Application of Landsat-7 satellite data and a DEM for the quantification of thermokarst-affected terrain types in the periglacial Lena?Anabar coastal lowland

Abstract

Extensive parts of Arctic permafrost-dominated lowlands were affected by large-scale permafrost degradation, mainly through Holocene thermokarst activity. The effect of thermokarst is nowadays observed in most periglacial lowlands of the Arctic. Since permafrost degradation is a consequence as well as a signifi cant factor of global climate change, it is necessary to develop effi cient methods for the quantifi cation of its past and current magnitude. We developed a procedure for the quantifi cation of periglacial lowland terrain types with a focus on degradation features and applied it to the Cape Mamontov Klyk area in the western Laptev Sea region. Our terrain classifi cation approach was based on a combination of geospatial datasets, including a supervised maximum likelihood classifi cation applied to Landsat-7 ETM+ data and digital elevation data. Thirteen fi nal terrain surface classes were extracted and subsequently characterized in terms of relevance to thermokarst and degradation of ice-rich deposits. 78 % of the investigated area was estimated to be affected by permafrost degradation. The overall classifi cation accuracy was 79 %. Thermokarst did not develop evenly on the coastal plain, as indicated by the increasingly dense coverage of thermokarst-related areas from south to north. This regionally focused procedure can be extended to other areas to provide the highly detailed periglacial terrain mapping capabilities currently lacking in global-scale permafrost datasets.

Spectral characterization of periglacial surfaces and geomorphological units in the Arctic Lena Delta using field spectrometry and remote sensing

“…The contour interval is 10 m. Generally, steep bluffs along river channels are poorly captured. Though not very useful for hydrological research, the DEMs from such topomaps are of sufficient quality for geomorphological mapping, as already described in Grosse et al (2006). Comparison with a highresolution Corona satellite image (22 June 1964, panchromatic, 2.5 m) also indicates reasonably good map qualities.…”

Spatial analyses of thermokarst lakes and basins in Yedoma landscapes of the Lena Delta

“…For the Yedoma region of the Bykovsky Peninsula, Grosse et al (2005) found that about 53 % of the area is affected by thermokarst. For the Lena-Anabar lowland, which is similar in geological composition to the Lena Delta study area with Ice Complex deposits underlain by fluvial sands, about 49 % of the area is covered with thermokarst landforms (Grosse et al, 2006). Kaplina (2009) points out two types of Yedoma territories in north Yakutian lowlands, where thermokarst has no potential to develop.…”

“…This is in the same range as results of previous remote-sensing-based studies that cover other portions of the Ice Complex accumulation plain in the Laptev Sea region. For the Bykovsky Peninsula east of the Lena Delta, Grosse et al (2005) calculated the area affected by thermokarst and thermal erosion to be more than 50 %; for the area of Cape Mamontov Klyk west of the Lena Delta, Grosse et al (2006) calculated the affected area to be 78 %.…”

Land cover classification of tundra environments in the Arctic Lena Delta based on Landsat 7 ETM+ data and its application for upscaling of methane emissions

“…Within the last 15 years, some studies on land cover classifications utilizing Landsat remote sensing data with different thematic focus have been conducted in Alaska and Canada (Ferguson, 1991;Gross et al, 1990;Joria & Jorgenson, 1996;Muller et al, 1999;Stow et al, 1998;Brook & Kenkel, 2002). Land cover classifications of Arctic areas in Russia are rare and most of them have been accomplished within the last years (Rees et al, 2003;Takeuchi et al, 2003;Virtanen et al, 2004;Grosse et al, 2006).…”