兰州市农牧业源氨排放清单及其时空分布特征

通过实地调研等方式获取农牧业源的活动水平,采用NARSES模型确定氮肥施用排放因子,其它排放因子通过文献调研确定,建立了2016年兰州市农牧业源氨排放清单,并进一步分析了农牧业源氨排放的时空分布特征. 2016年兰州市农牧业源大气氨排放量为9 356. 90 t;其中畜禽养殖源氨排放量7 584. 03 t,分担率81. 05%;永登县是氨排放量最大的区县,氨排放量为2 820. 59 t,分担率为30. 14%.在兰州市各区县氨排放量分担率中,畜牧业源氨排放的分担率在65. 83%～97. 38%之间;氮肥施用源的分担率在2. 27%～28. 66%之间.从空间分布来看,兰州市农牧业源氨排放主要集中在皋兰县西北部与中部、红古区东南部、七里河区东西两部与榆中县东部.从时间分布来看,畜牧业源氨排放主要集中在4～9月,氮肥施用源的氨排放主要集中在3～7月和9月,其它月份排放量相对较小.

Inventory and Spatiotemporal Distribution of Ammonia Emission from Agriculture and Animal Husbandry in Lanzhou City

After obtaining data on the activity of agriculture and animal husbandry by field investigation and from statistical data, an inventory of ammonia emission from agriculture and animal husbandry in Lanzhou was established based on literature investigation to determine the emission factors. The emission factor related to the application of nitrogen fertilizer was calculated using the NARSES model. The spatiotemporal distribution of the amount of ammonia emission was also analyzed. The total amount of ammonia emission from agriculture and animal husbandry was 9356.90 t. Among this emission, the amount from livestock and poultry was 7584.03 t, accounting for 81.05%. Yongdeng County was the region with the largest amount of ammonia emission, which was 2820.59 t, accounting for 30.14%. Considering the sharing rate of ammonia emissions in all districts and counties, the sharing rates of livestock and poultry were between 65.83% and 97.38%; and the sharing rates for nitrogen fertilizer application were between 2.27% and 28.66%. From the perspective of spatial distribution, the sources of ammonia emissions from agriculture and animal husbandry were mainly concentrated in the northwest and central parts of Gaolan County, the southeast of Honggu District, the east and west of Qilihe District, and the east of Yuzhong County. From the perspective of temporal distribution, the ammonia emissions from livestock and poultry were higher from April to September. The emission from nitrogen fertilizer application was higher from March to September, except in August.