Hydrological impacts of near‐surface soil warming on the Tibetan Plateau

• Published in: Permafrost and Periglacial Processes
• Main Authors: Liu, Li, Zhang, Wenjiang, Lu, Qifeng, Jiang, Huiru, Tang, Yi, Xiao, Hongmin, Wang, Genxu
• Other Authors: Innovative Research Group Project of the National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Arctic; permafrost; Permafrost and Periglacial Processes
• Online Access: http://dx.doi.org/10.1002/ppp.2049; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fppp.2049; https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2049; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2049

Abstract Climate warming can cause intense changes in regional soil freeze/thaw dynamics and thus exerts strong effects on hydrological processes. Because permafrost conditions vary widely across the Tibetan Plateau (TP), a better understanding the potential influences of permafrost types is helpful to project future hydrological changes. Using multilayer soil temperatures from 45 meteorological stations, this study investigated regional near‐surface soil warming on the TP (1981–2015) and related hydrological implications in two typical alpine basins. In cold and warm seasons, near‐surface soil temperature gradient (0–5 cm) showed significant increasing trends with average rates of 0.31 ± 0.13 and 0.19 ± 0.08°C per decade ( p < 0.05), respectively. This implied increasingly more heat transferred downward from the ground surface annually, which also appeared in the deeper layer (5–10 cm) but was relatively weaker. Our results also reflected that increasing warming tended to cause higher baseflow (0.66 m 3 s −1 a −1 , p < 0.10) and quicker groundwater recession (−0.05 per decade, p < 0.05) in the permafrost‐dominated (>60%) basin, but had much weaker hydrological effects in the low‐permafrost (<20%) basin. The contrasting responses suggested similar hydrological impacts related to the fraction of permafrost coverage as in the circum‐Arctic regions. Our study implies that the warming‐induced weakening of freezing process has complicated hydrological impacts in the Tibetan basins dependent on the fraction of permafrost coverage.