環保專案成果報告查詢系統

專案計畫編號	EPA-107-FA11-03-A032
經費年度	107
計畫經費	13,000 千元
預算科目	空氣品質監測
專案開始日期	2018/07/31
專案結束日期	2020/07/30
專案主持人	張士昱
主辦單位	監資處
承辦人	黃健瑋
執行單位	中山醫學大學(公共衛生學系)
專案分類	大氣空氣、環境監測及檢測
中文關鍵字	消光係數、散光係數、PM2.5化學成分、相對濕度
英文關鍵字	Extinction coefficient, Scattering coefficient, PM2.5 chemical component, Relative humidity
協同主持人	李崇德；周崇光
共同主持人
計畫聯絡人	張軒昂
計畫聯絡電話	04-24730022#19004
計畫聯絡信箱	indexsiberia@gmail.com

中文摘要	國內對於大氣能見度的監測缺乏具可比較驗證的客觀方法與連續即時量測數據，造成量測數據與民眾觀感落差，本計畫現針對板橋、西屯與小港測站執行大氣能見度監測作業，並比對不同能見度量測方法的效能，提供有效觀測數據。本計畫購置長距式能見度觀測儀(LPV-4)與開放氣流型散光儀(NGN-2a)，並完成監測設備間的比對測試，經ANOVA統計分析顯示在95 %信賴區間內，任兩機的量測值皆未達統計顯著差異，遂將測站站房與監測設備安裝於板橋、西屯與小港測站並逐時監測消光與散光係數。觀測期間各測站LPV-4觀測的消光係數(Extinction Coe.)與NGN-2a觀測的散光係數(Scattering Coe.)經線性迴歸分析，迴歸決定係數(R2)在板橋、西屯與小港測站分別為0.86、0.86與0.94，顯示各測站能見度儀與散光儀運作正常且穩定，觀測數據相關性良好。將「LPV-4觀測」、「氣象局人工觀測」、「氣象局能見度儀觀測」等3種能見度觀測方法所得能見度以T檢定判斷觀測方法的異同，經統計檢定結果顯示3種觀測方法的能見度在多數時期存在差異，原因來自觀測主體與空間代表性的差異。目前國內並無能見度相關的標準與指標，本計畫以視程-濕度區分能見度事件類型特徵與季節發生頻率，探討各類型能見度事件下PM2.5濃度及相對濕度對於能見度衰減的影響，並採用IMPROVE監測網發展的deciviews能見度指標評估三地的視覺空氣品質，分析視覺空氣品質的影響因子。降低PM2.5濃度對於減少能見度低於10 km的事件與提升視覺空氣品質有所助益；此外量測數據亦顯示在相同PM2.5濃度下，相對濕度(RH)越高，消光係數也越大，在相同消光係數時，質量消光效率隨RH增加而增加，皆呈現PM2.5在高濕環境潮解後影響能見度的現象，此一因素導致能見度不佳的時數高於PM2.5濃度超標導致的時數。若以PM2.5化學成分應用revised IMPROVE (Interagency Monitoring of Protected Visual Environments)迴歸式來推估消光係數，比較LPV-4量測消光係數，兩者在板橋、忠明、小港的結果相關性R2皆相當不錯(0.96、0.96、0.98)，顯示可以使用此方法評估化學組成減量對於能見度提升的效益。從中比較推估成分因子間的貢獻程度，板橋以硫酸鹽貢獻量最高，各成分占比在全年季節變化並不明顯，忠明、小港則是在冬季時硝酸鹽顯著影響能見度。其中硫酸鹽、硝酸鹽在各站皆為重要消光係數貢獻源，然而從PM2.5質量效率分析中，發現NO3-在PM2.5質量占比的增加會導致能見度的下降，亦會使得每單位PM2.5的消光貢獻上升。而SO42-占比的情形卻不相同，沒有明顯的趨勢，顯示避免高濃度的NO3-出現是改善能見度首要工作之一。透過正矩陣因子法(Positive Matrix Factorization, PMF)推估板橋、忠明、小港可能的污染源，並使用多元迴歸重建LPV-4消光係數，加入相對濕度修正，以了解PMF污染源對真實大氣消光係數的貢獻。結果顯示板橋測站全年各因子消光貢獻量最為平均、季節變化不明顯；忠明站以冬、春兩季消光係數較高，主要以硝酸鹽(RH)、燃煤與富含氯(RH)為影響消光係數的大宗，此三項為改善中部冬春季節能見度較不佳的優先建議管控污染源；小港以秋、冬兩季為高消光係數時期，硝酸鹽(RH)與車輛排放為主要消光貢獻源，尤其在冬季為能見度最差的季節，硝酸鹽(RH)影響了56.1 %的消光係數，為改善小港能見度的首要建議減量污染源。
中文關鍵字	消光係數、散光係數、PM2.5化學成分、相對濕度

