Abstract: The Qinghai-Tibet Plateau is a region impacted most dramatically by climate change. The trends of changes in the river runoff and their causes have attracted much attention. In this study, the Mann-Kendall trend test and the Pettitt test are used to detect the runoff variations from 1980 to 2016 at 11 hydrological stations in the Tibetan Autonomous Region, and the climate elasticity method based on the Choudhury-Yang equation is used to quantify the effects of precipitation, potential evaporation, and underlying surface changes on annual runoff changes. The results show that the annual runoff in the study area presents an insignificant upward trend, and has an abrupt point around 1997. The sensitivity of the runoff to climate change and underlying surface change is the lowest in the lower reaches of Yarlung Zangbo River. Precipitation is the main factor responsible for annual runoff change and its increase leads to a runoff increase in all basins, but this impact exhibits an obvious regional difference with a spike in the Lhasa River basin.

Key words: Budyko framework, attribution analysis, climate elasticity method, Tibetan Plateau, runoff change, TPHiPr precipitation dataset