基于MIKE URBAN的城市内涝模型应用

Application of MIKE URBAN-based urban waterlogging model

针对日益突出的城市内涝问题,为了减少内涝灾害的发生、达到防洪排涝的目的,以成都市某小区为例,基于对小区排水管网的概化处理,雨量分配利用芝加哥雨型,应用MIKE URBAN软件模拟小区排水管网在不同降雨强度下承压运行情况及管点溢流情况,并通过设置小型调蓄池和扩增管径两种途径改善城市内涝状况。结果表明:改造后管网设计重现期由2年一遇提高到10年一遇,管段承压状况得到明显改善。在遭遇10年一遇降雨时,管道峰值流量明显降低,典型管道削峰率达62. 5%,管网过水能力大幅度增加。在今后排水系统改造中,应当使城市管网与雨水调蓄池等海绵措施相结合,实现削减峰值雨量,从源头上防止内涝的发生。该模型具有建模简单、运算精确的特点,对城市防洪排涝相关研究有较好的借鉴意义。

In order to decrease the occurrence of waterlogging disaster and get the target of flood control and drainage for the increasingly prominent problem of urban waterlogging,a residence community in Chengdu is taken as the study case herein,and then the conditions of pressure-bearing operation condition and pipe-point overflow of the drainage pipelinenetwork in the community under different rainfall intensities are simulated with the software of Mike Urban on the basis of generalizing the drainage pipeline network and taking Chicago rainstorm pattern for the rainfall distribution,while the status of urban waterlogging is improved by means of two methods,i.e.arranging small-sized rainwater retentionpools and enlarging pipeline diameter.The result shows that the design recurrence interval of the pipeline network is increased from the return-period of 2 years to the return-period of 10 years after the improvement,thus the pressure-bearing status of the pipeline is significantly improved.In the event of the rainfall with the return-period of 10 years,the peak discharge in the pipeline is obviously decreased with the peak-clipping rate up to 62.5%and large increase of the discharge capacity of the pipeline network.Moreover,it is proposed that it is necessary to combine the urban pipeline network with the sponge measures,such as rainwater retentionpool,etc.,to realize the peak-clipping of rainfall and prevent the occurrence waterlogging from its source.The study result has the features of simple modeling and precise operation,and then has better referential significance for the relevant study.