2015~2018年西北地区典型城市空气污染特征对比分析

Comparative Analysis of Air Pollution Characteristics of Typical Cities in Northwest China from 2015 to 2018

摘要: 为防治西北地区空气污染，运用统计学方法对比分析了2015~2018年西北地区西安、兰州、乌鲁木齐和银川四个典型城市空气污染特征。结果表明：(1) 随着纬度的降低，空气质量越来越差，西北地区的北部优于南部城市群，其中东南部最差；各市空气质量从优到劣排名为银川 > 兰州 > 西安 > 乌鲁木齐。(2) 4市的污染物主要是PM_2.5、PM₁₀，两者年均浓度呈正相关且具有相似的季节和年变化趋势。(3) 4市的首要污染物是PM_2.5、PM₁₀和O₃，在这4年时间序列中发现其他污染物成为首要污染物逐年上升。(4) 后向轨迹图统计分析结果表明距离地面高度500 m和1000 m的污染物轨迹线具有高度的一致性，相同度高于75%。大气污染物传输路径的轨迹线以东北和西南方向为主，而空气受到严重污染时污染物的来向复杂。

Abstract: In order to prevent and control the air pollution in northwest China, the air pollution characteristics of four typical cities in northwest China from 2015 to 2018 were compared and analyzed by statistical methods. The results show that: (1) With the decrease of latitude, the air quality is get-ting worse and worse, the northern part of northwest region is better than the southern city group and the southeast is the worst. The air quality of each city ranked Yinchuan > Lanzhou > Xi’an > Urumqi from good to bad. (2) The pollutants are mainly PM_2.5 and PM₁₀, the average annual con-centrations of which are positively correlated and have similar seasonal and annual trends. (3) The primary pollutants in the four cities are PM_2.5, PM₁₀ and O₃. It is found that other pollutants have become the primary pollutants in the four-year time series. (4) The statistical analysis results of the backward trajectory map show that the pollutant trajectory lines with a height of 500 m and 1000 m from the ground are highly consistent, with the same degree higher than 75%. The transport path of air pollutants is mainly in the northeast and southwest directions, and the direction of air pollutants is complicated when the air is seriously polluted.