Impact of biomass burning and its control on participate matter over a city in mainland Southeast Asia during a smog episode

摘要

Cities in mainland Southeast Asia have long faced smog problems. Developing effective control strategies for smog reduction has been a challenge for academics and policy makers. In this study, emission control measures were assessed using both the Weather Research and Forecasting (WRF) and Community Multi-scale Air Quality (CMAQ) modeling systems during a smog episode between 1st and 31st of March 2012. The study found that there was a strong impact from biomass burning outside of the city on PM concentrations within the city, with contributions of approximately 85% and 89% for PM10 and PM2.5 respectively. Control of biomass burning in the city significantly affects local PM concentrations. This study investigated the success of biomass burning control inside the city when no biomass is burned outside of the city. The control scenarios focused on specific reduction levels in biomass burning emissions, which included 0%, 20%, 40%, 60%, 80% and 100%. The results yielded the following rates: the mean PM2.5 concentrations decreased by 0.70% per %decrease of biomass burning emission; the maximum daily average PM2.5 concentrations decreased by 0.84% per %decrease of biomass burning emission; and the average percentage of PM2.5 concentrations that exceeded the NAAQS decreased by 1.05% per %decrease of biomass burning emission. This information provide good guidelines for successful decision-making at each control level to solve the problems related to of smog in cities. However, smog problems cannot only be solved by emission control measures in the city; biomass burning must also be reduced on a regional scale.