资源环境科技发展态势分析平台

Climate warming causes significant changes in regions with seasonally frozen ground and permafrost, and these changes have a profound impact on the balance of water resources, ecological security and engineering structures in cold regions. Based on daily soil freezing depth and temperature data from 31 meteorological stations in Heilongjiang Province, combined with 11 global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6), the detailed spatiotemporal evolution of the maximum freezing depth of seasonally frozen ground (SFD) and permafrost continuity in Heilongjiang Province during 1960–2014 and 2015–2100 were analyzed. The results show that (1) average maximum SFD in the early 21st century is approximately 30.78 cm lower than that in the 1960s, and the maximum reduction occurs in the high elevation central part of the study area; under the four scenarios, SSP126, SSP245, SSP370 and SSP585, the SFD will decrease by 7.68, 19.44, 38.34 and 43.06 cm, respectively, by 2100. (2) Permafrost regions with continuities of 70%–80% (P₇₀), 30%–70% (P₃₀) and 5%–30% (P₅) and seasonally frozen ground areas in the 1960s accounted for 8.43%, 7.44%, 21.89% and 62.24% of the total study area, respectively. In the early 21st century, they accounted for 3.08%, 11.39%, 17.50% and 68.04%, respectively. The permafrost region will decrease by 47.36% and 61.34% by 2100 under SSP126 and SSP245, respectively, and will disappear under SSP370 and SSP585. (3) The abrupt change in seasonally frozen ground is basically consistent with the change in temperature, but the abrupt change in permafrost exhibits a lag relative to the change in temperature. The maximum SFD and permafrost region in the study area will decrease by 21.62 cm and 45.98%, respectively, in response to a temperature increase of 1 °C.