四川盆地大气污染物质量浓度时空变化特征

Temporal and Spatial Variation Characteristics of Air Pollutant Mass Concentration in Sichuan Basin

为了从数据层面揭示近几年四川盆地空气污染的现状以及变化规律,利用2015-2020年6种污染物(PM_(2.5)、PM_(10)、CO、NO_(2)、SO_(2)、O_(3))质量浓度数据,对四川盆地污染物浓度的时空变化进行分析,得到了四川盆地近6年空气污染的变化情况。研究结果:(1)CO浓度逐年降低,空间分布表现为东高西低;NO_(2)浓度先增高后降低,存在两个高值中心分别为成都和重庆西南部;SO_(2)浓度逐年降低,空间分布北低南高。(2)对于冬季颗粒物浓度,川东北逐年下降,成都平原先升高后降低,川南地区呈降低趋势。盆地PM_(2.5)/PM_(10)比值的年均值高于62%,6年来比值有所升高,自贡、乐山、宜宾一带为PM_(2.5)/PM_(10)比值高值区。(3)夏季O3浓度6年内先升高后降低,成都平原浓度值最高,川南次之,川东北最低。

In order to reveal the current situation and change law of air pollution in the Sichuan Basin in recent years from the data level,using the mass concentration data of six kinds of pollutants(PM_(2.5),PM_(10),CO,NO_(2),SO_(2),O_(3))from 2015 to 2020,the spatial and temporal changes of the concentration of pollutants were analyzed,and the changes of air pollution in the Sichuan Basin in the past six years were obtained.The results of the study are as follows:(1)The concentration of CO decreased year by year,and the spatial distribution was high in the east and low in the west;the concentration of NO_(2) increased at first and then decreased,and there were two high-value centers in Chengdu and southwestern Chongqing;the concentration of SO_(2) decreased year by year,and the spatial distribution was low in the north and high in the south.(2)As for the concentration of particulate matter in winter,the northeast Sichuan decreased year by year,the Chengdu Plain at first increased and then decreased,and the south Sichuan showed a decreasing trend.The annual average value of PM_(2.5)/PM_(10) ratio in the basin is higher than 62%,and the ratio has increased in the past six years.ZiGong,LeShan,and YiBin are the areas with high PM_(2.5)/PM_(10) ratio.(3)The concentration of O_(3) in summer first increased and then decreased within six years,with the highest concentration in Chengdu Plain,followed by southern Sichuan,and the lowest in northeastern Sichuan.