中文摘要

國內對於大氣能見度的監測缺乏具可比較驗證的客觀方法與連續即時量測數據，造成量測數據與民眾觀感落差，本計畫現針對板橋、西屯與小港測站執行大氣能見度監測作業，並比對不同能見度量測方法的效能，提供有效觀測數據。本計畫購置長距式能見度觀測儀(LPV-4)與開放氣流型散光儀(NGN-2a)，並完成監測設備間的比對測試，經ANOVA統計分析顯示在95 %信賴區間內，任兩機的量測值皆未達統計顯著差異，遂將測站站房與監測設備安裝於板橋、西屯與小港測站並逐時監測消光與散光係數。觀測期間各測站LPV-4觀測的消光係數(Extinction Coe.)與NGN-2a觀測的散光係數(Scattering Coe.)經線性迴歸分析，迴歸決定係數(R2)在板橋、西屯與小港測站分別為0.86、0.86與0.94，顯示各測站能見度儀與散光儀運作正常且穩定，觀測數據相關性良好。將「LPV-4觀測」、「氣象局人工觀測」、「氣象局能見度儀觀測」等3種能見度觀測方法所得能見度以T檢定判斷觀測方法的異同，經統計檢定結果顯示3種觀測方法的能見度在多數時期存在差異，原因來自觀測主體與空間代表性的差異。目前國內並無能見度相關的標準與指標，本計畫以視程-濕度區分能見度事件類型特徵與季節發生頻率，探討各類型能見度事件下PM2.5濃度及相對濕度對於能見度衰減的影響，並採用IMPROVE監測網發展的deciviews能見度指標評估三地的視覺空氣品質，分析視覺空氣品質的影響因子。降低PM2.5濃度對於減少能見度低於10 km的事件與提升視覺空氣品質有所助益；此外量測數據亦顯示在相同PM2.5濃度下，相對濕度(RH)越高，消光係數也越大，在相同消光係數時，質量消光效率隨RH增加而增加，皆呈現PM2.5在高濕環境潮解後影響能見度的現象，此一因素導致能見度不佳的時數高於PM2.5濃度超標導致的時數。若以PM2.5化學成分應用revised IMPROVE (Interagency Monitoring of Protected Visual Environments)迴歸式來推估消光係數，比較LPV-4量測消光係數，兩者在板橋、忠明、小港的結果相關性R2皆相當不錯(0.96、0.96、0.98)，顯示可以使用此方法評估化學組成減量對於能見度提升的效益。從中比較推估成分因子間的貢獻程度，板橋以硫酸鹽貢獻量最高，各成分占比在全年季節變化並不明顯，忠明、小港則是在冬季時硝酸鹽顯著影響能見度。其中硫酸鹽、硝酸鹽在各站皆為重要消光係數貢獻源，然而從PM2.5質量效率分析中，發現NO3-在PM2.5質量占比的增加會導致能見度的下降，亦會使得每單位PM2.5的消光貢獻上升。而SO42-占比的情形卻不相同，沒有明顯的趨勢，顯示避免高濃度的NO3-出現是改善能見度首要工作之一。透過正矩陣因子法(Positive Matrix Factorization, PMF)推估板橋、忠明、小港可能的污染源，並使用多元迴歸重建LPV-4消光係數，加入相對濕度修正，以了解PMF污染源對真實大氣消光係數的貢獻。結果顯示板橋測站全年各因子消光貢獻量最為平均、季節變化不明顯；忠明站以冬、春兩季消光係數較高，主要以硝酸鹽(RH)、燃煤與富含氯(RH)為影響消光係數的大宗，此三項為改善中部冬春季節能見度較不佳的優先建議管控污染源；小港以秋、冬兩季為高消光係數時期，硝酸鹽(RH)與車輛排放為主要消光貢獻源，尤其在冬季為能見度最差的季節，硝酸鹽(RH)影響了56.1 %的消光係數，為改善小港能見度的首要建議減量污染源。

中文關鍵字

消光係數、散光係數、PM2.5化學成分、相對濕度

類型	檔名	檔案大小	說明	最新版公開日期
期末報告	空氣能見度監測規劃及應用服務(公開版).pdf	25MB	顧及個資隱私，未包含機敏個人資訊	2020/10/1 上午 12:00:00

