The Analysis of Variation Characteristics of Air Pollution and Influential Factors during the Eleventh Five-Year Plan in Urumqi City

In order to understand the air pollution changing characteristics and influential factors during the Eleventh Five-Year Plan in Urumqi City and to evaluate the effect of air pollution control and meteorological factors,the air pollution changing characteristics as well as its causes of pollutant emission and meteorological factor were studied for the Eleventh Five-Year Plan Period using daily atmospheric monitoring data from 2001 to 2010. The result showed that the average concentrations of SO2and PM10during the Eleventh Five-Year in Urumqi City decreased by 1. 7% and10. 3% respectively compared to the Tenth Five-Year Plan,especially the decrease in heating season were up to 2. 2% and 21. 9% respectively. Nevertheless the concentration of NO2 increased by 8. 9% in the same period,especially in non-heating season when it was highest. The annual average concentrations of PM10and SO2decreased as a whole from 2006 to 2010,but the concentration of NO2showed increase from 2006 to 2010. The concentrations of main air pollutants in non-heating season could meet the National Ambient Air Quality Standard Ⅱ,but its concentrations have all increased continuously. Furthermore the exceeding standard multiples of SO2and PM10in the heating season have decreased yearly. The coal smoke pollution in heating season was still very typical. Pollution source control especially pollutants emission reduction project was the key factors for the decline of the concentrations of SO2and PM10during the Eleventh Five-Year Plan,while the meteorological factors had little contribution to the decrease of pollutants concentration. The increase of NO2concentration during the same term was due to the increase of vehicle number and the lagging of NOxemission control.