Ground Deformation and Permafrost Degradation in the Source Region of the Yellow River, in the Northeast of the Qinghai-Tibet Plateau

Abstract

The source region of the Yellow River (SRYR) is situated on the permafrost boundary in the northeast of the Qinghai-Tibet Plateau (QTP), which is an area highly sensitive to climate change. As a result of increasing global temperatures, the permafrost in this region has undergone significant degradation. In this study, we utilized Sentinel-1 to obtain ground surface deformation data in the SRYR from June 2017 to January 2022. We then analyzed the differences in terrain deformation under various environmental conditions. Our findings indicated an overall subsidence trend in the SRYR, with a long-term deformation velocity of −4.2 mm/a and seasonal deformation of 8.85 mm. Furthermore, the results showed that terrain deformation varied considerably from region to region, and that the Huanghe’ yan sub-basin with the highest permafrost coverage among all sub-basins significantly higher subsidence rates than other regions. Topography strongly influenced ground surface deformation, with flat slopes exhibiting much higher subsidence rates and seasonal deformation. Moreover, the ground temperature and ground ice richness played a certain role in the deformation pattern. This study also analyzed regional deformation details from eight boreholes and one profile line covering different surface conditions, revealing the potential for refining the permafrost boundary. Overall, the results of this study provide valuable insights into the evolution of permafrost in the SRYR region.

Analysis and partitioning of terrestrial water storage in the Yellow River source region

“…The increasing rates in SWE successively decreased from northwest to southeast, with SM and GWS exhibiting the same pattern. The YRSR is located on the permafrost boundary in the northeastern QTP, which is highly sensitive to climate change (Li et al, 2023). Areas with a decreasing PM trend accounted for 94.7% of the YRSR subareas.…”

“…The mean annual T of −2.5°C and P of 532.5 mm have been calculated using the inverse distance‐weighted average method and elevation correction. Permafrost is widely distributed in the YRSR, and accounts for approximately 43.8% of the total area, while seasonally frozen ground accounts for approximately 56.2% of the total area (Li et al, 2023). However, glacier area constitutes only 0.1% of the YRSR's total area and melting ice flow accounts for just 0.35% of the total runoff in the region (He et al, 2021).…”