Smart Sponge City Waterlogging Simulation And Early Warning System Study

In recent years,the rapid development of domestic urbanization,traditional construction has changed the city’s original hydrological pattern,water ecology,water environment,water safety and other aspects of frequent problems,including stagnant waterlogging is increasingly prominent,in order to effectively alleviate and gradually solve the urban rain and flooding problems,combined with our national conditions and foreign low impact development(LID)concept,proposed the construction of "sponge" city long-term development strategy.In this paper,the Xiushan county-level sponge city pilot renovation area is taken as the study area,and the real-time rainfall and site water level data transmitted from the new rainfall monitoring station to the smart sponge platform are selected as the basis,using the Storm Water Management Model(SWMM)and the Urban Pipe Network System Model(DHI MIKE URBAN)to simulate rainfall in the study area under different recurrence periods,and to conduct waterlogging analysis and risk-based warning and propose corresponding flood prevention measures.(1)SWMM and MIKE URBAN model construction,sensitivity analysis and calibration of unspecified parameters.(2)To study the rainfall simulation of the SWMM model under three conditions with or without evapotranspiration data to illustrate the influence of evapotranspiration data on the operational accuracy of SWMM.(3)MIKE URBAN model rainfall simulation.(4)Optimal rainfall simulation results of the two models are selected for internal waterlogging analysis,and the risk of actual internal waterlogging in the study area is warned.The main findings of this paper are as follows.(1)Identify the study area according to the actual basic data and build the corresponding model,with a total of 2161 nodes and pipes.2126 roots and 396sub-catchment areas.(2)Both SWMM and MIKE URBAN contain unspecified parameter sensitivities that vary with rainfall intensity.SWMM total runoff is the sensitive source.Analysis,minimum/maximum infiltration rate(Min/Max-R),and attenuation coefficient(D-C)are the most sensitive.Total Flood Peak is analyzed as a sensitive source,with the greatest sensitivity for pipeline roughness coefficient(C-R)and impervious zone roughness coefficient(N-i).MIKE URBAN was analyzed for total runoff volume as a sensitive source,with the greatest sensitivity to initial rainfall loss(L-i),and attenuation coefficient(R-f)..The total number of flood peaks is the most sensitive source for the analysis,with R-f and pipeline Manning coefficient(M-n)being the most important and determinant of the sensitivity.The parameters of the role.(3)Calibrate the sensitivity analysis parameters to increase the applicability and reliability of each model.Determine the unknown parameters of SWMM N-i is 0.03,N-p is 0.3,D-i is 5 mm,D-p is 15 mm.76 mm/h for Max-R,10 mm/h for MIn-R,4h-1for D-C,4h-1 for C-R.0.011;determine that the MIKE URBAN unknown parameters L-i is 0.004 m,R-f is 0.4,T-c is the model auto-calculated value,M-n is 60.(4)MIKE URBAN applicability with and without evaporation data for SWMM runs with large variation in results and large scale area modeling Better than SWMM,with a maximum runoff control rate of 41.5% for SWMM Case 1(regardless of evaporation),and a maximum runoff control rate of 41.5% for Cases 2 and 3(regardless of evaporation).(taking evaporation into account)runoff control of up to 69.2%;MIKE URBAN runoff control after running simulations of up to 75.7%.(5)Conduct waterlogging analysis by node overflow and pipeline overload.The overflow water level h is graded,and the smallest proportion of serious overflow point to total overflow node is 2.27% at 1a,and the smallest proportion of serious overflow point to total overflow node is 2.27% at 20 a.Maximum of 9.33%,with the maximum number of increases at 5a-10 a,5.The pipeline filling level a is graded.The proportion of severely overloaded pipes to total overloaded pipes is only 0.79% at 1a,2.29% at 10 a,and 2a-10 a.Maximum number added at 5a,7 articles.(6)Based on the model in 50 a the risk of flooding in the study area is low.The runoff control rate analysis showed that 72.09 mm of stormwater runoff was reduced at50a;the total overflow analysis showed that its The depth of overflow is 5.24mm;water analysis of road area,when the node overflows to the pavement diffuses 1m,the maximum road area water at 50 a The depth is 28 mm;the overloaded pipe analysis has a maximum pipe fill of 8.818 at 50 a.