Abstract:Based on the ABCD model, this study proposed an analysis framework to quantify the impact of climate change and human activities on runoff change, and carried out an attribution analysis in the Beidasha River basin on different time scales based on this framework and the elasticity method. The results showed that the contribution of climate change to runoff increase is 43 mm and 32 mm by ABCD model and the elastic coefficient method on the mean annual scale from the base period (1980-1990) to the disturbed period (2006-2018), respectively. The impact of human activities on runoff is equal to that of climate change. The elasticity method does not consider the change of annual distribution of meteorological elements, which may underestimate the impact of climate change. On the monthly scale, climate change increases the runoff by 4-19mm and 1-3mm during flood season and other months, respectively, which is dominant in summer and autumn. Human activities increase runoff by 11 mm in September and decrease runoff by 1-11 mm in other months, which are dominant in spring and winter.