基于SWMM的城市排水系统改造优化研究

为了解决城市排水系统改造优化时系统淤积的问题,采用SWMM(Storm Water Management Model)模拟技术进行排水系统改造优化研究。以柳州中心城区为例,构建包含淤积设置的排水系统现状模型进行现状评估,并构建清淤工况模型来评估清淤措施的效果。在清淤模型基础上,针对p=5年情景分析系统溢流原因并进行改造,将过水能力不足的管段增加断面尺寸,使得系统能够抵御5年一遇降雨,并运用模型验证其可行性。结果表明:现状排水系统在p=2年情景下溢流量为9 083 m3,排水能力较弱,其原因是设计标准较低且存在一定的淤积现象;将系统进行清淤措施后在p=2年情景下溢流量为2 616 m~3,减少了71.2%,有明显改善但还存在较大的溢流现象;以5年一遇为目标对系统15%的管段进行改造,改造后在p=2年、p=3年情景下均无溢流现象,在p=5年下溢流量为238 m~3,不足以形成内涝灾害。改造方案可以有效地解决城市内涝现象,并为城市排水系统改造优化提供参考依据。

Study on reformation and optimization of urban drainage system based on SWMM

In order to solve the problem of sediment deposition in urban drainage system optimization，using the SWMM （Storm Water Management Model） simulation technology to optimize the drainage system. Take the central city of Liuzhou as an example，building the status model of drainage system with sedimentation for status evaluation，and the dredging condition model to assess the effect of dredging measures. Based on the dredging model，analyzing the reasons of overflow in p=5a and put forward the reform scheme accordingly. By means of increasing pipeline cross section size，the drainage system can resist the rainfall with the return period of 5 years. The model test has verified the feasibility. The result shows that the drainage capacity of the present drainage system is weak while the overflow discharge is only 9 083 m3 in p=2a. The reason is that the design standards are low and there is a certain sediment deposition phenomenon. After the system has been dredged，the overflow discharge is 2 616 m3 in p=2a，reduced by 71.2%，which has obviously improved but there is still a certain overflow phenomenon. After the reformation of almost 15% pipelines，there is no overflow in p=2a and p=3a，and the overflow discharge is 238 m3 in p=5a，which is not enough to form waterlogging disaster. Therefore，the reform scheme can solve the problem of waterlogging in cities and provide a reference for the optimization of the urban drainage system.