Active thermokarst zones on permafrost territory and their deteсting on space images

Abstract

The relevance of the paper is caused by the need to develop methods of identifying and mapping the areas of active thermokarst processes on the permafrost territory, based on satellite images and geoinformation technologies in the context of assessing the accumulation of methane in thermokarst lakes, which are considered as the most active sources of methane emissions into the atmosphere in the Arctic and sub-Arctic regions in the global warming of recent decades. The main aim of the study is to develop methodical questions to identify areas of distribution of thermokarst lakes in permafrost and map their boundaries, based on remote sensing and GIS tools. Methods used in the study: remote sensing of the thermokarst lakes spatial structure, including the little-studied small lakes, using satellite images of middle and high spatial resolution; methods of geographic information systems for spatial and statistical analysis of satellite images of fields of thermokarst lakes in the frozen thermokarst landscapes. The results. The authors developed methodical questions and described the procedure of active thermokarst zones detection as the areas of the dissemination of thermokarst lakes in the frozen landscape and determination of the boundaries of these zones based on Landsat-8 images and Kanopus-V high resolution images. A collection of Landsat-8 and Kanopus-V images obtained in summer of 2013-2014 was also formed. Using the developed methodology, the authors defined the boundaries and developed the map of active thermokarst zones on the territory of the discontinuous permafrost of Western Siberia.

Keywords

• permafrost
• global warming
• thermokarst lakes
• geoinformation systems
• satellite images