季芳, 范林峰, 匡星星, 邹一光, 郑春苗. 青藏高原多年冻土退化对蒸散发的影响[J]. 水科学进展, 2022, 33(3): 390-400. DOI: 10.14042/j.cnki.32.1309.2022.03.004
引用本文: 季芳, 范林峰, 匡星星, 邹一光, 郑春苗. 青藏高原多年冻土退化对蒸散发的影响[J]. 水科学进展, 2022, 33(3): 390-400. DOI: 10.14042/j.cnki.32.1309.2022.03.004
JI Fang, FAN Linfeng, KUANG Xingxing, ZOU Yiguang, ZHENG Chunmiao. Role of permafrost degradation on evapotranspiration on the Qinghai-Tibet Plateau[J]. Advances in Water Science, 2022, 33(3): 390-400. DOI: 10.14042/j.cnki.32.1309.2022.03.004
Citation: JI Fang, FAN Linfeng, KUANG Xingxing, ZOU Yiguang, ZHENG Chunmiao. Role of permafrost degradation on evapotranspiration on the Qinghai-Tibet Plateau[J]. Advances in Water Science, 2022, 33(3): 390-400. DOI: 10.14042/j.cnki.32.1309.2022.03.004

青藏高原多年冻土退化对蒸散发的影响

Role of permafrost degradation on evapotranspiration on the Qinghai-Tibet Plateau

  • 摘要: 青藏高原作为“亚洲水塔”对气候变化极为敏感,研究气候变化下青藏高原多年冻土退化对蒸散发的影响有助于理解多年冻土地区水文过程对气候变化的响应情况。基于Budyko-Fu假设,构建了考虑多年冻土活动层厚度变化的水热耦合模型,建立了符合青藏高原多年冻土区的模型参数化方案,通过设置情景假设探讨了多年冻土退化对蒸散发的影响。模拟结果表明:1982—2018年青藏高原多年冻土区平均年蒸散发为275.6 mm,空间分布由东南向西北递减;研究区年蒸散发整体上以3.57 mm/a的速率上升。多年冻土活动层加深会引起蒸散发的增大,忽略冻土退化因素将导致约2.2%的蒸散发低估。冻土退化对蒸散发的影响呈现显著的空间异质性,土壤有效含水量和植被覆盖度越低的地区,蒸散发对冻土退化的响应越敏感。

     

    Abstract: The Qinghai-Tibet Plateau (QTP), known as the "Asian Water Tower", is extremely sensitive to climate change. Studying the impacts of permafrost degradation on evapotranspiration is conducive to improving the understanding of the response of hydrological processes and water balance to climate change in the QTP. Based on the Budyko-Fu hypothesis, a coupled hydrothermal model was constructed to account for the active layer deepening of the permafrost regions with a model parameterization scheme suitable for the QTP. The results show that the annual average evapotranspiration in the permafrost regions on the QTP is 275.6 mm during 1982—2018 and shows a descending gradient from southeast to northwest. The overall evapotranspiration in the permafrost areas on the QTP increased significantly at a rate of 3.57 mm/a (p < 0.05). Deepening of the active layer causes increased evapotranspiration while ignoring the permafrost degradation would result in an underestimation of evapotranspiration by about 2.2%. The effects of permafrost degradation on evapotranspiration exhibit a significant spatial heterogeneity. The lower the soil available water capacity and vegetation coverage are, the more sensitive the responses of evapotranspiration to permafrost degradation become.

     

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