The Storm Production Runoff And Pollution Characteristic Of Landscape Architecture In Mountain City

In recent years, as the LID design and practice, the urban parks with scenic water has become a major move of the urban infrastructure.Because of the beautiful environment, the city park themed by leisure and recreation surface runoff pollutants concentration is usually lower, so within the scope of the access to information is little related research reports, even more lacking in runoff process and the production characteristics of related research by underlying surface type,various of slope and rainfall intensity. The thesis combined with the national major water subject, Select slope with different characteristics of permeable brick, landscape green space and the asphalt pavement in Chong Qing garden show park, studied the influence of Rainstorm runoff runoff and the producing pollution characteristics using homemade portable outdoor artificial rainfall simulation. The results show that:(1) Underlying surface type directly affect the peak time of rainfall, runoff peak flow and runoff coefficient. Landscape green and permeable brick has good permeability and water retention, Not only can significantly reduce runoff peak flow, and runoff coefficient is low. The intensity of rainfall and slope on good permeability surface runoff coefficient influence is obvious, but smaller influence on impervious underlying surface.Under trial conditions, The runoff coefficient of the asphalt pavement,permeable brick and landscape green variation range are respectively:0.88~0.92?0.21~0.42?c0.1~0.22.(2) Rainfall intensity had significant effect on the characteristics of pollution.The higher rainfall intensity, runoff producing ran faster,peak concentration is higher, the faster the decline rate of pollutants.For the landscape green due to the runoff of soil erosion,The greater the rainfall intensity is,the higher of the COD,SS stable concentration will be.(3) The influence of underlying surface slope characteristics of pollution are differences due to different underlying surface property.The waterproof underlying surface such as Landscape green space,The greater the slope,runoff producing ran faster,peak concentration is higher, the faster the decline rate of pollutants;As the Impervious underlying surface, the slope only affect the peak concentration on the asphalt pavement.(4)Runoff pollutants concentration peaked on the beginning of runoff,reduce at different rates later.Underlying surface type directly affect the characteristics of runoff pollutants.Landscape green for SS and TP, permeable brick for SS and NH3-N, asphalt pavement for SS and TP. The landscape green affected by plant foliage and no hardening soil,the SS concentration always show higher state.a. Under the experimental conditions,The peak concentration range of different underlying surface runoff pollutants COD?SS?NH3-N and TP are : 14.8~23.9mg/L?213~356mg/L?0.68~1.16mg/L?0.67~1.51mg/L for Landscape green.15.9~18.3mg/L?168~202mg/L?5.71~5.85mg/L?0.26~.027 mg/L for permeable brick.15.7~23.5mg/L?115~189 mg/L?1.56~1.69 mg/L?0.32~0.53 mg/L for asphalt pavement.Among them,the TP of landscape green,the NH3-N of permeable brick,the NH3-N and TP of asphalt pavement beyond the requirement of water quality of surface water level V.Three kinds of underlaying surface runoff SS peak concentration is higher,With urban sewage concentrationb. Under the experimental conditions, different underlying surface runoff in the first 10 minutes of initial runoff average concentration almost meet the requirements of water quality of surface water level IV. Among them,The change of TP average concentration range on landscape green are 0.43~0.71mg/L.The change of NH3-N average concentration range on permeable brick are 2.16~3.79mg/L,beyond the requirement of water quality of surface water level V. The SS average concentration range of initial runoff by the underlying surface respectively are 119.3~147.6mg/L?35.4~60.0mg/L?24.6~33.2mg/L, Beyond the urban sewage plant pollutants emission Level 1 B standard.c.Under the experimental conditions, the pollutant and mean concentration of the three types of underlying surface runoff are Quite different. The SS average concentration change range of landscape green and permeable brick respectively are 84.4~138.6mg/L?15.8~36.1mg/L,beyond the urban sewage plant pollutants emission standards Level 1 B standard, 13.3~16.2mg/L for asphalt pavement, beyond the urban sewage plant pollutants emission standards Level 1 A standard. The TP of landscape green(0.43~0.71mg/L) and the NH3-N of permeable brick(2.16~3.79mg/L) between the water quality of surface water level IV~V.The rest of the indicators meet the water quality of surface water level III.After the runoff water quality stability,the permeable brick and the asphalt runoff water quality is almost consistent with the original rain water quality,the COD and SS concentration of landscape green space is higher than the original rain water quality,the NH3-N concentration Always lower than the original water 10% ~ 15%.Research results not only enrich the research of city rainwater utilization also for the runoff pollution control and landscape water environmental protection,Even provides the basis for the LID construction.