益。研究显示,雨水调蓄池可有效缓解排水系统的防汛压力和减轻对苏州河的水环境污染,具体表现为:①提高现有排水系统短时截流倍数。在小雨、中雨、大雨和暴雨条件下,调蓄池对系统瞬时截流倍数的提高范围为5.6～14.8倍,对系统短时平均截流倍数的提高范围为2.2～6.8倍。②调蓄池最大可延迟8.1 m3/s流量以下的雨洪溢流时间约1.5 h。③具有削减排水系统雨洪溢流污染物的良好效益,对雨洪污染减排的效应随着容积建设标准的增大而提高。在容积建造标准介于20～105 m3/hm2的条件下,对雨洪溢流水量的削减率为5.4%～78.8%,对雨洪溢流COD的削减率为8.1%～92.3%。④改善受纳水体COD浓度的效应随着调蓄池容积建造标准的提高而增强,随着水动力的增强而降低。5座调蓄池联动使用时,在断面平均流速为0.50、0.30和0.10 m/s等三种模拟条件下,可使雨洪过程中苏州河河口断面全过程COD通量浓度分别下降13.2、13.8和14.4 mg/L。

Five stormwater detention tanks （SDTs） were built along the Suzhou Creek in central Shanghai in the two-stage Suzhou Creek comprehensive environmental treatment project. The effect of SDTs on stormwater control of drainage systems was investigated. The results showed that SDTs could effectively reduce stormwater volume in drainage systems and water pollution of Suzhou Creek：①SDTs could enlarge the short-time interception ratio of drainage systems effectively. Under light rain, moderate rain, heavy rain and rainstorm, the instant interception ratio could be enlarged by 5.6 to 14.8 times. The mean short-time interception ratio could be enlarged by 2.2 to 6.8 times. ②SDTs could delay stormwater peak by about 1.5 h with a maximum discharge 8.1 m3/s. ③ SDTs could reduce CSO pollu- tants effectively, and the reduction effect was improved with the increase of detention volume. The reduc- tion rates of overflow volume and COD were 5.4% to 78.8% and 8.1% to 92.3%, respectively, when the detention volume was 20 to 105 m3/hm2. ④ The quality improvement effect of the receiving water body was increased with the increase of detention volume, and decreased with the increase in hydrody-namic force. The COD concentration of the Suzhou Creek at estuary section could be reduced by 13.2 rag/L, 13.8 mg/L and 14.4 mg/L at flow velocities of 0.50 m/s, 0.30 m/s and 0.10 m/s when using five SDTs.