Study on Concentration Changes of Indicator Pollutants in Yilan Area before and after Opening of Xueshan Tunnel
| Autor: | LIN, GUOHUA, 林國華 |
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| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 This study is to analyze the trends of fluctuation in various indicator pollutants in Yilan county over the years since Chiang Wei-shui Memorial Freeway has been in operation, and to examine the extent of its impact on air quality. This study summarizes the monitoring data of air quality indicators in Yilan county from 1994 to 2018, including gas pollutants (NOx, NO, NO2, SO2, O3, CO) and particulate pollutants (PM10, PM2.5), so as to review the temporal changes of various pollutant concentrations in Yilan, to analyze the changes in the types of pollutants before and after the opening of Chiang Wei-shui Memorial Freeway, and to further explore whether there is a weekend effect. The results of the study show that in recent years, in order to meet the air quality standards, the government has imposed an overall control measures and adopted a management structure through air quality monitoring, emission control, and application of simulation. The government has also introduced various pollution source control and improvement programs to reduce air pollutant emissions. Except for O3, the concentrations of other air pollutants show a downward trend over the years, which shows the success of a stricter regulation. Even the air quality in Yilan is relatively clean, it still has room for improvement. The concentrations of O3 and other pollutants show opposite trends, both on the hourly and annual basis. The photochemical reaction process and the titration effect of nitrogen oxides can be reasonably explained. SOX is an important indicator pollutant for industrial sources, and its characteristics are evidently observed in Dongshan station in the adjacent industrial area. The weekend effect of each air index pollutant is discriminated with the change of hourly concentration. Most of the pollutants have a higher density level on weekdays than on the weekends, but PM2.5 and O3 have a special trend of fluctuation at different time periods (day and night). Since more than half of the sources of PM2.5 are derivative substances, the interpretation of their hourly changes must take the sources of other pollutants at the same time into consideration; O3 must be inferred from the photochemical reaction and the titration effect during day and night. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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