基于生态修复的矿区气溶胶时空分布特征——以迁安矿区为例

Spatial and Temporal Distribution Characteristics of Aerosols in Mining Areas Based on Ecological Restoration:A Case of Qian'an Mining Area

以迁安矿区为研究区,利用MODIS的气溶胶产品MCD19A2和MOD04_3K,探究2015年和2020年的气溶胶光学厚度(AOD)、?ngstr9m(AE)指数和气溶胶类型的时空变异特征。结果表明:(1)与2015年相比,除2020年冬季以外,2020年AOD值明显降低;(2)与2015年相比,2020年西北部细颗粒物占比增多,东南部粗颗粒物占比增多,矿区AE指数存在明显季节特征,春季AE指数较小,大气污染物以粗颗粒污染物为主,夏季和秋季AE指数较大,大气污染物以细颗粒物为主;(3)AE指数的季节变化也存在明显的时空分布特征,与2015年相比,冬季东部AE指数明显降低,粗颗粒占比增大,春季区域内整体AE指数升高,粗颗粒占比减少,秋季北部AE指数明显升高,粗颗粒占比减少,夏季是全年AOD值和AE指数的高峰期,其原因可能是6月和7月秸秆燃烧产生了大量的细气溶胶颗粒;(4)矿区气溶胶主要由生物质燃烧或城市-工业型气溶胶和混合型气溶胶构成,与2015相比,2020年春季主要气溶胶类型发生较大改变,沙尘型气溶胶占比明显减少;(5)2015年至2020年期间开展的矿区生态修复工程明显改变了矿区大气气溶胶光学属性和类型,在一定程度上改善了迁安矿区的大气环境。

The aerosol products MCD19A2 and MOD04_3K from MODIS were used to explore the spatial and temporal variability characteristics of aerosol optical depth,Angstrom index and aerosol type in 2015 and 2020,by using the Qian'an mining area as the study area.The results are concluded as follows.(1)Compared with 2015,except for AOD in the winter of 2020,the AOD values in 2020 are significantly reduced.(2)Compared with 2015,the proportion of fine particulate matters in the northwest increases in 2020,and the proportion of coarse particulate matters in the southeast increases.The AE index of the mining area has obvious seasonal characteristics.The AE index in spring is small,and the atmospheric pollutants are mainly coarse particulate pollutants.The AE index in summer and autumn is large,and the atmospheric pollutants are mainly fine particulate matter.(3)The seasonal variation of AE index also has obvious spatial and temporal distribution characteristics.Compared with 2o15,the AE index in the eastern part of winter decreases significantly,and the proportion of coarse particles increases.In spring,the overall AE index increases,and the proportion of coarse particles decreases.The AE index in the northern part of autumn increases significantly,and the proportion of coarse particles decreases.Summer is the peak period of annual AOD value and AE index.The reason may be that a large number of fine aerosol particles are produced by straw burning in June and July.(4)The aerosols in the mining area are mainly composed of biomass burning or urban-industrial aerosols and mixed aerosols.Compared with 2015,the main aerosol types change greatly in the spring of 2020,and the proportion of dust aerosols decreases significantly.(5)The ecological restoration projects carried out in the mining area during 2015-2020 have significantly changed the optical properties and types of atmospheric aerosols in the mining area,and have improved the atmospheric environment of the Qian'an mining area to a certain extent.