To ensure the long-term service performance of infrastructure such as railways, highways, airports and oil pipelines built on permafrost slope wetland sites, it is imperative to systematically uncover the long-term heat-water - water changes of soil in slope wetlands environment under climate warming. More specifically, considering valuable field data from 2001 to 2019, the long-term heat and water changes in active layers of the slope wetland site along the Qinghai- Xizang Railway (QXR) are illustrated, the effect of thermosyphon measures in protecting the permafrost environment is evaluated, and the influences of climate warming and hydrological effects on the stability of slope wetland embankments are systematically discussed. The permafrost at the slope wetland site is rapidly degrading, demonstrating a reduction in active layer thickness of > 3.7 cm per year and a permafrost temperature warming of > 0.006 degrees C per year. The thermosiphon embankment developed by QXR has a specific cooling period; thus, to mitigate the long-term impacts of climate warming on the thermal stability of permafrost foundation, it is essential to implement strengthening measures for the thermosiphon embankment, such as adding a crushed-rock layer or sunshade board on the slope of thermosiphon embankment to creating a composite cooling embankment. Short-term seasonal groundwater seepage intensifies frost damage to the slope wetland embankment, while long-term seasonal supra-permafrost water and groundwater seepage exacerbates uneven transverse deformation of slope wetland embankment. Long-term climate warming and slope effects have altered the surface water and groundwater hydrological processes of slope wetlands, potentially leading to an increased occurrence of slope embankment instability. These results are crucial for improving our understanding of heat and water variation processes in the active layer of slope wetland sites located in permafrost regions and ensuring long-term service safety for the QXR.

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the permafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively serious degradation. Furthermore, from the angles of grassland coverage and biological production the variation characteristics of high-cold ecosystems in different representative regions and different geomorphologic units under different climatic conditions were quantitatively assessed. In the future, adopting effective measures to protect permafrost is of vital importance to maintaining the stability of permafrost engineering and alpine cold ecosystems in the plateau.