连云港市大气降尘时空分布特征

采用2018年1月—2020年2月连云港市17个监测点位降尘数据,分析连云港市大气降尘变化规律和时空分布特征。结果表明,2018年连云港市平均降尘量为11.6 t/(km 2·30 d),超过江苏省考核标准6 t/(km 2·30 d)],超标倍数为0.93,其呈现出先增大再降低再增大的规律,春季、秋季降尘量最大,与大风、干燥天气有关;除了8月,其他月份县区降尘量均高于市区;市区降尘量变化比较平稳,县区下半年变化幅度比较大。各监测点降尘分布存在明显差异,市环境监测站、胡沟管理处、德源药业、矿山设计院4个监测点的降尘量与PM 2.5及PM 10相关性较高,说明降尘与PM 2.5及PM 10的来源具有一致性。2019年降尘量明显降低且差异略小,除了春季(3和4月)超标,其他季节均达标。

Temporal and Spatial Distribution Characteristics of Atmospheric Dust fall in Lianyungang City

Based on dust-fall data of 17 monitoring sites from January 2018 to February 2020 in Lianyungang City,temporal and spatial distribution characteristics of atmospheric dust-fall were researched.The results showed that the average amount of dust-fall in Lianyungang was 11.6 t/(km 2·30 d)in 2018,which exceeded the assessment standard of Jiangsu Province6 t/(km 2·30 d)].The exceeding multiple was 0.93.The average amount of dust-fall first increased,then decreased,and then increased again.The highest amount of dust-fall in spring and autumn were related to strong wind and dry weather.Except for August,the dust-fall in the county area was higher than that in the urban area.The change of dust-fall amount in urban area was relatively stable,while the change of county area was relatively large in the second half of a year.The distribution of dust-fall in each monitoring site was obviously different.There was high significant correlation between the dust-fall and the mass concentration of PM 2.5 and PM 10 at four monitoring sites,including Lianyungang Environmental Monitoring Center,Hugou Management Office,Deyuan Pharmaceutical Co.,Ltd and Bluestar Lehigh Engineering institute Co.,Ltd.,it indicated that the dust-fall was consistent with the source of PM 2.5 and PM 10.The amount of dust-fall in 2019 reduced apparently,which reached the standard except in spring(March and April),and the difference of distribution characteristics decreased.