Estimation of CH_4 emission from Siberian natural wetland by land surface dynamics characterization with remote sensing

摘要

In this paper, snow cover changes from 2002 to 2012 and its relation to methane emissions were investigated in Siberian natural wetland. Firstly, globcover land-cover map for the essential data, which is a product of MERIS from ENVISAT, was used to mask out the wetland distribution. Secondly, timing and duration of snow and water coverage were investigated and their areal changes were calculated from 2002 to 2012. Using average, the most value and other threshold value to find out the natural phenomenon of snow and water coverage in each year. Thirdly, apply the model as the NDVI and land surface temperature (LST) function by image processing to get the daily methane flux. Finally, Snow and land surface water coverage (LSWC) behavior such as timing, duration and offset and onset date will be investigated from high confidence, valuable and density appearance of representative regions. Following the result of methane emission of one specific point in Siberia, in this study will estimate not only the water and snow coverage conditions as duration and timing dynamics, but also the methane flux in regional scale of natural wetland. As a result it was found that from 2001 to 2012, the total emissions of methane appear increasing tendency both is LST and NDVI function. As LST function, mean methane flux in July and August in 2003 are 3.53 (mg/m~2/day) and 3.37 (mg/m~2/day); 3.52 (mg/m~2/day) and 3.37 (mg/m~2/day) in 2010. As NDVI function, mean methane flux in July and August in 2003 are 3.37 (mg/m /day) and 3.367 (mg/m~2/day); 3.37 (mg/m~2/day) and 3.34 (mg/m~2/day) in 2010.