2015-2017年中国臭氧浓度时空变化特征

Spatial and Temporal Variations of Ozone Concentration in China during 2015-2017

选取中国366个城市作为研究区域,采用空间自相关方法,分析了2015-2017年中国主要城市近地面臭氧浓度的时空分布特征。研究发现:全国范围内臭氧污染呈逐年加重趋势,污染严重地区主要集中在我国中东部,且有南移的趋向,4-9月为臭氧浓度高值期,春、夏两季臭氧浓度较高,秋、冬两季的较低。臭氧污染具有明显的时空分异,春、夏污染较为严重,春季污染区域主要分布在我国的中东部,夏季则进一步向西部地区扩散,秋季情况有所好转,污染分布区域逐渐收缩,冬季基本不发生污染。O3浓度具有明显的空间集聚态势,热点主要集中在东北南部、华北、华东北部和华中北部,冷点则主要集中在华南、西南、华中南部及东北北部。在季节上也呈现出空间集聚态势,春、夏两季冷、热点分布状况与全年的大致相同,秋季热点西收南扩,冷点地区则逐渐向西部集中,冬季冷热点分布情况则与春、夏的相反。

High-concentration ozone(O3)near the surface has a detrimental effect on plant growth,which will lead to crop yield reduction and serious damage to national food security.This paper selects 366 cities in China as research areas,and uses spatial autocorrelation method to analyze the spatial and temporal distribution characteristics of the near-surface O3 concentration in major cities in China from 2015 to 2017.The results show that the ozone pollution in China tends to increase year by year.The heavily polluted areas are mainly concentrated in the central and eastern parts of China,and there is a trend of southward shift.From April to September,O3 concentration is high.Seasonally,O3 concentration is higher in spring and summer,but lower in autumn and winter.The O3 pollution has obvious spatial-temporal differentiation characteristics.The pollution in spring and summer is more serious.The spring pollution area is mainly distributed in the central and eastern parts of China,but in summer it spreads further to the western part.Then in autumn the situation is improved,and the pollution distribution area gradually contracts.There is no ozone pollution in winter.In addition,the O3 concentration has an obvious spatial agglomeration trend.The hotspots are mainly in the south of Northeast China,North China,Northeast China and the north of Central China,while the cold spots are mainly in South China,Southwest China,south of Central China and north of Northeast China.In seasons,O3 pollution also shows a spatial agglomeration trend.The distribution of cold hotspots in spring and summer is almost the same as that of the whole year.The hotspots in the autumn contract to the west but expand to the south of China.In contrast,the cold spots gradually concentrate towards the west of China.The distributions of cold and hot spots in winter are opposite to the situation in spring and summer.