Typical Urban Waterlogging Simulation And Sponge Reduction Control Effect Reserch Based On Infoworks ICM Model

In recent years,with the development of urbanization.the urban water cycle process had great change.This change caused frequent occurrences of extreme rainfall events,an increase in total runoff and runoff cocfficicnts,and increase risk of urban waterlogging.The problem of urban waterlogging disaster had become a prominent bottleneck restricting the China's economic and social sustainable development.Therefore,studying the urban waterlogging disaster had important significance and application value,which can provide scientific basis for disaster prevention and control.This paper took the Macao River Basin in Beijing as the research object,clollected and analyzed the previous research data.summarized the causes of urban w aterlogging disaster.Refined flood model was established based on Infoworks ICM model to simulate the waterlogging conditions of the basin.The risk of waterlotgging was assessed wth thwaterlogging assessment method.Combined with the sponge supporting measures specified in the Beijing local standard(Code for design of stormwater management and harvest Engineering(DB11/685-2013)).The sponge reduction control model was established to simulate waterlogging conditions of the basin after the modification of the sponge measures.The effect of sponge measures on urban waterlogging improvement was quantified.The main researchachievements are as follows:(1)Typical cases of waterlogging disaster research was analyzed to summary the causes of urban waterlogging disaster.The result showed that the reason for the occurrence of urban waterlogging disaster is physical geography,impact of human activity,infrastructure and management system.To analysis the research methods of waterlogging risk in typical cases and obtain a more complete risk assessment process.The first step is to determine the scope of the disaster,the second step is to establish disaster data,and the last step is the classification of risk grade.Based on the British flood management method,the land use type was revised to set a new risk assessment methods based on the risk index.And applied it to assess the risk of waterlogging in the Macao River Basin(2)The geographical overview,drainage network data,basic topographic data and hydrological data of Macao River Basin were collated and corrected.And the basic data for constructing the urban refined flood model was obtained.The refined flood model of the Macao River Basin was constructed by using Infoworks ICM model software.The model parameters were determined and verified by measured rainfalls,and a highly reliable flood model was obtained(3)This paper set up simulation scenarios based on design rains with different return periods.Through model simulation,the node overflow and water depth under different simulation scenarios are compared and analyzed.The results showed that the overflow and water accumulation are aggravated with the increase of the return period.The overflow and water accumulation are affected by the rainfall intensity and rainfall,but the rainfall has more significant impact.The main reasons affecting the waterlogging in the Macao River Basin are:the pipe network drainage capacity is low,the terrain of the watershed is low,and the impervious area in the basin is too large(accounting for 66.59%)(4)Combined with the results of the internal hemorrhoid simulation,the risk of waterlogging in the Macao River Basin was assessed using the intrinsic risk assessment method and the waterlogging risk map was drawn.The results of risk analysis showed that the waterlogging risk area is aggravated with the increase of the return period,and the expansion trend of the high-risk area is significant.Generally speaking,the high-risk areas are widely distributed compared with the medium-risk areas and low-risk areas,and they are concentrated in Neihuan West Road,Fanyang Road,Jingkai Road,etc(5)The sponge reduction measures were added to the refined flood model in the Macao River Basin,and the sponge reduction control model was established.The simulation results showed that the sponge measures can effectively control the overflow and water accumulation in the basin.The current situation is compared with the sponge modification,sponge modification can effectively control the waterlogging risk,and the effect of reducing control in low-recurrence period is significant;the effect of reducing and controlling in low-risk and medium-risk areas is better than that in high-risk areas.Which explained the reduction and control effect of sponge measures on the waterlogging risk in the Macao River Basin.