利用卫星遥感评估广西壮族自治区SO2减排成效

基于2005—2012年OMI卫星遥感PBL SO2柱浓度数据分析了广西壮族自治区SO2污染的时空格局和变化特征,并结合燃煤火电厂SO2排放模型估算与工业经济增长数据,在时间、空间尺度上分析了自治区内不同区域的SO2污染对火电厂烟气脱硫政策的响应以及所呈现出的减排成效。结果表明,广西因火电厂脱硫政策驱动的SO2污染改善具有显著的空间异质性,自治区内高污染区的SO2浓度在2011—2012年出现了显著下降,而低污染区的SO2浓度则在8年中持续增长;排放模型估算结果显示,烟气脱硫驱动的火电厂SO2减排贡献将在2008年后持续下降,而遥感观测结果显示,广西全区SO2半年浓度均值总体呈现波动上升趋势,2005—2012年浓度增加了8.6%、年均增长约0.9%;综合工业经济增长数据发现,近年来其他工业源的增量排放已给广西SO2减排带了新挑战,而这一变化仍未得到相关决策部门关注,存在明显缺陷的SO2统计排放量数据尚未得到修正。针对上述污染变化新特征,政府相关部门应引起足够重视,尽快更新完善污染源信息并启动针对其他污染源的限排措施,以确保环境持续改善。

Analysis on effectiveness of SO2 emission reduction in Guangxi Zhuang Autonomous Region by satellite remote sensing

The SO2 emissions from coal-fired power plants in China were regulated by a mandatory installation of flue gas desulfurization (FGD) devices since 2005. In order to evaluate the effectiveness of FGD in regional SO2 emission reduction, the spatio-temporal characteristic of SO2 densities over different regions in Guangxi Zhuang Autonomous Region during 2005—2012 were investigated by using the satellite remote sensing data from the Ozone Monitoring Instrument (OMI). Bottom-up emission estimate model of coal-fired power plants and industrial economic growth data were also employed in the analysis of regional SO2 pollution. The main conclusions are as follows: the reduction of regional SO2 pollution attributed to FGD showed obvious spatial heterogeneity. The SO2 densities over high-polluted regions showed a notable decline during 2011—2012, while those over low-polluted regions showed a successive increase during 2005—2012. Bottom-up emission estimates for power plants indicated that the emission reduction owing to FGD would decline significantly since 2008, while the annual mean SO2 density over the whole Guangxi observed by OMI showed an increase by 8.6% during 2005—2012, with an annual average growth rate of 0.9%. Giving the high growth rate of industry, the emitting increments from other unregulated emission sources have become a new challenge for the SO2 pollution in Guangxi. But such phenomenon has not been known by the regulars and the static emission data with obvious errors noted by Department of Environmental Protection have not been updated yet. In view of the new trends in SO2 pollution in Guangxi, more reasonable and mandatory policies for sustainable developments, such as the installation of FGD systems in other large emission sources, should be pushed out in the near future.