摘要	In Taiwan, monitoring of atmospheric visibility lacks objective methods and continuous real-time measurement data, which result in a gap between measurement data and public perception. This work proceeded with visibility measurements at the Banqiao, Xitun, and Xiaogang air quality monitoring sites of Environmental Protection Administration from March 2019 to June 2020. In addition, the different visibility measurement methods were compared to provide valid observation data. This work set up the visibility monitoring technology equipped with Long Path Visibility Transmissometers (LPV-4) and Open-Air Integrating Nephelometers (NGN-2a). Within 95% confidence interval with ANOVA statistical analysis, the simultaneous measurements from three LPV-4 instruments were regarded as the same. There was also not statistically significant difference among three NGN-2a simultaneous measurements. After verifying the measurement consistency of the instrument, monitoring stations and instruments were installed at the Banqiao, Xitun, and Xiaogang sites and conducted to investigate continuous hourly extinction and scattering coefficient. The linear regression analysis showed extinction coefficient correlated well with scattering coefficient at the Banqiao, Xitun, and Xiaogang sites, respectively (R2 = 0.86, 0.84 and 0.93), which indicated that the instruments operated normally and stably. However, the results of T-test for visibility measurements from LPV-4, Central Weather Bureau (CWB) human observation, and Visibility ＆ Present Weather Sensor (SWS-250) revealed three methods were significantly different during most measurement periods. The possible reasons were the individual vision objective and the differences of observed environment. So far, the domestic standards and indicators of visibility has been not established. To evaluate of visibility reduction by PM2.5 (an aerodynamic diameter equal to or less than 2.5 μm) concentration and relative humidity (RH), this work distinguished the characteristics and occurrence frequency by visual range (VR) and RH at different visibility event. Additionally, visibility indicator (deciviews) developed by Interagency Monitoring of Protected Visual Environments (IMPROVE) was used to evaluate visual air quality and effect factors at the Banqiao, Xitun, and Xiaogang sites. Reducing concentration of PM2.5 is beneficial to decrease frequencies of visibility events ( VR < 10 km) and improve visual air quality. Under the same PM2.5 concentration condition, the extinction coefficient was proportional to the RH. In addition, the extinction mass efficiency also increased with the RH at the same extinction coefficient. It indicated that the hours of visibility events caused by the deliquescence of PM2.5 were more than those caused by excessive PM2.5 concentration. The PM2.5 chemical compositions were applied to the revised IMPROVE regression to estimate the extinction coefficient. The estimated extinction coefficient was correlated well to measured extinction coefficient by LPV-4 with R2 of 0.96, 0.96, and 0.98 at Banqiao, Zhongming, and Xiaogang, respectively. It indicated that the estimated extinction coefficient could be used to evaluate the contributions of chemical compositions reduction in visibility improvement. At the Banqiao site, the highest contributive composition to the light extinction coefficient was sulfate, and the contributive proportion of each composition did not change apparently throughout the seasons. Nitrate significantly affected visibility at Zhongming and Xiaogang in winter. Regarding the contributions of PM2.5 chemical compositions in extinction coefficient, sulfate and nitrate are important contribution sources of extinction coefficient at each site. According to the relation between PM2.5 mass extinction efficiency and chemical compositions, it was found that the increase in the proportion of NO3- in PM2.5 mass would lead to the decrease in visibility and the increase in mass extinction efficiency. Although, the high proportion of sulfate in PM2.5 is an obvious characteristic, the mass extinction efficiency was not ascended as increase in the mass proportion of sulfate. The results indicated that avoiding the emission and formation of nitrate is one of the primary solution to improve visibility. For source apportionment of pollution, positive matrix factorization (PMF) was used at the Banqiao, Zhongming, and Xiaogang sites, and this work reconstructed the LPV-4 extinction coefficient with PMF factors and modified with relative humidity factor to understand the contribution of the sources in the real atmospheric environment. The results showed that the extinction coefficient of each source did not show the obvious seasonal variation at Banqiao site. The extinction coefficient at Zhongming was higher in winter and spring, which mainly contributed by sources of nitrate (RH), coal-burning, and chlorine-rich (RH). Reducing of the extinction coefficient from these three contribution sources was the primary recommendation to improve visibility. At Xiaogang site, the nitrate (RH) and vehicle emissions were the main contribution sources of extinction coefficient, which caused the high extinction coefficient in autumn and winter. Especially in winter, nitrate (RH) affected the 56.1% of extinction coefficient. As a result, reducing the source of nitrate (RH) might be one of the important solutions for improving the visibility.
英文關鍵字	Extinction coefficient, Scattering coefficient, PM2.5 chemical component, Relative humidity

