Quantifying spatiotemporal dynamics of soil frost heave over the Qinghai-Tibet Plateau with process-based hydrothermal modeling

The frost heave phenomenon in frozen soil serves as a direct factor that can induce surface ground deformation and heighten the risk of geological hazards. Quantitative research on frozen soil dynamics and its frost heave at the regional scale is pivotal for conducting risk assessments and prevention of freeze–thaw disasters on a large-scale. However, current regional-scale quantitative research on frozen soil frost heave is rather limited. In this study, a large-scale and long-term dataset of frozen soil characteristic parameters spanning the Qinghai-Tibet Plateau (QTP) from 2010 to 2020 was obtained by employing the methodology of distributed numerical simulation. The seasonal variations of the soil freezing-thawing cycle were analyzed, and a spatial parameterization method of soil frost heave was proposed. The temporal and spatial evolution of the frozen soil frost heave characteristics in the QTP was quantitatively analyzed. We found that over 95 % of the regions in the QTP experience frost heave of less than 0.1 m. The regions with the severest frost heave have displayed a continuous upward trend, suggesting an increased risk of freeze–thaw disasters in these areas. The frost heave rate across the QTP exhibits characteristics of weakening in the east, strengthening in the west, and relative stability in the hinterland. In the southeastern margin of the QTP, where human settlements are widely distributed, the amount and rate of frost heave are comparatively low, exhibiting a weakening trend. However, approximately 8.5 % of human settlements in the QTP region are still situated in high-risk areas for frost heave disasters.