A Highly Resolved Anthropogenic Ammonia Emission Inventory In Guangdong Province And Assessment Of Control Strategies

In recent decades, with the rapid development of economy and accelerated urbanization,regional atmospheric hazy aerosol pollution have emerged in Guangdong Province frequently,which have caused the deterioration of air quality and visibility. Ammonia has two sides inatmospheric environment, including the neutralization of acid rain and influence of globalclimate change and atmospheric pollution directly or indirectly. Identification of ammoniaemission source and evaluation of ammonia emissions is of great importance and scientificsignificance to the regional atmospheric hazy aerosol pollution. For better understanding ofthe characteristics and trend of ammonia emission, temporal-spatial distributions, andidentification of key control strategies for agricultural ammonia emission sources, in thisstudy, we developed anthropogenic ammonia emission inventory for Guangdong Province,and studied agricultural ammonia emissions over the past decade. Besides, we assessed themitigation potentials of control strategies. This research is expected to provide scientificfoundations and evidence-based guidance for the improvement of regional air quality.Firstly, a2010-based anthropogenic ammonia emission inventory was developed forGuangdong Province based on the method of emission factors, and the total ammoniaemission was563kt. The most important contributor was agricultural source, accounting forapproximately84.1%of total anthropogenic emission. For livestock, hog emission constitutedthe largest proportion, accounting for53.2%of total livestock emission, followed by broiler,sow and yellow cattle. Zhanjiang, Maoming and Zhaoqing were the top three cities of largestammonia emissions, and conversely Zhuhai contributed the lowest emission in GuangdongProvince. The emission results were comparable and reasonable by contrasting with similaremission inventories as well as using qualitative and quantitative uncertainty analysis with thetool of AuvToolPro. Uncertainty in agricultural ammonia emission was relatively low with therelative error of41%to61%, and there were remarkable space for the improvement of theestimation of non-agricultural ammonia emissions.Secondly, a temporal and spatial ammonia emission inventory with a resolution of3km3km for Guangdong Province was developed by using empirical mathematical formula andArcGIS technology. Agricultural ammonia emission was associated with environmental conditions and the farming work, and it showed an obvious seasonal variation characteristic.The largest agricultural emission was in summer and every day at2p.m.. Meanwhile,anthropogenic ammonia emission mainly concentrated in the outer zone of GuangdongProvince, showing the pattern of high emission in west and low in east, and high emission inthe north and low in the south. Among these, Zhanjiang, Maoming and Zhaoqing were the topthree cities of ammonia emission, meanwhile ammonia emission of Heyuan, Shaoguan,Chaozhou, Dongguan, Zhongshan and Zhuhai were relatively less. The agricultural ammoniaemissions had a larger influence on the total spatial emission characteristic.Thirdly, the emission trend of agricultural ammonia from2000-2010was characterizedfor Guangdong Province based on statistical data in the last decade, considering with theagricultural structure and the level of development. The agricultural ammonia emissionsremained at higher levels in nearly a decade with an upward trend from2000to2010, exceptdescended in2007. Zhanjiang, Maoming and Zhaoqing had been the top three cities ofagricultural ammonia emission in Guangdong Province.Finally, based on the agricultural ammonia emission characteristics and trend, andcombined with the existing control levels and planning, the suggestions of agriculturalammonia emission control measures were made by assessing emission reductions with themethodology in GAINS model under different control scenarios. The results show that theagricultural ammonia emissions of Guangdong Province will continue to increase in the future.Although, the emission can be controlled in a certain extent under the current state of controllevel, but still beyond the emissions in2010. Therefore, further tightened control measuresshould be conducted to improve the ammonia emission situation in the atmosphere.