利用OMI卫星遥感评估贵州省SO_2减排成效

Effectiveness evaluation of SO_2 emission reduction in Guizhou Province by OMI satellite remote sensing

为评估燃煤火电厂烟气脱硫减排政策对地区SO_2污染的影响,本研究基于OMI卫星遥感SO_2柱数据,对贵州省2005—2012年的SO_2时空变化特征进行了分析,并结合火电厂SO_2排放量模型估算数据,从时间空间尺度上测算了省内不同区域的污染变化趋势及区域污染对火电脱硫政策的响应。结果表明:(1)贵州省SO_2污染强度在2008年后出现了小幅下降趋势,但省内污染改善呈现出显著的空间异质性,工业欠发达地区的污染强度未得到明显改善、部分区域甚至表现出持续增长的趋势。(2)烟气脱硫政策并未驱动贵州省火电厂周边区域的SO_2污染出现一致性改善,部分区域污染在电厂烟气脱硫后仍然呈现出增长的趋势;基于SO_2浓度与年份的相关性分析表明,单一的烟气脱硫政策对于贵州省SO_2污染治理存在着明显的局限性,工业欠发达地区的污染变化未因减排政策实施而呈现出下降趋势。(3)基于火电厂排放清单模型的排放量估算表明,贵州省2009年后来自于火电领域的SO_2减排贡献已显著下降,未来的减排政策应更多地关注其他污染源的排放约束,以确保省内大气污染得到持续、全面的改善。

In order to evaluate the impact of the emission reduction policy for coal-fired power plants on regional SO2 pollution, the spatio-temporal variation characteristics of the SO2 density by satellite remote sensing from the Ozone Monitoring Instrument （OMI） and the emission estimate by inventory in Guizhou province from 2005 to 2012 were investigated. Then the variation trend of pollution and the response of pollution to policy in different area were analyzed by GIS methods on the spatio- temporal scale. The main conclusions were as follows： （1） The overall SO2 densities of whole Guizhou declined moderately after 2008, but the reduction in regional SO2 pollution showed an obvious spatial heterogeneity. In industrial underdeveloped area, the improvement for pollution was scarce and the SO2 densities have kept increasing in some regions. （2） A consistent decline in SO2 densities over areas around the coal-fired power plants, which might be brought by the flue gas desulfurization （FGD） system, did not appear. In contrast, the ascending trend of SO2 densities in some areas still existed even if the FGD was running. Correlation analysis of the SO2 density to year indicated that a single policy in power plants was limited for the SO2 emission reduction, because the policy＇s impact on the pollution in industrial underdeveloped regions was poor by far. （3） Bottom-up emission estimates of the coalfired power plants suggested that the SO2 emission reduction coming from the power plants has declined significantly since 2009. Consequently, more reasonable and sustainable emission reduction policies in Guizhou province, especially emission restrictions for other large emission sources, should be pushed out in the near future.