A comparative study on the effect of transboundary long-range transport on Taiwan's air quality by two different simulation methods

• Main Authors: Cheng-Min Hung, 洪晟閔
• Other Authors: Ken-Hui Chang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/09661525898277675072

碩士 === 國立雲林科技大學 === 環境與安全衛生工程系 === 102 === Brute Force Method (BFM) wars mostly adopted to calculate the difference of two scenarios, however, this method costs plenty of time for computation. The Decoupled Direct Method (DDM) is a direct method to calculate sensitivity by directly solving sensitivity governing equation to obtain the contribution when emission changes, so DDM saves more time than BFM when discussing the emission changes. The study discussed the difference between BFM and DDM for simulating long-transport influence in CMAQ, in Taiwan, 2007. First, the results indicated the correlation coefficient between the two methods is about 0.909-0.984 in different regions that suggested the consistency in the two methods. Second, because of the primary PM concentration between source and receptor approximately linear relation, the two simulation results of PM2.5 for the methods are closed. Finally, this study only used first-order DDM, so the simulation results can not explore the nonlinear pattern of secondary aerosol. Consequently, the PM2.5 simulation results using DDM were less than that using BFM, and DDM/BFM were about 0.54-0.68 in different regions. Also, this study used CMAQ model with first-order DDM to evaluate the long transport effect in Taiwan against Asia in coarse grid (81km × 81km) in 2010. The monthly average PM2.5 concentration in February, May, August and November represented the annual concentration. The simulation results suggested that area average concentration of PM2.5 in Taiwan is 13.69 g/m3 and the influence from East Asia transport was 4 g/m3 (29%), China accounted for 91%. Among the six area in China, Taiwan is most seriously affected by East China whose contribution was about 1.84 g/m3 (accounting for 50% of China's influence). The main source of air pollution in China was factory industry; other sources of air pollution in order are the power plant residential, mobile, and agriculture.