福建省地级市人为源活性氮排放及其特征分析

在人口增长和快速城市化的背景下,活性氮排放对生态环境的影响日益加剧.为研究省级尺度活性氮排放规律,采用排放因子法建立2000、2005及2010年福建省人为源活性氮排放清单,分析各地市3个年份活性氮排放量及排放强度特征.结果表明,3个年份福建省活性氮排放总量分别为538.4、587.0和619.97 Gg,呈整体增加趋势.在9个地级市中,增速最快的为莆田市,而漳州市排放量有所下降.排放量最大的为漳州和泉州,排放量最小的为宁德与厦门.从排放来源看,90%以上的排放来自农田生态系统和畜禽养殖系统.能源活动贡献较小,但其排放增长最为显著.2010年,各地市单位面积活性氮排放强度呈"东南沿海高西北内陆低"的格局,最高为厦门市,最低为三明市;GDP和人口排放强度则呈"东南沿海低西北内陆高"的格局,最高为南平市,最低为厦门市.在分析各地市活性氮排放源特征的基础上,探讨了不同地区活性氮减排重点,研究结果可为福建省及下辖各地市活性氮减排提供科学依据.

Analysis of Anthropogenic Reactive Nitrogen Emissions and Its Features on a Prefecture-level City in Fujian Province

The impacts of reactive nitrogen (Nr) on the environment significantly increase with population and rapid urbanization. In order to study gaseous Nr and Nr loads to waterbodies at the provincial scale, we established anthropogenic emission inventories in prefecture-level cities in Fujian Province and analyzed the changes in Nr emissions for the years 2000, 2005, and 2010. The total Nr emissions were calculated as 538.4, 587.0, and 620.0 Gg in those three years, respectively. The emissions of Nr increased in nine prefecture-level cities except in Zhangzhou. Among these nine cities, Putian is the fastest growing one. The largest emitters were Zhangzhou and Quanzhou, while Ningde and Xiamen were the smallest ones. Agricultural ecosystems and livestock were the main sources of Nr emissions, both of them accounting for more than 90% of total anthropogenic Nr emissions. Despite rapid growth, energy activities had a minor contribution to total Nr emissions. The per area Nr emissions of each prefecture-level city were highest in Xiamen in the southeast coastal area and lowest in Sanming located in the northwest inland region in 2010. However, the patterns of GDP, population, and emission intensities showed the opposite trends to per area Nr emissions, lowest in Xiamen and highest in Nanping. We further discussed the significance of Nr emissions reductions in different areas based on the analysis of the characteristics of Nr emission sources in prefecture-level cities. The results provide a scientific basis for reducing Nr emissions in Fujian Province and its prefecture-level cities.