中文摘要：

气候变化和人类活动影响下径流变化的归因研究对于应对径流变化具有重要价值。以渭河的北洛河流域为研究对象，应用Budyko假设和TOPMODEL模型分析了气候变化和人类活动对径流的贡献率，在较可能的气候变化范围内设定气温和降水变化的25种情景，分析了各情景对径流的影响。结果表明，历史降水、径流呈减少趋势，气温呈增加趋势，气温的升高和降水量的减少同时影响径流量的变化。两种模型模拟的人类活动对径流的贡献率分别为58．9％和65．2％，人类活动是近50年来径流量显著下降的主要原因。不同气候变化情景下的月径流变化有明显差异，降水变化对径流的影响大于气温，表明流域未来降水变化是影响水资源变化的主要因素。

英文摘要：

Studies on the attribution of runoff variation under climate change and human activities are valuable to understanding runoff change. This paper analyzes the quantitative contribution of climate change and human activities to runoff variation, using the Budyko assumption and TOPMODEL with application to a case study of the Beiluo River basin of the Wei River. We have examined 25 scenarios of temperature and precipitation changes in the possible range of clirnate changes, and analyzed the influence of all these scenarios on the runoff. Simulation results show that historic precipitation and runoff took a decreasing tendency while temperature had a rising trend and both temperature rising and precipitation decreasing made contribution to runoff change. But human activities were the major cause for runoff decreasing over the last 50 years and this had a contribution rate up to 58.9% and 65.2% by the two methods respectively. Under different scenarios, the variation in monthly runoff shows a wide range and the influence of precipitation change is stronger than that of temperature change, indicating precipitation change as a major factor of the future variation in water resources.