基于卫星遥感的东北三省露天秸秆焚烧及其排放研究

STUDY ON OPEN BURNING OF CROP RESIDUES AND ITS EMISSIONS OF PM_(2.5) IN NORTHEAST CHINA BASED ON SATELLITE REMOTE SENSING

[目的]为了解我国东北地区露天秸秆焚烧及其排放情况,为东北地区秸秆资源综合利用、环境质量改善提供依据。[方法]基于MODIS卫星数据、GFASv1排放清单数据及土地利用数据,采用上下文算法及空间统计方法对东北三省2015~2017年秸秆焚烧火点及PM_(2.5)排放时空分布特征进行了分析。[结果]东北三省秸秆焚烧主要集中在黑龙江省西南部和东北部、吉林省的中西部以及辽宁省中部地区;2015~2017年东北三省共计1.871 8万个露天秸秆焚烧火点,PM_(2.5)排放总量为17.3万t,火点最多的年份为2017年,排放量最大的年份为2015年,东北三省中黑龙江省火点最多,排放量最大,占比分别为71.9%和73.3%;东北地区年内各月秸秆焚烧火点及PM_(2.5)排放在春(3~4月)、秋(10~11月)两季最为明显,呈双峰分布,春季火点数及排放量多于秋季,且呈春季增加、秋季减少趋势。[结论]东北地区秸秆资源综合利用量有了一定的提高,秋季禁烧工作成效明显,春季秸秆禁烧工作有待加强。

By investigating open burning of crop residues and its emission of PM 2.5 in Northeast China,it can provide a base for the policy of crop residues recycling and improving the air quality in this region.Based on the Terra/Aqua MODIS data from NASA and emission inventory named GFAS(version 1)from ECMWF,also with the Land cover dataset,the numbers of fire point and the emission of PM 2.5 from 2015 to 2017 were calculated and the temporal-spatial distribution were analyzed in three provinces of Northeast China.The results showed that the fire points of open burning of crop residues were mainly distributed in the northeast and southwest of Heilongjiang province,the mid-west of Jilin province and also the middle of Liaoning province.There were 18 718 fire points in the whole three provinces of Northeast China from 2015 to 2017,and total emissions of PM2.5 was 173 000 t,of which Heilongjiang province accounted for about 71.9%and 73.3%respectively.The maximum of fire point number happened in 2015,but the maximum of emission of PM 2.5 happened in 2017.In a year,there were two peaks of fire points numbers and emissions of open burning of crop residues in the three province happened in spring(from March to April)and in the autumn(from October to November)with spring the maximum.There was also an increased trend in spring and a decreased trend in autumn from the year of 2015.The above results showed that there was a positive effect of crop residues recycling policy and the forbidden policy of open burning of crop residues in the autumn.The increased trend of open burning of crop residues in the spring in Northeast China should be paid more concern and the further forbidden policy should be carried on.