Assessing the impacts of climate change and human activities on runoff is important for planning and managing water resources and for maintaining the integrity of the ecosystem, as well as the normal operation of modern society. In this study, the distribution of precipitation in the Beichuan River basin from 1961 to 2013 is uneven, and we analyzed the impacts of climate change and human activity on the annual and seasonal runoff change during this period. The results showed that runoff was more sensitive to precipitation than the other meteorological factors during the study period, and a 10% increase in precipitation could increase runoff by 17.5%. The annual runoff showed a downward trend during the past 53 years, with an abrupt change point in 1972. We concluded that human activities were mainly responsible for the runoff reduction, and climate change accounted for approximately 30% of the reduction. For the change in seasonal runoff, the dry season runoff had no significant trend, but there was a downward trend in the wet season runoff, with an abrupt change point in 1998. We concluded that human activities were the dominant cause of the reduction in the wet season runoff (88.27%), and climate change accounted for 11.73% of the reduction.

评估气候变化和人类活动对径流的影响对于规划和管理水资源，维护生态系统的完整性以及现代社会的正常运转至关重要。在本研究中，北川河流域1961年至2013年的降水分布是不均匀的，我们分析了气候变化和人类活动对这一时期的年，季径流量变化的影响。结果表明，在研究期间，径流对降水比其他气象因素更为敏感，降水增加10％可使径流增加17.5％。在过去的53年中，年度径流量呈下降趋势，并在1972年出现突变点。我们得出结论，人类活动是造成径流量减少的主要原因，气候变化约占减少量的30％。对于季节性径流量的变化，旱季径流量没有显着趋势，但湿季径流量有下降趋势，1998年出现突变点。我们得出结论，人类活动是减少径流量的主要原因。雨季径流（88.27％），而气候变化占减少量的11.73％。