Evaluation And Optimization Of Carrying Capacity Of Urban Rain Water Pipeline Based On GIS And SWMM

In every city of our country,the impermeable area expands gradually in the underlying surface of the city,which leads to the obvious change of rainfall runoff when it rains in the city.The frequent occurrence of urban waterlogging caused by rainfall is closely related to the mismatch between urban development and the capacity of urban Rain Water pipe network,and the lack of experience in the management of Rain Water in urban areas.At present,the pipeline carrying capacity of the major cities in China is becoming more and more obvious,so it is very necessary to study the bearing capacity of urban Rain Water pipe network.Through the analysis and research of Rain Water pipeline network bearing capacity,a series of optimization measures are taken,and a series of optimization measures are taken.Reduce Rain Water pipe network conformity,ensure the good operation of Rain Water system in the city.In order to study the bearing capacity and overflow point of urban regional pipe network,the GIS technology and SWMM model are used to simulate and study the rainfall runoff in different situations in some areas of a city by means of the combination of current investigation method and simulation,in order to study the bearing capacity and overflow point of urban regional pipe network.The SWMM model is constructed for analysis,and the mathematical evaluation model is established to optimize the pipe network according to the results.The main contents are as follows:(1)The evaluation model of Rain Water pipe network carrying capacity is established based on GIS technology and SWMM model,and the evaluation and optimization method of urban Rain Water pipeline network bearing capacity is put forward,and the construction method of Rain Water pipe network rainfall-runoff model is expounded.Using the software to analyze the current situation data,this paper draws the outline map of Rain Water pipe network,land use type map,summarizes the reasons of pipeline overload: the current general design standard of pipeline is lower,the crosssectional area of overflow node is less,and the cross-sectional area of overflow node is less than that of common pipeline design standard.The drainage capacity of water is poor,the proportion of permeable area is low,so when it rains,the water on the road cannot be discharged into the sewer pipe in time.(2)Put forward the evaluation criterion of Rain Water pipe network carrying capacity through the analysis of the simulation results,combined with the existing theoretical basis,established the Rain Water pipeline network carrying capacity evaluation mathematical model by the combination of entropy method and comprehensive index method.Carry on the judgment to the carrying capacity of Rain Water pipe network in the research area of a certain city.(3)The optimization method of Rain Water pipe network carrying capacity is improved.The result of Rain Water pipe network carrying capacity is the waterlogging of road surface and urban waterlogging.Therefore,according to the simulation results,this paper puts forward an optimization method to improve the bearing capacity of the urban Rain Water pipe network,and then on the basis of the two methods that have been widely used to change the elevation of the joint and the diameter of the pipe,The optimization method by changing the layout of Rain Water mouth is put forward.The results show that it is feasible to optimize by changing the layout of Rain Water mouth or adding rain nozzle.In this paper,the bearing capacity of urban Rain Water pipe network is evaluated and optimized by establishing the evaluation model of bearing capacity.According to the results of case simulation,it is concluded that the overall bearing capacity of Rain Water pipe network in this simulation area is still acceptable,and the bearing capacity of individual joints and pipe segments is large.According to the optimization results,the optimization method of increasing rain nozzle is feasible,and the three optimization methods play a significant role in improving the bearing capacity of Rain Water pipe network.