Mapping Soil Carbon Dynamics and Permafrost Thaw Response to Abrupt Climate Change in the Usa River Basin, Russia

\nA computer-based map is considered a crucial foundational resource for conducting comprehensive carbon budget studies in northern latitudes. Detailed soil maps were created for the intensive study sites located in the forest-tundra and tundra regions using QuickBird 61 cm panchromatic and 2.4 m multispectral resolution satellite images, alongside a database containing morphological descriptions and analytical data from 153 soil profiles, long-term permafrost monitoring sites, and meteorological records. The results of GIS-analysis indicate that approximately 60% of all infrastructure is situated in areas with a "high risk" of permafrost degradation. These areas, defined as zones with isolated to discontinuous permafrost coverage ranging from 3% to 90% and ground temperatures ranging from 0 to -2 °C, are expected to experience significant thawing within the next few decades to a century. Long-term measurements taken at CALM (Circumpolar Active Layer Monitoring) sites in the region have shown a continuous increase in thaw depths, resulting in a lowering of the permafrost table. This trend poses significant challenges for permafrost engineering and highlights the need for long-term investments in arctic infrastructure that will yield returns over time. The database has been utilized to assess soil organic carbon stocks.\n