Wang Yunfei, Ye Aizhong, Zhang Yuhang, Yang Fan
State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2023 Nov 1;897:165326. doi: 10.1016/j.scitotenv.2023.165326. Epub 2023 Jul 5.
Runoff from the Qinghai-Tibetan Plateau, a major global water tower, is crucial to regional hydrological processes and the availability of water for a large population living downstream. Climate change, especially changes in precipitation and temperature, directly impacts hydrological processes and exacerbates shifts in the cryosphere, such as glacier and snow melt, leading to changes in runoff. Although there is a consensus on increased runoff due to climate change, it is still unclear to what extent precipitation and temperature contribute to runoff variations. This lack of understanding is one of the primary sources of uncertainty when assessing the hydrological impacts of climate change. In this study, a large-scale, high-resolution, and well-calibrated distributed hydrological model was employed to quantify the long-term runoff of the Qinghai-Tibetan Plateau, and the changes in runoff and runoff coefficient were analyzed. Furthermore, the impacts of precipitation and temperature on runoff variation were quantitatively estimated. The results found that runoff and runoff coefficient decreased from southeast to northwest, with mean values of 184.77 mm and 0.37, respectively. Notably, the runoff coefficient exhibited a significant increasing trend of 1.27 %/10 yr (P < 0.001), while the southeastern and northern regions of the plateau showed a declining tendency. We further showed that the warming and humidification of the Qinghai-Tibetan Plateau led to an increase in the runoff by 9.13 mm/10 yr (P < 0.001). And precipitation is a more important contributor than temperature across the plateau, contributing 72.08 % and 27.92 % to the runoff increase, respectively. At the basin scale, the influence of precipitation and temperature on runoff varies among basins, with the Daduhe basin and the Inner basin being the most and least influenced by precipitation, respectively. This research analyses historical runoff changes on the Qinghai-Tibetan Plateau and provides insights into the contributions of climate change to runoff.
作为全球主要的水塔，青藏高原的径流对区域水文过程以及下游大量人口的用水供应至关重要。气候变化，尤其是降水和温度的变化，直接影响水文过程，并加剧冰冻圈的变化，如冰川和积雪融化，从而导致径流变化。尽管对于气候变化导致径流增加已达成共识，但降水和温度对径流变化的贡献程度仍不明确。这种认识不足是评估气候变化对水文影响时不确定性的主要来源之一。在本研究中，采用了一个大规模、高分辨率且经过良好校准的分布式水文模型来量化青藏高原的长期径流，并分析径流和径流系数的变化。此外，还定量估计了降水和温度对径流变化的影响。结果发现，径流和径流系数从东南向西北递减，平均值分别为184.77毫米和0.37。值得注意的是，径流系数呈现出显著的增加趋势，为1.27%/10年（P < 0.001），而高原的东南部和北部地区则呈下降趋势。我们进一步表明，青藏高原的变暖和湿润导致径流增加了9.13毫米/10年（P < 0.001）。在整个高原地区，降水对径流增加的贡献比温度更为重要，分别为72.08%和27.92%。在流域尺度上，降水和温度对径流的影响因流域而异，大渡河流域和内陆流域分别受降水影响最大和最小。本研究分析了青藏高原历史径流变化，并深入了解了气候变化对径流的贡献。
