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| Titel |
Quantifying methane emissions from rice paddies in Northeast China by integrating remote sensing mapping with a biogeochemical model |
| VerfasserIn |
Y. Zhang, Y. Y. Wang, S. L. Su, C. S. Li |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 5 ; Nr. 8, no. 5 (2011-05-23), S.1225-1235 |
| Datensatznummer |
250005818
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| Publikation (Nr.) |
 copernicus.org/bg-8-1225-2011.pdf |
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| Zusammenfassung |
| The Sanjiang Plain located in Northeastern China is one of the major rice
producing regions in the country. However, differing from the majority rice
regions in Southern China, the Sanjinag Plain possesses a much cooler
climate. Could the rice paddies in this domain be an important source of
global methane? To answer this question, methane (CH4) emissions from
the region were calculated by integrating remote sensing mapping with a
process-based biogeochemistry model, Denitrification and Decomposition or
DNDC. To quantify regional CH4 emissions from the plain, the model was
first tested against a two-year dataset of CH4 fluxes measured at a
typical rice field within the domain. A sensitivity test was conducted to
find out the most sensitive factors affecting CH4 emissions in the
region. Based on the understanding gained from the validation and
sensitivity tests, a geographic information system (GIS) database was
constructed to hold the spatially differentiated input information to drive
DNDC for its regional simulations. The GIS database included a rice map
derived from the Landsat TM images acquired in 2006, which provided crucial
information about the spatial distribution of the rice fields within the
domain of 10.93 million ha. The modeled results showed that the total
1.44 million ha of rice paddies in the plain emitted 0.48–0.58 Tg CH4-C
in 2006 with spatially differentiated annual emission rates ranging between
38.6–943.9 kg CH4-C ha−1, which are comparable with that observed in
Southern China. The modeled data indicated that the high SOC contents, long
crop season and high rice biomass enhanced CH4 production in the cool
paddies. The modeled results proved that the northern wetland agroecosystems
could make important contributions to global greenhouse gas inventory. |
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