Study region The eastern Qilian Mountains, located on the northeastern margin of the Tibetan Plateau, span elevations from similar to 2600 to 5300 m around the Menyuan area. It is characterized by cold, alpine climatic conditions and hosts both permafrost and seasonally frozen ground, which are highly sensitive to climate change and have important hydrological and ecological implications. Study focus This study develops an enhanced multi-temporal InSAR framework to monitor frozen ground dynamics in the eastern Qilian Mountains using Sentinel-1 data from 2014 to 2024, with a particular focus on the permafrost-seasonally frozen ground transition zone around Menyuan. It addresses key challenges in permafrost monitoring by implementing a co-seismic deformation separation model, a Common Scene Stack (CSS)-based atmospheric correction method, and a time-series decomposition model with linearly varying annual amplitude to capture evolving freeze-thaw behavior under climate change. New hydrological insights for the region The results reveal clear hydrological and thermal contrasts between permafrost and seasonally frozen ground. Seasonally frozen ground exhibits higher seasonal deformation amplitudes, more rapid interannual changes, and shorter thermal response lags compared to permafrost, reflecting its more dynamic hydrothermal regime. The estimated freeze-thaw layer thickness ranges from 0 to 5.3 m, with thinning trends in seasonally frozen ground at lower elevations and slight thickening of active layers in high-elevation permafrost. These findings highlight ongoing frozen ground degradation and provide new insights into subsurface water-energy interactions and long-term cryospheric responses to climate warming in alpine environments.

来源平台：JOURNAL OF HYDROLOGY-REGIONAL STUDIES