The history of permafrost landscape map compilation is related to the study of ecological problems with permafrost. Permafrost-landscape studies are now widely used in geocryological mapping. Permafrost-landscape classifications and mapping are necessary for studying the trends in development of the natural environment in northern and high-altitude permafrost regions. The cryogenic factor in the permafrost zone plays a leading role in the differentiation of landscapes, so it must be considered during classification construction. In this study, a map’s special content was developed using publications about Yakutian nature, archive sources from academic institutes, the interpretation of satellite images, and special field studies. Overlays of 20 types of terrain, identified by geological and geomorphological features, and 36 types of plant groupings, allowed the systematization of permafrost temperature and active layer thickness in 145 landscape units with relatively homogeneous permafrost-landscape conditions in the Sakha (Yakutia) Republic. This map serves as a basis for applied thematic maps related to the assessment and forecast of permafrost changes during climate warming and anthropogenic impacts.

The purpose of this article was to compile four separate digital thematic maps of temperature and ice content of permafrost, the active layer thickness, and cryogenic processes in Yakutia as a basis for assessing changes to modern climate changes and anthropogenic disturbances. In this work, materials on permafrost were used, serving as the basis for compiling a permafrost landscape map of the Republic of Sakha (Yakutia). The maps were compiled using ArcGIS software, which supports attribute table mapping. The ground temperature and active layer thickness maps reflected landscape zonality and regional differences. Peculiarities of genetic types of Quaternary deposits and climatic conditions reflected the ice content of surface sediments and cryogenic process distribution maps. One of the most common is ground temperatures from −2.1 to −4.0 °C, which were found to occupy about 37.4% of the territory of Yakutia. More than half of the region was found to be occupied by permafrost landscapes with a limited thickness of the active layer up to 1.1 m. Ice-rich permafrost (more than 0.4 in ice content) was found to be typical for about 40% of the territory. Thermokarst is the most hazardous process that occurs in half of Yakutia.

In the last two decades in Central Yakutia, there has been a significant change in cryogenic landscapes related to climate warming and anthropogenic disturbances. This period is characterized by the activity of forest fires, which significantly impact permafrost landscapes. We observed the dynamics of cryogenic landscapes after a forest fire in 2001 at the Neleger station in Central Yakutia, 35 km northwest of Yakutsk. The observations included ground temperature and active layer thickness monitoring and statements of changes in the soil moisture content of the active layer. Increases in ground temperature, the active layer thickness, and soil moisture content on the burnt site after a forest fire in Neleger station were noted in the first six to seven years after the disturbance. We found that, following forest fires, permafrost progressively restabilizes as forest cover redevelops over time. The results of the studies will become the basis for planning restoration work after forest fires in permafrost landscapes of Central Yakutia.

This paper presents the results of 30 years of permafrost thermal monitoring in the Tiksi area in the eastern Russian Arctic. At a stone ridge site, the mean annual temperatures in the upper 30 m of the ground have increased by 1–2.4 °C compared to the first years of observations, with trends of °C/yr. At the same time, its change was uneven. In the last 20 years, the rate of increase has increased compared with the first decade of observations. At wet tundra sites in the foothill plain, the mean annual temperatures at the top of permafrost have increased by 2.4–2.6 °C between 2005 and 2022 at rates of 0.11–0.15 °C/yr, and the active layer thicknesses have increased at rates of 0.05–0.41 cm/yr.

Arctic regions are highly impacted by the global temperature rising and its consequences and influences on the thermo-hydro processes and their feedbacks. Theses processes are especially not very well understood in the context of river–permafrost interactions and permafrost degradation. This paper focuses on the thermal characterization of a river–valley system in a continuous permafrost area (Syrdakh, Yakutia, Eastern Siberia) that is subject to intense thawing, with major consequences on water resources and quality. We investigated this Yakutian area through two transects crossing the river using classical tools such as in–situ temperature measurements, direct active layer thickness estimations, unscrewed aerial vehicle (UAV) imagery, heat transfer numerical experiments, Ground-Penetrating Radar (GPR), and Electrical Resistivity Tomography (ERT). Of these two transects, one was closely investigated with a long-term temperature time series from 2012 to 2018, while both of them were surveyed by geophysical and UAV data acquisition in 2017 and 2018. Thermodynamical numerical simulations were run based on the long-term temperature series and are in agreement with river thermal influence on permafrost and active layer extensions retrieved from GPR and ERT profiles. An electrical resistivity-temperature relationship highlights the predominant role of water in such a complicated system and paves the way to coupled thermo-hydro-geophysical modeling for understanding permafrost–river system evolution.

Permafrost lies close to the surface of the day, therefore, it is able to quickly respond to modern climatic changes. Under these conditions, the goal of understanding the evolution of permafrost in the near future requires monitoring studies of the current state of permafrost and, first of all, its thermal conditions. In this work, based on the experience of many years of research at the Melnikov Permafrost Institute of Siberian Branch of the Russian Academy of Science (MPI SB RAS), methodological and technical issues of equipping experimental sites for monitoring the thermal state of permafrost in Eastern Siberia are considered. It is demonstrated that the reliability of permafrost thermal monitoring depends not only on measurement devices used but also on proper borehole system design and adequate choice of a method for active-layer thickness measurement depending on soil composition and properties. The use of protective tubes significantly lengthens the life of sensors in soils. A method of protecting the loggers from surface waters is recommended.