Evolution laws and attribution analysis in the Yarlung Zangbo River basin
摘要
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.