| Summary: | 碩士 === 國立中興大學 === 環境工程學系所 === 106 === In recent years, raise of eco- awareness, air pollution problem is become one of the issues people concerning，one of the most people concern about is PM2.5,which is solid or liquid particle with a diameter of 2.5 micrometers or less. When these particles enter the respiratory tract, it can directly pass the alveoli and enter the blood vessels, which harmful to the body. The source of research data in this study is supplied from air quality monitoring station in central Taiwan air basin during 2010-2014, to find PM2.5 and other index pollutants variation in central Taiwan air basin. The research methods are descriptive statistics, correlation analysis, factor analysis and wind rose diagram.
The results show the concentration of PM2.5 is decreasing year by year, the concentration in summer is lower, and has higher concentrating in daytime. The PM10 concentration distribution is similar to PM2.5, and it is also decreasing year by year；The O3 concentration is increasing year by year, the concentration is higher in spring and autumn, is lower in summer, and the high value is the most frequently at summer. It is related to sunlight is stronger in summer than other season；The concentration of NO is decreasing year by year, and the concentration in summer is lower than that in other three seasons. The high value is easy to occur in winter, the NO concentration is lower at noon, and the concentration is higher from the evening until about early morning； The concentration of NO2 has a decreasing trend year by year, the summer concentration is the lowest, the winter is slightly higher than the spring and autumn, and the daily concentration is the lowest at midday. The CO concentration has a decreasing trend year by year, and the summer concentration is the lowest. The daily concentration is 8:00 am to 9:00 am and the night. It is higher from 8:00 to 10:00; Also the concentration of SO2 has a decreasing trend year by year, but this trend is not obvious. It means SO2 concentration is relative stable. The meteorological factors show temperature is slowly rising every year. Summer has the highest temperature and winter has the lowest temperature. The lowest daily temperature is fall at 7 a.m. and the highest is fall at 3 p.m. The relative humidity does not change much in the year and season, only there are fewer extremes in summer. The relative humidity change in the day can found that the relative humidity is low at noon. The rainfall part can be seen that there is less rainfall in 2011 and there is the most rainfall season in summer.
Correlation analysis results show that PM2.5 in the central air basin is positively correlated with PM10, NO, NO2, O3, CO, SO2, and negatively correlated with temperature, rainfall, relative humidity and wind speed. If PM2.5 is taken more than the maximum upper limit value, it can be found that the correlation coefficient between PM2.5 and other indicators of pollutants and meteorological factors is greatly reduced. The results of factor analysis show that there are four factors affecting the air quality in the central air basin. Factor 1 is composed of CO and NOx, factor 2 is composed of suspended particles, factor 3 is ozone, and factor 4 is SO2.
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