Establishment And Characteristic Analysis Of Atmospheric Ammonia Emission Inventory In The Yangtze River Delta

As the only alkaline gas in the atmosphere,ammonia has direct or indirect effects on environmental pollution,human health and climate change.The research on ammonia emission inventory was carried out based on the available data,including the activity data and emission factors.This research further improved the ammonia emission inventory in the Yangtze River Delta region,and the methods and ideas can provide reference for other regions to carry out emission inventory.Firstly,the main sources of ammonia emission in the YRD were determined by combining the available information of emission sources and the classification characteristics of emission sources.The activity data and emission factors of each ammonia source were selected from the various statistical yearbooks,related literature and empirical formulas,respectively.Secondly,the ammonia emission inventories in the YRD from 2006 to 2014 were established based on the above activity data and emission factors.The results showed that the ammonia emissions in the YRD had not changed significantly from 2006 to 2014.Agricultural sources were the main sources of ammonia emissions in the YRD,accounting for more than 80%of the total emissions.Urea was the largest source of ammonia from nitrogen fertilizer application,and pork farming was the largest source of livestock in the YRD.Vehicle was calculated to be the fastest growing source of ammonia emissions in the YRD.Xuzhou,Yancheng and Nantong were the top three cities contributing to the emissions in the YRD,and Zhoushan has the smallest ammonia emission.In terms of emission intensity,the average emission intensity in the YRD in 2014 was 4.6t/km~2,only ammonia emission intensity of Zhejiang Province(except Jiaxing)lower than the average value.This study compared the results with those similar inventories,and analyzed the uncertainty of ammonia emission in the YRD in 2014.It showed that the results of this study were comparable and the establishment of ammonia emission inventory in the YRD was reasonable.At last,the 1 km×1 km gridded ammonia spatial distribution in the YRD in 2014 were constructed based on appropriate allocation factors and geographic information system(ArcGIS).The agricultural sources in the Yangtze River Delta showed the trend of"high emission in the north and low emission in the south".The ammonia emissions from agricultural sources were mainly distributed in Jiangsu,and the high-value areas appeared in Nantong.High-value grid of ammonia emission from non-agricultural sources occurred in Shanghai,Changzhou,Suzhou,Wuxi and some areas of Jiaxing.The monthly average emission changes were established based on the time distribution information of nitrogen fertilizer source from 2006 to 2014,the results showed that the ammonia emission of nitrogen fertilizer sources varied withe agricultural time and gradually increased after spring then reached the highest value in July.