乌鲁木齐市空气污染时空分布特征及其与气象因素相关分析

基于乌鲁木齐市7个检测站点实测数据(参照《环境空气质量标准》规定的6项常规监测污染物(PM_2.5、PM_10、SO_2、NO_2、CO、O_3)的24小时/8小时国家二级标准和AQI分级标准),对乌鲁木齐市2016年空气质量做变化趋势分析。结合乌鲁木齐市气象要素和城市发展数据对乌鲁木齐市空气质量影响因素做相关分析,然后利用层次分析法(AHP)对乌鲁木齐市环境空气污染时空分布特征的影响因素做评价分析。研究结果有:(1)乌鲁木齐市2016年1月,轻度污染天气占整月的3%、中度污染天气占26%、严重污染天气占32%、重度污染天气占39%;工业园区集中的米东区是乌鲁木齐市空气污染最严重的城区。(2)乌鲁木齐市的城区空气污染物因子和同期气象因素相关性显著;(3)重要污染物企业的空间分布对乌鲁木齐市空气污染空间分布起到绝对的影响作用。

Spatiotemporal distribution pattern of ambient air pollution and its correlation with meteorological factors in Urumqi

Background, aim, and scope With the rapid development of urbanization, characteristics of air pollution has changed from soot type to mixed mode in China. Urumqi was in the list of the 10 cities that reported the worst air quality during the first nine months in 2016, according to a report published by the Ministry of Environmental Protection. The study aimed at discovering the main influencing factors of the air pollution in Urumqi. Materials and methods Based on the daily air pollution levels (6 regular monitoring pollutants (PM_2.5, PM₁₀, SO₂, NO₂, CO, O₃) concentrations, and air quality index (AQI) classification standard) in January 2016 in Urumqi, analyzing temporal and spatial distribution of air pollution in Urumqi by GIS. Main materials including the concentrations of PM_2.5, PM₁₀, SO₂, NO₂, CO, O₃ (Xinjiang Department of Environmental Protection, http://124.117.235.202:8011/), meteorological factors (China Meteorological Administration, http://data.cma.cn/user/toLogin.html/), and Landsat 8 TM image of Urumqi (Geospatial Data Cloud, http://www.gscloud.cn/). Combing analytic hierarchy process (AHP) with land use classification and distribution of important pollutant enterprises, by correlation analysis of air pollution factors and meteorological factors to evaluate the influencing factors of air pollution distribution characteristics in Urumqi. Results The research showed that lightly polluted, moderately polluted, severely polluted, heavily polluted days accounted for 3%, 26%, 32%, 39% of the whole month in January 2016 respectively. Midong District was the most polluted area, there were significant correlations between air pollution factors and meteorological factors. Discussion This research studied the temporal and spatial distribution characteristics of air pollution in Urumqi and its correlation with meteorological factors. The coldest month (January) of Urumqi in 2016 was selected as the study period. Firstly, the temporal and spatial distribution of air pollutant factors and temporal variation of meteorological factors in Urumqi were analyzed. Secondly, correlation analysis was carried out on pollutants and meteorological factors, and it was found that meteorological factors had significant effects on air pollutant factors. Finally, the air pollution assessment model of Urumqi was constructed by AHP, and the relationship of air pollution with land use, important pollutant enterprises and meteorological factors in Urumqi was further analyzed. In the study, some impacts that leaded to special cases were ignored, for example, breeze and calm wind. Conclusions Land use (weighting coefficient was 0.0852), important pollutant enterprises (weighting coefficient was 0.7375) and meteorological factors (weighting coefficient was 0.1773) were the main influencing factors of air pollution in Urumqi. Recommendations and perspectives Pollutant discharge type should be considered when the government regulate the pollution emissions to deal with the air pollution.