Abstract: Based on long??term hydrological and meteorological observat ion data, the runoff change was analyzed ondifferent time- scales monthly, annual and inter??decadal, and in representative dry and wet years in Yang River Basinwith numerical analysis method. And also, Regression analysis was used to establish the correlation between runoff andprecipitation at different t ime- scales. More importantly, however, precipitation??runoff mode was adopted to quantify theimpact of human activity and climate change on runoff, and the respective impact of human activity and climate change onrun off isolated. Results showed that runoff was experiencing a great decrease especially after the 1980s, besides the impactof climate change, human activit ies such as industrial and agriculture water use, the increase of domest ic water taken for rapid population growth, soil and water conservation measures as reservoir water storage were the main reasons of runoff decrease. And on average, 83. 2% of total runoff decrease was driven by human activit ies.

Key words: Yang River Basin, Runoff decrease, Precipitation, Climate change, Human activities

CLC Number: 

• S16