Study On Runoff Pollution And Control Measuers Of Parking Lot In China Cities

As one of the urban infrastructure, parking lot holds a large proportion in the urbanimpervious area. Through collecting the design material of domestic and foreign parking lotand spot investigation, Characteristics of parking lots and their negative effects toenvironment ware analyzed. Firsh flush effect in representative parking lot was researchedthtough runoff collection and determination. Combined with the characteristic of runoff, thedesign concept and overall scheme of stormwater management practices for Chinese parkinglots was presented.Analysising the application of main stormwater management practices in parking lot, thesize of those practices on different control target was put forward. By presenting cases studyof retrofits, It was pointed out that the design and construction of environment-friendlyparking lot incorporated with stormwater management practices should be established as soonas possible in Chinese cities. The main contents and conclusions are as follows:(1) With lower design index at present and high demand in future for parking lot, the totalarea of parking lot in future in cities was estimated.(2) Mang negative effects to environment of parking lot was presented and it was found thatthe afforestation rate of parking lot in Beijing was less than12%.(3) By collection, monitoring and analysis the runoff of parking lot in exhibition center, firshflush effect was researched, the main conclusion are as follows:EMC of runoff pollutants (such as COD, SS) in domestic parking lot ware higherthan developed countries.The total rainfall was2~4.8mm when EMC of runoff pollutants was below100mg/L.Firsh flush effect was detectived when the initial rainfall intensity in frist5minute(i5)was higher than0.16mm/min.The MFFn factor of runoff pollutants and the initial rainfall intensity i5was into astraight line relationship when i5was higher than0.2mm/min.The pollution load of runoff in parking lot cities was estimated in Beijing Shanghaiand Guangzhou.(4) With the concept of comprehensive utilization of stormwater, the overall scheme of storm-water management practices for Chinese parking lots was presented.(5) The application of permeable pavement(with porosity of10%~20%)、grass swale(with thewideth is1~3m) and raingarden in parking lot ware put forward.(6) The layout and design method of scale of practices was presented, the main conclusion areas follows:the layout of practices include distributed, centralized and combined-type withdifferent afforestation rate in parking lot. In the condition of changing soil, the cover rate of practices was4%~9%underdifferent permeability coefficient (with controlling10mm, concave depth was5to15cm).Without changing soil, the cover rate of practices was5%~21%under differentpermeability coefficient.The relationship between design rainfall and control rate of total rainfall wascalculated in different afforestation rate(7) The feasibility of stormwater management practices in parking lot was verified throughsome design cases and those economic analysis. the promotion of stormwater managementpractices in parking lot also needs government’s encourage policy and designe concept.