Pedosphere (6): 1039--1053, 2025
ISSN 1002-0160/CN 32-1315/P
©2025 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Numerical analysis of thermo-water-vapor-carbon coupling in a permafrost region: A case study in the Beiluhe region of the Qingzang Plateau, China |
Haotian WEI1,2, Enlong LIU1,3 , Chuan HE3, Bingtang SONG1, Dan WANG1, Jian KANG1,2, Ling CHEN1,2, Qiong LI1,2 |
1 Northwest Institute of Eco-Environment and Resources, State Key Laboratory of Frozen Soil Engineering, Chinese Academy of Sciences, Lanzhou 730000 (China);
2 University of Chinese Academy of Sciences, Beijing 100049 (China);
3 State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resources and Hydropower, Sichuan University, Chengdu 610065 (China) |
| ABSTRACT |
| With global warming and the intensification of human activities, frozen soils continue to melt, leading to the formation of thermokarst collapses and thermokarst lakes. The thawing of permafrost results in the microbial decomposition of large amounts of frozen organic carbon (C), releasing greenhouse gases such as carbon dioxide (CO2) and methane (CH4). However, little research has been done on the thermo-water-vapor-carbon coupling process in permafrost, and the interactions among hydrothermal transport, organic matter decomposition, and CO2 transport processes in permafrost remain unclear. We considered the decomposition and release of organic C and established a coupled thermo-water-vapor-carbon model for permafrost based on the study area located in the Beiluhe region of the Qingzang Plateau, China. The model established accurately reflected changes in permafrost temperature, moisture, and C fluxes. Dramatic changes in temperature and precipitation in the warm season led to significant soil water and heat transport, CO2 transport, and organic matter decomposition. During the cold season, however, the soil froze, which weakened organic matter decomposition and CO2 transport. The sensitivity of soil layers to changes in the external environment varied with depth. Fluctuations in energy, water, and CO2 fluxes were greater in shallow soil layers than in deeper ones. The latent heat of water-vapor and water-ice phase changes played a crucial role in regulating the temperature of frozen soil. The low content of soil organic matter in the study area resulted in a smaller influence of the decomposition heat of soil organic matter on soil temperature, compared to the high organic matter content in other soil types (such as peatlands). |
| Key Words: CO2 transport|ecosystem model|frozen soil|hydrothermal process|release of organic C|water-ice phase|water-vapor phase |
| Citation: Wei H T, Liu E L, He C, Song B T, Wang D, Kang J, Chen L, Li Q. 2025. Numerical analysis of thermo-water-vapor-carbon coupling in a permafrost region: A case study in the Beiluhe region of the Qingzang Plateau, China. Pedosphere. 35(6): 1039-1053. |
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