基于GIS技术的1991—2000年中国农田化肥氮源一氧化二氮直接排放量估计

Estimation of chemical fertilizer N-induced direct N_2O emission from China agricultural fields in 1991-2000 based on GIS technology.

依据政府间气候变化专门委员会（IPCC）对农田N2O排放因子的定义,将气候和种植制度等N2O排放的主控因素引入到估算方法中,结合GIS技术估计了中国农田化肥氮导致的N2O直接排放量的空间分布和年际变异.结果表明,在1991—2000年间由于化肥投入量的增加,中国农田化学氮源N2O排放呈上升趋势.20世纪90年代的平均年排放量为204GgN2O-N,变幅为159-269GgN2O-N,排放量最高的年份出现在1998年,而1992年排放量为最低.估算结果的不确定性约为23%.受施氮量和降水的影响,N2O排放通量表现出明显的地区差异,东部较高。

Referring to the definition of agricultural field N2O emission factor by the Intergovernmental Panel on Climate Change, the main controlling factors climate and cropping system were in troduced to estimate the chemical fertilizer N-induced direct N2O emission from China agricultural fields in 1991-2000, and a spatial inventory with 10 km × 10 km resolution was developed by dint of GIS framework. The results indicated that there was an increasing trend in the annual direct N2O emission, due to the increasing input of chemical fertilizer N. The mean annual emission in 1990s was estimated to be 204 Gg N2O-N, ranging from 159 to 269 Gg N2O-N, and the lowest and the highest emission occurred in 1992 and 1998, respectively. The uncertainty of the estimation was quantified to be about 23%. The spatial distribution of N2O emission was characterized by higher flux in eastern China and lower flux in western China, which was mainly attributed to the application rate of chemical fertilizer N and precipitation.