A comprehensive biomass burning emission inventory with high spatial and temporal resolution in China
Biomass burning injects many different gases and aerosols into the atmosphere that could have a harmful effect on air quality, climate, and human health. In this study, a comprehensive biomass burning emission inventory including domestic and in-field straw burning, firewood burning, livestock excre...
Main Authors: | , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2017-02-01
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Series: | Atmospheric Chemistry and Physics |
Online Access: | http://www.atmos-chem-phys.net/17/2839/2017/acp-17-2839-2017.pdf |
Summary: | Biomass burning injects many different gases and aerosols into the atmosphere
that could have a harmful effect on air quality, climate, and human health.
In this study, a comprehensive biomass burning emission inventory including
domestic and in-field straw burning, firewood burning, livestock excrement
burning, and forest and grassland fires is presented, which was developed for
mainland China in 2012 based on county-level activity data, satellite data,
and updated source-specific emission factors (EFs). The emission inventory
within a 1 × 1 km<sup>2</sup> grid was generated using geographical
information system (GIS) technology according to source-based spatial
surrogates. A range of key information related to emission estimation (e.g.
province-specific proportion of domestic and in-field straw burning, detailed
firewood burning quantities, uneven temporal distribution coefficient) was
obtained from field investigation, systematic combing of the latest research,
and regression analysis of statistical data. The established emission
inventory includes the major precursors of complex pollution, greenhouse
gases, and heavy metal released from biomass burning. The results show that
the emissions of SO<sub>2</sub>, NO<sub><i>x</i></sub>, PM<sub>10</sub>, PM<sub>2.5</sub>, NMVOC, NH<sub>3</sub>,
CO, EC, OC, CO<sub>2</sub>, CH<sub>4</sub>, and Hg in 2012 are 336.8 Gg, 990.7 Gg,
3728.3 Gg, 3526.7 Gg, 3474.2 Gg, 401.2 Gg, 34 380.4 Gg, 369.7 Gg,
1189.5 Gg, 675 299.0 Gg, 2092.4 Gg, and 4.12 Mg, respectively. Domestic
straw burning, in-field straw burning, and firewood burning are identified as
the dominant biomass burning sources. The largest contributing source is
different for various pollutants. Domestic straw burning is the largest
source of biomass burning emissions for all the pollutants considered, except
for NH<sub>3</sub>, EC (firewood), and NO<sub><i>x</i></sub> (in-field straw). Corn, rice, and
wheat represent the major crop straws. The combined emission of these three
straw types accounts for 80 % of the total straw-burned emissions for
each specific pollutant mentioned in this study. As for the straw burning
emission of various crops, corn straw burning has the largest contribution to
all of the pollutants considered, except for CH<sub>4</sub>; rice straw burning has
highest contribution to CH<sub>4</sub> and the second largest contribution to other
pollutants, except for SO<sub>2</sub>, OC, and Hg; wheat straw burning is the
second largest contributor to SO<sub>2</sub>, OC, and Hg and the third largest
contributor to other pollutants. Heilongjiang, Shandong, and Henan provinces
located in the north-eastern and central-southern regions of China have higher
emissions compared to other provinces in China. Gridded emissions, which were
obtained through spatial allocation based on the gridded rural population and
fire point data from emission inventories at county resolution, could better
represent the actual situation. High biomass burning emissions are
concentrated in the areas with more agricultural and rural activity. The
months of April, May, June, and October account for 65 % of emissions
from in-field crop residue burning, while, regarding EC, the emissions in
January, February, October, November, and December are relatively higher than
other months due to biomass domestic burning in heating season. There are
regional differences in the monthly variations of emissions due to the
diversity of main planted crops and climatic conditions. Furthermore,
PM<sub>2.5</sub> component results showed that OC, Cl<sup>−</sup>, EC, K<sup>+</sup>,
NH<sub>4</sub><sup>+</sup>, elemental K, and SO<sub>4</sub><sup>2−</sup> are the main PM<sub>2.5</sub> species,
accounting for 80 % of the total emissions. The species with relatively
high contribution to NMVOC emission include ethylene, propylene, toluene,
mp-xylene, and ethyl benzene, which are key species for the formation of
secondary air pollution. The detailed biomass burning emission inventory
developed by this study could provide useful information for air-quality
modelling and could support the development of appropriate pollution-control
strategies. |
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ISSN: | 1680-7316 1680-7324 |