Permafrost areas are sensitive to climate change and have a significant impact on energy and water cycles. Ground ice is a crucial component on the Qinghai–Tibetan Plateau (QTP). Understanding the environmental characteristics of ground ice is vital for accurately modeling its distribution and evolution. In this study, we analyzed 15 environmental characteristics of high ice-content permafrost sites. These attributes were extracted from 400 high ice-content permafrost datasets including 300 drilling boreholes and 100 thaw slumps collected throughout the entire plateau using large-scale remote sensing data and their products. The results are as follows: The mean annual air temperature in areas where high ice-content permafrost exists ranges from −5 to −3.5 °C, with an average warming rate of 0.08 °C/a. Additionally, there was an average increase in precipitation of about 25 mm/10a and an increase in soil moisture of about 4%/10a. Geomorphology strongly influences the occurrence of high ice content permafrost, with 85% of high ice-content permafrost development at altitudes between 4400 and 5100 m. Approximately 86% of high ice-content permafrost were developed in lowland or relatively flat areas, preferably in gently sloping and shady slope regions. Soils exhibit less variability in clay particles and more variability in silt and sand. Key indicators in the high ice content permafrost region include warming rate, active layer thickness, elevation, bulk density, soil thickness, clay content, precipitation, soil moisture, and NDVI. High ice-content permafrost is the result of a combination of environmental factors and is expected to undergo significant changes in the future. This study provides a foundation for comprehending the environmental changes in the high ice-content permafrost areas and modeling the distribution of ground ice. It underscores the urgent need to address the significant environmental changes faced by high ice-content permafrost regions.

The lakes distributed in permafrost areas on the Tibetan Plateau (TP) have been experiencing significant changes during the past few decades as a result of the climate warming and regional wetting. In September 2011, an outburst occurred on an endorheic lake (Zonag Lake) in the interior of the TP, which caused the spatial expansion of three downstream lakes (Kusai Lake, Haidingnor Lake and Salt Lake) and modified the four independent lake catchments to one basin. In this study, we investigate the changes in surficial areas and water volumes of the outburst lake and related downstream water bodies 10 years after the outburst. Based on the meteorological and satellite data, the reasons for the expansion of downstream lakes were analyzed. Additionally, the importance of the permafrost layer in determining hydrological process on the TP and the influence of from lake expansion on engineering infrastructures were discussed. The results in this study showed the downstream lakes increased both in area and volume after the outburst of the headwater. Meanwhile, we hope to provide a reference about surface water changes and permafrost degradation for the management of lake overflow and flood on the TP in the background of climate warming and wetting.

Changes of the lakes on high-altitude regions of the Tibet Plateau influence the state of the surrounding permafrost. Due to the climate warming and wetting trend, extreme events including lake outburst has occurred more frequent. In 2011, an outburst event occurred on the Zonag Lake and this event changed the water distribution in the basin, leading a rapid expansion of the Tailwater lake, named as the Salt Lake. However, the construction of the drainage channel in the Salt Lake ended the expansion process and the shrinkage of the lake started since 2020. To investigate the permafrost state around the Salt Lake, multiple methods, including drilling boreholes, the unmanned aerial vehicle survey and the ground penetrating radar detection have been applied. By integrating these multi-source data, the thermal regime, topography and the spatial distribution of the permafrost around the Salt Lake were analyzed. The result showed that the permafrost state around the Salt Lake was related to the distance from the lake water. The permafrost table appears at 90 m away from the Salt Lake and interrupted by a nearby thermokarst lake at 220 m. The ground temperature in the natural field is 0.2 °C lower than the temperature in the lake at a depth of −5 m.

In permafrost regions, construction of a channel involves a large amount of excavation activities and changes to surface water body, which can exert great impacts on the thermal regimes of permafrost underlying. In this paper, a coupled mathematical model of heat and moisture transfer was constructed for freeze‐thaw soils to investigate the long‐term thermal regimes of subgrade beneath a drainage channel built on the Qinghai‐Tibet Plateau. Based on the numerical simulations, the thermal regimes of the subgrade both in warm and cold seasons were analyzed within a period of 50 years, as well as the impact of the widths of the channel. The results showed that the channel excavation and flowing water within could lead to a significant underlying permafrost degradation. During the first 30 years, the permafrost beneath the channel mainly experienced a rapid downward degradation. After that, the lateral thermal erosion of the flowing water led to a rapid permafrost degradation beneath the slope of the channel. In cold seasons, the shallow ground beneath the channel would not refreeze due to the flowing water and the thaw bulb actually expanded throughout the year. For the channel with a bottom width of 15 m, the thaw bulb beneath the channel could expand laterally to the natural ground about 10 m far away from the slope shoulder of channel till the 50th year. With different widths, the long‐term thermal regimes of the subgrade beneath the channels differed considerably and the maximum difference was at the slope toe of the embankment. With the numerical simulated results, it is recommended that a channel built on permafrost should be wide‐and‐shallow rather than narrow‐and‐deep if conditions permit.

In the context of climate warming and the frequent wind‐sand hazards in the Qinghai‐Tibet Engineering Corridor (QTEC), the construction of the embankment will affect the thermal regime of permafrost underground. The influence of embankment construction on the variation of the permafrost table beneath it is different, especially for the regime with different mean annual ground temperatures (MAGTs). In this study, the effects of the unilateral sand particles deposition on the spatial distribution and temporal evolution pattern of temperature beneath the embankment are investigated through the numerical simulations, in which the heat transfer is considered. The model is validated by the field observed data of soil temperatures around an experimental zone built at the sand hazard area in Honglianghe, the interior of Qinghai‐Tibet Plateau (QTP). The simulated results indicate that the temperature field beneath the embankment is asymmetrically distributed under the condition of unilateral sand particles deposition. This asymmetry gradually weakened with the increase of operation time and the gradual adjustment of the permafrost temperature field. By comparing the permafrost table beneath the natural surface, the sand deposition center, and the middle of the embankment center, it could be found that the unilateral sand particles deposition has less effect on the degradation of the permafrost table in the center of the embankment. However, for the center of the sand deposition, the change of the permafrost table is larger with the increase of time and the corresponding rate of permafrost table degradation is higher than that without sand particles deposition, especially for the high‐temperature permafrost. In addition, with different sand thickness and width conditions, the effect of “narrow‐thick” form sand particles deposition on the temperature field beneath embankment is greater than that of “wide‐thin” form sand deposition. Hence, in order to reduce its impact on the long‐term thermal condition beneath the embankment, it is necessary to clean the thicker deposition sand particles at the toe of the embankment.