Dataset of Variation and Driving Mechanisms of Active Layer Thickness in the Permafrost Region of the Daxing’anling Mountains, Northeast China

Temporally, the ALT in the study area increased significantly at a rate of (0.44±0.20) cm·a-1, indicating a continuous degradation trend of permafrost in this region over the past 40 years. Meanwhile, the thickening rate of ALT increased from (0.30±0.05) cm·a-1 in the northern extensive continuous permafrost zone to (0.53±0.21) cm·a-1 in the southern island, sporadic, and scattered permafrost zone.

SEM analysis revealed that mean annual air temperature exerted a significant driving effect on ALT changes (total effect = 0.79); soil moisture showed a significant inhibitory effect (total effect = −0.41); and factors such as air temperature, precipitation, and vegetation cover jointly influenced ALT dynamics through complex interactions. In conclusion, from 1982 to 2022, the ALT in the Daxing’anling Mountains permafrost region thickened significantly, with a clear permafrost degradation trend that intensified from north to south, and its change was primarily regulated by the combined effects of air temperature and soil moisture.

This study would provide a scientific basis for monitoring mid-to-high latitude permafrost degradation and assessing its ecological and environmental effects.