Study On The Variation And Prediction Method Of Ozone Concentration In Beijing Urban Area

High concentrations of urban O3 pollution occur frequently, that caused great harm to human, animal,plant and the building. Therefore, it is very important to enhance the study of the variation of O3 ozone in traffic road where the concentration of O3 precursors is high.The monitor and study the O3 concentration distribution in urban, besides the prediction of O3 concentration is also meanful.In this paper,the observational data around Beijing typical roads in four seasons and the data of the six observation points in northwest of Beijing arban was analysed, and then, the variation of ozone in traffic road and the other urban area was studied. At the same time, by the summary of the method of O3 concentration,the study of the quick O3 concentration forecast model based on meteorological factors which carried out using BP neural networks, genetic algorithm and support vector machine was conducted.The variation of O3 around traffic road show that:The diurnal variation of O3 concentrations around three typical traffic roads show a very clear cycle with one peak. The order from high to low of the O3 season average concentration is:summer,spring,autumn,winter,diurnal variation of O3 concentration in spring and summer is much higher than in other seasons; When in the same season, O3 concentration varies in different context and the peak time is also different around different typical road.Generally speaking, O3 concentration varies in smaller range around open road especially in summer;No matter what the season is, the correlation between O3 concentration and the concentration of NO and NMHCs is definite,which is obvious negative. The correlation between O3 and NO2,[NO2]/[NO] is not so clear, which is positive in summer and negative in other seasons;O3 concentration is positive correlated with UV radiation and temperature while negative in all three typical roads.The correlation between O3 concentration and UV radiation is worse, especially in street canyon road area;The O3 concentration in traffic road is not higher than in the reference point, the variation of O3 concentration around traffic roads is accordance with the whole city only the peak time is different.The variation of O3 in northwest of Beijing arban show that:O3 pollution in Beijing urban areas is still serious, the O3 concentration increased from central city to the edge of the city in the same season, but the trend of increasing is not obvious. The daily average concentration of O3 changed significantly with the seasons, which is lowest in winter and highest in summer.In addition, the study of the quick O3 concentration forecast model tell us that:lt is effective to forecast O3 concentration by the the GABPNNs with SVM classification,the mean value of consistency coefficient and Correlation coefficient is 0.9478 and 0.8830.