In recent years, global climate warming has significantly affected slope stability in permafrost regions, increasing landslide risk. Current research primarily focuses on single types of landslides, such as thaw-induced slumps, but lacks in-depth studies on elevation-dependent landslide characteristics and their relation to permafrost degradation.

A research team led by Prof. WU Tonghua at the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences (CAS) conducted a systematic inventory and classification of landslides in the Babao River Basin of the Qilian Mountains from 2009 to 2018, using multi-source high-resolution remote sensing imagery and UAV surveys. 

This work was published in Advances in Climate Change Research on Nov. 29.

The results showed that landslides were categorized into three types: slides, flows, and slumps. The study recorded 105 events from 2016 to 2018, representing 52% of the total, indicating a significant increase in landslide activity. 

The mean elevation of landslide occurrences increased from 3,343 meters to 3,474 meters, a rise of about 130 meters. This upward shift in landslide activity closely matches the rising lower boundary of permafrost, as shown by comparing these findings with model-based permafrost distribution maps. 

Landslide activity was mainly concentrated in discontinuous permafrost zones between 3,200 and 3,800 meters. Intensified freeze-thaw cycles reduced surface mechanical strength and increased pore water pressure, exacerbating landslide risks. 

Further analysis shows that climate change, driven by rising annual temperatures and precipitation, has significantly raised the lower permafrost boundary and reduced slope stability in discontinuous permafrost regions. 

This study offers initial insights into the interactions between landslides and permafrost degradation, providing crucial evidence for predicting and preventing geological hazards in high-altitude regions. As climate warming continues, landslide activity in high-altitude permafrost areas is likely to increase, raising the frequency and intensity of such disasters.

It is urgently necessary to enhance high-resolution landslide monitoring, deepen process-based mechanistic research, optimize early warning systems, and develop more precise disaster prevention strategies.