1993∼2006台灣中部及雲嘉南地區空氣品質變遷與原因探討

Abstract

摘要 本研究主要針對1993∼2006年間，中彰投雲嘉南地區之環保署21個測站進行歷年污染物濃度資料統計分析，觀察各污染物之歷年變遷，並找出污染源與污染物觀測值之間的關析。經過統計後，臭氧與懸浮微粒為最主要污染物質，而其他污染物的趨勢並不一定。近五年來臭氧上升程度十分嚴重，最嚴重的測站為竹山測站；懸浮微粒則是許多地區有下降的趨勢，懸浮微粒污染最嚴重的地區為嘉義測站、後甲測站，上升的地區主要為嘉義縣最明顯。 由於氣象條件的變化以長時間來觀察較為緩和，並不太可能造成污染在某時間後快速惡化嚴重；因此本研究找尋造成污染變遷之可能原因，對照污染年份與中南部重大建設之時間，並檢驗環保署測站之歷年風向風速分佈情況、觀察近年來風速風向之變化，最後透過逆軌跡來觀察造成測站事件日的污染來源。發現近年來的較嚴重污染測站，由於風速較小容易造成污染的氣象條件為：較弱的東北季風，導致這些地區污染物擴散不易；六月份夏季時的西風，將污染物吹向內陸，造成污染，其他月份主要由鄰近的北方都會區與電廠由北而南帶來的污染。分析年份與逆軌跡後發現，中部臭氧最主要的污染來排放源是來自於中台灣的污染源，台中火力發電廠、台中都會區、台北市、苗栗通霄電廠，而台南的安南與後甲則與六輕、嘉義市、台北市等較有關係。

Abstract The main study is to analyze the change of pollutions from 1993 to 2006, according to the pollutants statistics of 21 air quality monitoring stations in Taichung, Changhua, Nantou, Yunlin, Chiayi, and Tainan. The research can find out the relationship between pollution source and the statistic result of pollutant database. By statistics, it shows there is a tendency that pollutions, except for ozone pollution and PM10, had decreased. Especially in Jushan station, it is very serious in these five years. Otherwise, some regions shows a decreasing trend of PM10. The region of Chiayi, however, has obviously increased. Although the air quality change in a long term is much slower by the observation, the research needs to understand what are vital pollution sources resulting in that change. By comparing with polluted years and the time of building major infrastructures in the central and south region, examining the distribution of wind direction and wind speed, and finally using backward trajectory, the result reveals two reasons why the air quality changes. One is that the weak wind in fall causes the pollution concentration not to disperse easily. Another is sea-land breeze which brows pollutions back to the land. Moreover, the major pollution source is from the central region, such as the Formosa Plastic Group’s Sixth Naphtha Cracking Plant, Taichung fire power plant, Taichung metropolis, Chiayi metropolis, and Maioli fire power plant. To sum up, they are related to the air quality change.