Permafrost mapping of the Tarim Basin based on TTOP model for 2005–2020

Permafrost strongly influences hydrological processes, ecosystem stability, and land-atmosphere energy exchange in cold and arid mountain environments. However, in the Tarim Basin (TB), a key permafrost transition zone on the northern margin of the Qinghai-Tibet Plateau, no high-resolution permafrost distribution map is currently available due to sparse ground observations and highly heterogeneous terrain. In this study, we developed an integrated mapping framework that combines kriging-interpolated land surface temperature, ridge-regression-based ground surface temperature estimation, and the temperature-at-the-top-of-permafrost (TTOP) model to simulate 1-km permafrost distribution map for the TB during 2005–2020. The results indicate that permafrost covers approximately 21.75 × 10⁴ km² (21% of the basin), primarily across the high-altitude areas of the Karakoram, Kunlun, Altun, and eastern Tianshan Mountains, while seasonally frozen ground occupies 79.53 × 10⁴ km² (77%). Validation against survey-based maps in the West Kunlun and Aerjin subregions demonstrates higher accuracies (Kappa = 0.84 and 0.52, respectively) than those of two existing large-scale permafrost datasets, with additional filed surveys further supporting the simulated results. The resulting high-resolution permafrost map provides an improved, region-specific basis for evaluating permafrost degradation and its environmental impacts across the TB.