Current status and future trends of SO2 and NOx pollution during the 12th FYP period in Guiyang city of China

In order to investigate the future trends of SO2 and NOx pollution in Guiyang city of China, the MM5/CALMET/CALPUFF modeling system is applied to assess the effects of air pollution improvement that would result from reduction targets for SO2 and NOx emissions during the 12th Five-Year Plan (2011–2015). Three scenarios are established for the objective year 2015 based on the reference emissions in base year 2010. Scenario analysis and modeling results show that emissions are projected to increase by 26.5% for SO2 and 138.0% for NOx in 2015 Business-As-Usual (BAU) relative to base year 2010, respectively, which will lead to a substantial worsening tendency of SO2 and NOx pollution. In comparison, both the 2015 Policy Reduction (PR) and 2015 Intensive Policy Reduction (IPR) scenarios would contribute to improve the urban air quality. Under 2015 PR scenario, the maximum annual average concentration of SO2 and NOx will reduce by 54.9% and 31.7%, respectively, relative to the year 2010, with only 2.1% of all individual gridded receptors exceed the national air quality standard limits; while the maximum annual average concentrations of SO2 and NOx can reduce further under 2015 IPR scenario and comply well with standards limits. In view of the technical feasibility and cost-effectiveness, the emission reduction targets set in the 2015 PR scenario are regarded as more reasonable in order to further improve the air quality in Guiyang during the 12th FYP period and a series of comprehensive countermeasures should be effectively implemented.