Abstract: As climate change and human activities have had a profound and lasting impact on the hydrologic progresses, it is urgent to assess and separate the responses of runoff to the two driving factors. In this study, the variations of precipitation, evaporation and temperature in the Yongding River basin were examined for over five decades in 1957-2010. The results show that it is a wet period during the 1960s and 1970s but a dry period since 1980s. Climate change and human activities have significant influences on the runoff in this basin. The SWAT hydrological model was established to confirm the need of runoff restoration for the following research. With regard to the runoff quantitative responses to climate change and human activities, climate change is the dominant influence factor with a contribution of 65.4%. However, as the value of observed stream flow is almost equal to that caused by human activities, the driving factor of human activities cannot be neglected in future study.

Key words: climate change, human activities, runoff, quantitative assessment