Combined use of Optical and Sar Data for Thermokarst Terrain: A Case Stduy in Central Yakutia

Permafrost, accounting for a quarter of the northern hemisphere, is widely distributed in Central Yakutia. Since permafrost is very sensitive to the changing climate, it shows significant changes due to the repetition of freezing and thawing resulting in unstable landforms such as thermokarst lake, pingo, patterned ground, and other thermokarst landscapes. It is necessary to understand its dynamics and the response of permafrost to the cryogenic process. To obtain dense in-situ observations is challenging under harsh conditions, remote sensing is a useful technique that can be used to observe and analyze dynamics spatially and temporally from a local to global scale. In our study, we represent the effectiveness of using optical satellite images and Synthetic Aperture Radar (SAR) images to monitor dynamic changes over permafrost region focusing on changes of thermokarst lake area.