| With the developing of Harbin economy and the improving of the people lives level, the consumption amount of fossil energy and the number of vehicles increase year by year, and it makes pollutants of all kinds of pollution sources discharge to atmospheric increased. Under the interaction of pollutant emissions increasing and the special weather conditions, fog and haze occur in Harbin area frequently, especially in municipal district. Long distance transmission of burning straw in surrounding areas also affects air quality. Therefore, analyzing quality of Harbin municipal district air, exploring the causes of haze, tracing the source of pollutants and determining the subduction of pollution sources according to the future requirements of the air quality in Harbin are very necessary.The WRF/CALPUFF/HYSPLIT coupling system is selected in this study. Firstly, according to model working principle, requirements of input parameters, it determines the actual simulating scheme and model parameters, combined with unique geographical and meteorological conditions of Harbin municipal district. It counts emissions data of air pollution sources and analyzes the characteristics of pollution sources in Harbin municipal district and create the air pollution source emission database of Harbin municipal district.The study discusses air quality of Harbin municipal district with WRF/CALPUFF coupling system. Comparing simulated pollutants concentration to monitoring concentration, the results show that the coupled system can reflect the actual air quality of Harbin municipal district basically. SO2, NO2 and PM2.5 simulated concentration is correlated to monitoring measured concentrations positively, with eighty percent. Then the system is used to simulate concentration of three kinds of air pollutant and spatial distribution during the heating period and non-heating period. Analyzing effects of different meteorological conditions on air quality and contribution of concentration in two periods, results show that average concentration of SO2, NO2 and PM2.5 are 126?g/m3、68?g/m3、123?g/m3 during heating period, average concentration of SO2, NO2 and PM2.5 are 8?g/m3、68?g/m3、49?g/m3 during non-heating period. Daoli、Pingfang、Nangang district are in the top three of the concentration of pollutants. In the heating period the average wind speed is less than 2m/s, the average mixed layer height being 455 m and atmosphere to weakly stable(E) and(f) mainly, the night of the mixed layer height being generally less than 200 m, at the bottom of the inversion layer height being 100 m. Therefore, the weather is not conducive to the vertical direction of the air flow. In the non-heating period, the atmospheric is instability.The study simulates a serious haze weather of October 2014 with WRF/CALPUFF/HYSPLIT system, tracing back and tracing the pollutions. The results show that the upper air pollutants come from Inner Mongolia and lower pollutants come from Inner Mongolia and Liaoning Province. Finally, according to the requirements of air quality for next three years and simulation results, the study determines the reductions of source emission in Harbin municipal district, which provides a theoretical basis for air pollution forecasting and warning. Simulation results show that during the heating period and severe smog when the concentration of PM2.5 reduced for each tested 100?g/m3, it needs to reduce soot emissions 2.60 million tons/year and 2.86 million tons/year. |
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