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DOI	10.1016/j.coldregions.2023.103945
	Effects of seasonal rainfall variations on the hydrothermal state and thermal stability of the permafrost active layer in the central Qinghai-Tibet Plateau of China
	Zhou, Zhixiong; Zhou, Fengxi; Zhang, Mingli; Lei, Bingbing; Ma, Anjing
发表日期	2023
ISSN	0165-232X
EISSN	1872-7441
卷号	214
英文摘要	Rainfall significantly impacts the hydrothermal state and thermal stability of the permafrost active layer by modifying surface energy boundary conditions. The quantitative characterization of hydrothermal changes in the Qinghai-Tibet Plateau has long been a crucial issue, yet the mechanisms underlying the effects of seasonal rainfall on the hydrothermal state within the permafrost active layer remain poorly understood. Therefore, this study investigated the influence of seasonal rainfall variations on the hydrothermal state within the permafrost active layer based on a water-vapour-heat coupled model that optimises the surface energy balance boundary conditions. The results show that regardless of whether the spring rainfall changes or not, the Bowen ratio is >1, indicating that the main energy exchange mode between the atmosphere and surface is sensible heat flux. But following the increase in rainfall in summer and autumn, the Bowen ratio is <1, indicating that the main energy exchange mode is latent heat flux. Meanwhile, increased seasonal rainfall leads to an increase in liquid water flux and a decrease in water vapour flux, whereas decreased seasonal rainfall leads to the opposite trend. Heat conduction, water vapour thermal convection, and water vapour diffusion latent heat decrease with increasing rainfall in various seasons. However, liquid water thermal convection increases with increasing rainfall during various seasons. Seasonal rainfall variations ultimately affect permafrost thermal stability by influencing watervapour migration and energy changes within the permafrost active layer. Among them, the active layer thickness remains basically unchanged after the spring rainfall increases by 2.0 times, whereas it decreases by 4 and 6 cm after the summer and autumn rainfall increase by 1.5 and 2.0 times, respectively. Additionally, when the rainfall during spring, summer, and autumn decreases by 2.0, 1.5, and 2.0 times, respectively, the active layer thickness increases by 7, 6, and 3 cm, respectively. Therefore, increased seasonal rainfall can alleviate permafrost degradation. Otherwise, it is unfavourable for the preservation of permafrost thermal stability.
关键词	Permafrost Active layer Seasonal rainfall variation Hydrothermal change Thermal stability Qinghai -Tibet Plateau
英文关键词	INCREASED PRECIPITATION; NUMERICAL-ANALYSIS; HEAT-TRANSPORT; SURFACE ALBEDO; SENSIBLE HEAT; SOIL; VARIABILITY; SIMULATIONS; EMBANKMENT; DYNAMICS
WOS研究方向	Engineering, Environmental ; Engineering, Civil ; Geosciences, Multidisciplinary
WOS记录号	WOS:001037853600001
来源期刊	COLD REGIONS SCIENCE AND TECHNOLOGY
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283008
作者单位	Lanzhou University of Technology; Lanzhou University of Technology; Nanjing University
推荐引用方式 GB/T 7714	Zhou, Zhixiong,Zhou, Fengxi,Zhang, Mingli,et al. Effects of seasonal rainfall variations on the hydrothermal state and thermal stability of the permafrost active layer in the central Qinghai-Tibet Plateau of China[J],2023,214.
APA	Zhou, Zhixiong,Zhou, Fengxi,Zhang, Mingli,Lei, Bingbing,&Ma, Anjing.(2023).Effects of seasonal rainfall variations on the hydrothermal state and thermal stability of the permafrost active layer in the central Qinghai-Tibet Plateau of China.COLD REGIONS SCIENCE AND TECHNOLOGY,214.
MLA	Zhou, Zhixiong,et al."Effects of seasonal rainfall variations on the hydrothermal state and thermal stability of the permafrost active layer in the central Qinghai-Tibet Plateau of China".COLD REGIONS SCIENCE AND TECHNOLOGY 214(2023).