雅鲁藏布江流域径流演变规律与归因分析

气候变化驱动下的水循环与水资源演变规律研究是重要的科学问题, 也是国际社会普遍关注的全球性问题。以雅鲁藏布江流域为研究区, 利用线性倾向估计、多元线性回归等方法检验气象要素变化特征, 揭示下垫面演变规律；基于Budyko假设的弹性系数法, 揭示径流演变规律, 并进行归因分析。结果表明: 1961—2014年, 雅鲁藏布江流域气温呈升高趋势, 降水整体呈增加趋势, 气候向暖湿化方向发展；植被整体改善, 上游西北部和下游植被存在退化现象；年径流序列具有3~4 a、12 a、20 a和32 a左右的周期；降水变化、潜在蒸散发量变化、下垫面变化和冰川变化对径流量增加的贡献率分别为39.62%、-2.74%、32.32%和30.94%。相关结果对理解气候变化和下垫面变化下雅鲁藏布江径流演变规律, 具有重要的参考价值。

Evolution laws and attribution analysis in the Yarlung Zangbo River basin

Study on the evolution law of hydrological cycle and water resources driven by climate change is not only an important scientific issue, but also a global issue of concern to the international community. The Yarlung Zangbo River basin was selected as the study area. Linear trend estimation and multiple linear regression methods were applied to test the change characteristics of meteorological factors, and to reveal the evolution law of underlying surface. The elastic coefficient method based on Budyko framework was applied to analyze the runoff changes and make attribution analysis. Results showed that from 1961 to 2014, the temperature in the entire Yarlung Zangbo River basin showed an upward trend, and the precipitation showed an increasing trend, indicating that the Yarlung Zangbo River basin was experiencing climate warming and wetting. The vegetation showed a greening trend, while there was a certain degradation in the northwest and downstream. The annual runoff series showed the cyclic periods of 3—4 years, 12 years, 20 years and 32 years. The contribution of precipitation, potential evapotranspiration, underlying surface and glacier changes to the increase of runoff accounted on 39.62%, -2.74%, 32.32% and 30.94%, respectively. The results have significant reference for understanding the runoff evolution law of the Yarlung Zangbo River basin under the condition of climate changing and underlying surface changing.