基于MODIS影像内蒙古草地火排放污染物动态研究

运用自主设计生物质燃烧系统，测定草本燃烧排放因子，基于MODIS火点数据，运用排放因子法对内蒙古区域2000~2017年草本燃烧排放污染物时空格局进行分析.结果表明，狼尾草、芦苇、拂子茅和狗尾草CO₂、CO、NO_x、C_xH_y、PM_2.5、TC、OC和EC排放因子范围为1402.6~1550.1，140.3~253.8，0.67~1.55，21.5~93.7，3.74~6.89，1.66~3.06，1.42~2.71和0.23~0.44g/kg；区域生物质密度时空分布不均匀，地上生物质密度总体呈东北向西南递减趋势.草地总燃烧生物量为8061.46kt，排放各污染物CO₂、CO、NO_x、C_xH_y、PM_2.5、TC、OC和EC总量分别为：11296.13，1609.79，10.80，408.96，44.50，20.06，17.23，2.83kt；共发生49374次草地火，火面积和火点密度从东北向西南逐渐递减，月变化呈双峰分布，主峰火点（3月）显著高于次峰（9月）.

Dynamic changes of pollutants emission from grassland fires based on MODIS images in Inner Mongolia

A self-designed biomass combustion system was used to measure the emission factors of grassland burning based on the MODIS image data of Inner Mongolia zone and the temporal and spatial patterns of pollutants emitted from burning of grassland from 2000 to 2017 were analyzed. The results showed that the average emission factors of CO₂, CO, NO_x, C_xH_y, PM_2.5, TC, OC and EC from the burning of Phragmites communis, Setaria viridis, Pennisetum alopecuroides and Calamagrostis epigeiosare were 1402.6~1550.1, 140.3~253.8, 0.67~1.55, 21.5~93.7, 3.74~6.89, 1.66~3.06, 1.42~2.71, 0.23~0.44g/kg, respectively. Inner Mongolia grassland biomass density had uneven spatial and temporal distribution and the distribution of biomass density had gradually decreasing from northeast to southwest. The total biomass burnt was 8061.46kt, and the total amounts of the emitted CO₂, CO, NO_x, C_xH_y, PM_2.5, TC, OC and EC were 11296.13 kt, 1609.79 kt, 10.80 kt, 408.96 kt, 44.50 kt, 20.06 kt, 17.23 kt and 2.83 kt, respectively. A total of 49,374 grassland fires had occurred, with the fire points and fire areas were unbalanced in time and space. The monthly variation exhibited a bi-modal distribution, the main-peak fire point (March) was significantly higher than the secondary-peak fire point (September), and the distribution of fire density and fire area had a gradually decreasing trend from northeast to southwest.