Simulation And Evaluation Of Sponge City Facility Design In A Hospital In Changsha

This project draw on the experiences of advanced concepts and practical experience at domestic and abroad,taking the hospital in Changsha as the research area.By studying available information and field survey and using SWMM model(StormWater Management Model)to study regional modeling,design and simulation to evaluate the effectiveness of sponge urban facilities.Firstly,combining the data of the nature of land use planning,vertical elevation,and rainwater pipe network in the region,the watershed division and the generalization of the rainwater pipe network were carried out.SWMM simulation software was used to initially build a rainwater pipe network in a hospital in Changsha City.secondly,the original diameter of the rainwater pipe and the elevation of the pipe bottom elevation were checked and redesigned;thirdly,the LID facility was selected,the scale of the LID facility was determined through SWMM simulation,and the LID facility was guided through the analysis of the water accumulation in the study area.The layout of the study was finalized and summarized,and the total runoff control rate,runoff peak reduction effect,and time delay of peak flow rate as well as runoff pollution control effects of the research program under different return periods were analyzed.The simulation results of the model show that the scale of sponge city facilities to be built in a hospital in Changsha City is 3318m2 for rainwater gardens,6732m2 for sunken green spaces,11250m2 for permeable pavers,10753m2 for green roofs,and 240m3 for storage facilities.The sponge facilities can effectively reduce total runoff.Volume and peak flow,and can significantly reduce the load of rainwater drainage pipe network and delay the time of occurrence of runoff peak;Sponge has a significant effect on the reduction of peak rainfall flow during the small return period;the simulation reaches the annual runoff total rate control rate of 75.78%and the peak rate of runoff reduction and postponement and the annual runoff pollution control rate were 71%.This study has improved the simulation and design of the sponge city.The results of the study are of great significance for alleviating the stormwater management problems caused by urbanization in China.