A Study On The Effect Of Sponge Renovation In The Tongjian Rose Nanyuan Community

Since the reform and opening up,China has entered a stage of rapid urbanization.A large number of urban land has been developed and constructed,destroying the natural cycle of rainwater,causing water pollution,frequent waterlogging and many other urban water problems.For this reason,China has proposed the "source Combining emission reduction,process control,and end treatment,the first batch of pilot sponge cities in the country was launched in 2015 to reduce the amount of runoff and pollutant emissions from the source.As an important part of the construction of a sponge city,building communities are difficult to transform into old buildings and evaluate the construction effect.Therefore,this article selects Wuhan Tongjian Rose Nanyuan Community as the sponge of old communities.The research object of the transformation started from the analysis of the current problems,proposed a sponge design plan,and used the Infoworks ICM model to compare and analyze the rainwater control effect before and after the sponge transformation in the research community,and formed the following main research results:(1)Through the Info Works ICM model to simulate the current rainwater control effect of the unified construction of the Rose Nanyuan Community,it is concluded that the total annual runoff control rate of the current underlying surface of the study area in2013 under the conditions of annual rainfall and evaporation is 49.2 %;Under the conditions that the design rain return periods are 1a,2a,5a,and 10 a,the water accumulation area in the community is distributed on the road of the community,and the depth of the water is 4.8cm,5cm,6.2cm,7cm,and the current drainage network The number of overflow nodes are 4,4,25,and 31 respectively.The water level of Y1-Y2 branch pipes gradually changes from more than half pipe flow to full pipe flow,to pressure flow,and finally overflow at the node.flow.(2)In view of the existing problems in the research community and the simulation results of the model's rain control in the current community,four sponge technical measures,namely permeable brick paving,grass planting brick paving,concave green space and grass planting ditch,were selected to complete the sponge design plan.Among them,the permeable brick paving area is 1584.7m2,the newly-added grass-planting brick parking space is 100.56m2,the grass-planting brick parking space is transformed into 843.07m2,and the newly-increased concave green area and grass-planting ditch area is 1934.7m2.(3)Based on the current underlying surface model of the study area,the sponge design model was established through the Info Works ICM model,and the total annual runoff of the sponge design underlying surface of the study area under the conditions of annual rainfall and evaporation in 2013 was obtained.The control rate is 72.4%;under the conditions that the design rain return periods are 1a,2a,5a,and 10 a,the stagnant water after the sponge transformation is mainly distributed in the rainwater garden areaof ??the community,and the depth of the stagnant water is 3.14 cm,4cm,193.5cm,respectively,20 cm,the number of overflow nodes in the drainage pipe network after the sponge transformation is 0,4,6,and 37 respectively.The water level of the branch pipes of Y1-Y2 section gradually changes from less than half pipe flow to full pipe flow,and then To the pressure flow,but there will be no overflow at the node.(4)Through comparative analysis of the total annual runoff control rate before and after the sponge transformation in the study area,the distribution of water accumulation points and the drainage capacity of the pipe network,it is found that under the same design rainfall conditions,the surface runoff after the sponge transformation is less than before the transformation 23.2%;under the conditions that the design rainfall return periods are 1a,2a,5a,10 a,the distribution of accumulated water in the study area has changed from roads to rain gardens,and the water level in the branch and trunk pipes of Y1-Y2 section after the sponge transformation is significantly higher than that of the transformation The front is low and will not overflow at the node.