Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 8, issue 5 | Copyright
Biogeosciences, 8, 1225-1235, 2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 23 May 2011

Research article | 23 May 2011

Quantifying methane emissions from rice paddies in Northeast China by integrating remote sensing mapping with a biogeochemical model

Y. Zhang1, Y. Y. Wang2, S. L. Su3, and C. S. Li4 Y. Zhang et al.
  • 1Research Center of Remote Sensing & Geoscience, Northeast Institute of Geography & Agroecology, Chinese Academy of Sciences, Changchun 130012, China
  • 2Research Center for Wetland Ecology and Environment, Northeast Institute of Geography & Agroecology, Chinese Academy of Sciences, Changchun 130012, China
  • 3College of Environmental & Resources Sciences, Zhejiang University, Hangzhou 310029, China
  • 4Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA

Abstract. 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.

Download & links
Publications Copernicus