Representation of Air Quality Monitoring System in Central Taiwan

• Main Author: 周經芳
• Other Authors: Wan-Li Cheng
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/51283324444060121803

碩士 === 東海大學 === 環境科學系 === 87 === The major Air Quality Monitoring Systems in Central Taiwan are EPA (the Environmental Protection Agency) and the Taichung Coal-Fired Power Plant. When analyzing SO2 and NO2 data, I find that the concentration of the Power Plant’s stations is much higher than EPA’s. I based on the SO2 and NO2 data of the two stations from October 1995 to September 1997 and picked five pairs of ten neighboring stations from two Air Quality Monitoring Systems to compare and analyze. They are Changhua* (both have stations), Chiensi* (both have stations), Tonghai and Shitun, Wuchi and Shalu, Chawtwin and Nanto. Statistical methods, of regression analysis, factorial design, intervention analysis and cross spectra analysis, were used to evaluate the difference between the two systems. The Power Plant’s monitoring data is higher than EPA’s for the annual and monthly variation of SO2 and NO2.SO2 is 1.8~2.9 times, as high and NO2 1.1~1.4 times, so the large influence is on SO2. Fixed sources are the dominant factor for SO2. The differences of the two Changhua* stations, Wuchi from Shalu, Chawtun from Nanto are larger than other’s neighboring pairs. Environment is the main factor for the Changhua* stations. The pollution source is the main factor for Wuchi and Shalu, and for Chawtun and Nanto, and the difference changes with the seasons. NO2 has similar pollution behavior, with two peaks each day, mainly affected by vehicles. According to intervention analysis, long distance pollution sources have a slight impact on stations’ data. Among neighboring stations, the Changhua* stations, and Tunghai and Shitun stations, Chawtwin and Nanto stations have similar pollution behavior. The Changhua* stations, and Tonghai and Shitun stations are affected by the same source. Chawtun and Nanto stations are affected by mobile sources. In summer, the com-period of Wuchi and Shalu from the phase diagram is deviation, SO2 variation has a delay of about three days, and NO2 about one day, which is possibly from the Taichung Power Plant. Parallel monitoring shows that, the difference between identical instruments, for SO2 is about 1 ppb, NO2 about 1~3 ppb, and the difference between different-brand instruments is less than 2 ppb. Therefore, the difference between instruments is not the main factor. The integration of the two systems should be possible, but because the differential of SO2 is large, we can’t directly use contouring. But we can use a regression equation to accomplish local integration. For the dispersion of NO2, the difference with every season is similar. We can directly subtract 4~5 ppb from the power plant’s stations’ data and combine it with EPA’s stations, which can improve the understanding of NO2 in Central Taiwan. The empirical equation from parallel monitoring, proves to be better than a regression equation with local integration.