Research For The Effect Of Controling Pollution And Peak Runoff In Residential Area Based On SWMM

While the urbanization has changed the hydrologic characteristics of basins, the existing stormwater drainage system is overburdened. Then many cities have suffered different degrees of floodings, and the pollution of the initial rainwater has affected the water environment seriously. So the low-impact development(LID) which bases on the source control is introduced. Wuhan is a large and typical city, which suffered the serious pollution of rivers and lakes. So solving the flood and controling the runoff pollution have became an important issue in Wuhan. Research on the LID technology has great significance, which can manage the stormwater, make up the the lack of stormwater management measures and improve the current situation.The paper selected the Poly Rafi community inWuhan City as the study object,and selected the appropriate measures,then built the hydraulic and quality model of the study area with SWMM. By simulating water quantity and quality before and after settings LID measures, the combinations of LID measures were find for different requirements, finally the LID setting standards were provided.The major paper results are showed as follows:(1) The results simulating rainfall runoff of Poly Rafi's before and after its development showed that the runoff increase greatly after its development.(2) The simulation has got the flow progresses of the outlet P1 after setting the single LID measure and the reducing rate under different return periods.(3)The standard of LID combination regimen which the main function was clipping the flow peak was proposed:The areas of the 70% parking lot and sidewalk were porous pavements,accounting for 6.25% of the total area of the community.);The areas of the 30% the lawn were vegetation swales,accounting for 15.3% of the total area of the community,and its recessed depth of 125 mm.The standard of the split storage tank was 267m3 per 10000m2 curing,and the shunt pipe raise 5-6cm from the bottom of the pipe.(4)The paper has got the pollutants' reducing rates of LID measures which are the closure storage tank(200m3 per 10000m2 curing),30% vegetation swales,the ministorage tank(45m3 per 10000m2 curing),the split storage tank(135m3 per 10000m2 curing) and 70% porous pavements.(5) The paper has got the parameters the LID combination regimens which controlled 15 mm and 25 mm of rainfal respectively.(6)The standard of LID combination regimen which the functions were both clipping the flow peak and pollution was proposed:while the areas of the 70% parking lot and sidewalk were porous pavements,the areas of the 30% the lawn were vegetation swales and its recessed depth of 125 mm.The standard of the split storage tank was 500m3 per 10000m2 curing to match the rainfall of 10 a.The results of simulating and analysis for the single LID measure and its combinations can provide technical supports to promote the application of LID techniques in Wuhan.