Simulation Study On The Optimization Of Scheduling Strategy Of Complex Urban Drainage System Based On Dynamic Control

Urban flooding and overflow pollution are natural disasters with high frequency in cities.However,with the accelerated urbanization process,the agglomeration effect of urban residential population is becoming more and more obvious,resulting in the increasing risk of disaster losses.At present,because the influence of global climate change,extreme rainstorms occur frequently in cities,the control of urban flooding and overflow pollution has become a research hotspots.In recent years,the development of real-time online monitoring technology,big data cloud technology and numerical computing technology has become more and more mature,which provides new methods and approaches to explore the problems of urban flooding and overflow pollution.Scholars at domestic and abroad have done massive work in above aspects.Based on the in-depth analysis of previous study.this paper constructs the urban drainage on-line monitoring system by using the research method of the combination of on-site monitoring and model simulation.In addition,the dynamic dispatching control strategy of urban drainage system is studied based on hydraulic model simulation,and the fuzzy identification method of rain pattern is further explored,in order to provide theoretical and technical basis for the dynamic dispatching control of urban drainage system.Some valuable conclusions obtained in this study are as follows.(1)Based on the in-depth analysis of the urban drainage online monitoring system studied by predecessors and the purpose of dispatching control,This paper constructes an ultraviolet-visible spectrophotometric(UV method)online water quality monitoring system.After a long-term test,the results show that the online water quality monitoring system built in this paper is stable in operation,highly accurate,and it can well reflect the changes in water quality at the monitoring points of the drainage network.Among20 groups of comparison experimental results,85% of the data deviation is≤ 15 mg /L,which meets the auxiliary scheduling decision engineering application requirements.Meanwhile,the online water level and water quality monitoring system is further coupled at the data layer level by editing the logical strategy relationship with different response speeds.The theoretical analysis shows that the coupling system can ensure that the subsystem avoid suffering from waterlogging and overflow pollution,save more pipe and canal transfer space for other drainage regulation subregions in the downstream basin,and contribute to the realization of scientific joint regulation of the whole basin.(2)Infoworks ICM was used to build a hydraulic model and simulate the dynamic scheduling strategy for the study area.The dynamic scheduling strategy under 16 design rainfall scenarios in the study area is simulated and the real-time control strategy logic diagram is drawn.Based on the simulation results of the optimal scheduling strategy under different design rainfall scenarios,the response of urban drainage scheduling effect to different rainfall rainfall patterns and scheduling strategy change steps is analyzed to reveal its inner connection.The results show that the overflow phenomenon of the design rainfall of R0.2 is significantly more serious than that of R0.4 under the same design rainfall scenario,and the total relative pump running time of the design rainfall of R0.2 is all larger than that of the design rainfall of R0.4.In addition,under the design rainfall scenario of R0.4,the overflow pollution can not be significantly improved by adjusting the strategy water level step.Therefore,it can be concluded that the rainfall rain pattern has a significant effect on the urban drainage scheduling effect,while the change of scheduling strategy has no significant effect on the urban drainage scheduling effect.(3)Based on the in-depth analysis of previous research on rainfall classification and rainfall identification methods,a dynamic rainfall fuzzy identification method is proposed.The standardized Euclidean distance is used to describe the similarity of the rainfall process,and the similarity method is used to characterize the accuracy of the rainfall fuzzy identification method.Two rainfall peak coefficients of 0.2 and 0.5 are randomly selected for comparison and analysis tests between the actual rainfall and the strategic rainfall in short calendar periods.It can be seen that the results of both rain pattern fuzzy identification are close to the same with the actual rainfall in terms of peak coefficient and cumulative total rainfall index,the results meet the requirements,which can provide theoretical and technical reference for realizing the dynamic scheduling control of drainage system.In addition,the research results reveal that the error of rain pattern fuzzy identification can be relatively large during the similar time period of the actual rainfall peak location.When applying this identification method for dynamic scheduling control,it is necessary to be alert to the flooding risk control during the peak period.