摘要

In Taiwan, monitoring of atmospheric visibility lacks objective methods and continuous real-time measurement data, which result in a gap between measurement data and public perception. This work proceeded with visibility measurements at the Banqiao, Xitun, and Xiaogang air quality monitoring sites of Environmental Protection Administration from March 2019 to June 2020. In addition, the different visibility measurement methods were compared to provide valid observation data. This work set up the visibility monitoring technology equipped with Long Path Visibility Transmissometers (LPV-4) and Open-Air Integrating Nephelometers (NGN-2a). Within 95% confidence interval with ANOVA statistical analysis, the simultaneous measurements from three LPV-4 instruments were regarded as the same. There was also not statistically significant difference among three NGN-2a simultaneous measurements. After verifying the measurement consistency of the instrument, monitoring stations and instruments were installed at the Banqiao, Xitun, and Xiaogang sites and conducted to investigate continuous hourly extinction and scattering coefficient. The linear regression analysis showed extinction coefficient correlated well with scattering coefficient at the Banqiao, Xitun, and Xiaogang sites, respectively (R2 = 0.86, 0.84 and 0.93), which indicated that the instruments operated normally and stably. However, the results of T-test for visibility measurements from LPV-4, Central Weather Bureau (CWB) human observation, and Visibility ＆ Present Weather Sensor (SWS-250) revealed three methods were significantly different during most measurement periods. The possible reasons were the individual vision objective and the differences of observed environment. So far, the domestic standards and indicators of visibility has been not established. To evaluate of visibility reduction by PM2.5 (an aerodynamic diameter equal to or less than 2.5 μm) concentration and relative humidity (RH), this work distinguished the characteristics and occurrence frequency by visual range (VR) and RH at different visibility event. Additionally, visibility indicator (deciviews) developed by Interagency Monitoring of Protected Visual Environments (IMPROVE) was used to evaluate visual air quality and effect factors at the Banqiao, Xitun, and Xiaogang sites. Reducing concentration of PM2.5 is beneficial to decrease frequencies of visibility events ( VR < 10 km) and improve visual air quality. Under the same PM2.5 concentration condition, the extinction coefficient was proportional to the RH. In addition, the extinction mass efficiency also increased with the RH at the same extinction coefficient. It indicated that the hours of visibility events caused by the deliquescence of PM2.5 were more than those caused by excessive PM2.5 concentration. The PM2.5 chemical compositions were applied to the revised IMPROVE regression to estimate the extinction coefficient. The estimated extinction coefficient was correlated well to measured extinction coefficient by LPV-4 with R2 of 0.96, 0.96, and 0.98 at Banqiao, Zhongming, and Xiaogang, respectively. It indicated that the estimated extinction coefficient could be used to evaluate the contributions of chemical compositions reduction in visibility improvement. At the Banqiao site, the highest contributive composition to the light extinction coefficient was sulfate, and the contributive proportion of each composition did not change apparently throughout the seasons. Nitrate significantly affected visibility at Zhongming and Xiaogang in winter. Regarding the contributions of PM2.5 chemical compositions in extinction coefficient, sulfate and nitrate are important contribution sources of extinction coefficient at each site. According to the relation between PM2.5 mass extinction efficiency and chemical compositions, it was found that the increase in the proportion of NO3- in PM2.5 mass would lead to the decrease in visibility and the increase in mass extinction efficiency. Although, the high proportion of sulfate in PM2.5 is an obvious characteristic, the mass extinction efficiency was not ascended as increase in the mass proportion of sulfate. The results indicated that avoiding the emission and formation of nitrate is one of the primary solution to improve visibility. For source apportionment of pollution, positive matrix factorization (PMF) was used at the Banqiao, Zhongming, and Xiaogang sites, and this work reconstructed the LPV-4 extinction coefficient with PMF factors and modified with relative humidity factor to understand the contribution of the sources in the real atmospheric environment. The results showed that the extinction coefficient of each source did not show the obvious seasonal variation at Banqiao site. The extinction coefficient at Zhongming was higher in winter and spring, which mainly contributed by sources of nitrate (RH), coal-burning, and chlorine-rich (RH). Reducing of the extinction coefficient from these three contribution sources was the primary recommendation to improve visibility. At Xiaogang site, the nitrate (RH) and vehicle emissions were the main contribution sources of extinction coefficient, which caused the high extinction coefficient in autumn and winter. Especially in winter, nitrate (RH) affected the 56.1% of extinction coefficient. As a result, reducing the source of nitrate (RH) might be one of the important solutions for improving the visibility.

英文關鍵字

Extinction coefficient, Scattering coefficient, PM2.5 chemical component, Relative humidity