The Lena Delta, situated in Northern Siberia, is the largest arctic delta. Since natural deltas are characterised by complex geomorphological patterns and ecosystems, high-resolution information on the distribution and extent of the delta environments is necessary for an accurate spatial quantification of biogeochemical processes as the emission of greenhouse gases from tundra soils. In this study, the first land cover classification for the entire Lena Delta based on Landsat 7 ETM+ images was conducted and used for the quantification of methane emissions from the delta ecosystems on the regional scale. Nine land cover classes of aquatic and terrestrial ecosystems in the clearly wetland dominated Lena Delta could be defined by this classification approach. The use of the high resolution land cover maps reduces considerably the error potential of the regional upscaling of methane emissions.