为相对全面客观地分析气候变化和人类活动对河南省主要河川径流变化的影响，基于河南省内卫河、伊洛河、洪汝河和唐河流域1961—2022年径流和降水资料，以及国家气候中心根据Penman-Monteith公式计算的年潜在蒸散发资料，比较4个蒸发对比站年潜在蒸散发和蒸发皿年蒸发值，运用Mann-Kendall突变检验法和累积双曲线法分析4个研究流域控制水文站年径流序列的变化趋势和突变年份，以及4个流域年降水和潜在蒸散发的变化趋势。采用基于Budyko假设的弹性系数法对径流变化开展归因分析。结果表明：4个蒸发对比站年潜在蒸散发与蒸发皿年蒸发变化趋势基本一致，4个水文站年径流深及4个流域年降水和年潜在蒸散发均呈下降趋势。4个水文站年径流深分别在1977年、1985年、2008年和2010年发生了突变。气候变化对径流减少的贡献率在卫河和伊洛河流域为7%以下，在洪汝河和唐河流域约为12%～18%，降水减少不显著和潜在蒸散发呈下降趋势是贡献率小的原因，可见人类活动是影响4个流域径流变化的主要驱动因素。

With the rapid development of the social economy in Henan Province, runoff reduction is more serious. Attribution analysis of runoff variation can provide a scientific basis for water resources management. Henan Province spans the Yangtze River, the Yellow River, the Huaihe River, and the Haihe River, the water system is complex. The climate is diverse, and the economic development is unbalanced among different places, so the impact of climate change and human activities on runoff variation is different. In the past, some studies on the attribution analysis of runoff variation were carried out in Henan Province, but the conclusions are not consistent. To get a relatively comprehensive and objective attribution rate, it is necessary to carry out the attribution analysis of runoff variation in representative basins in Henan Province based on accurate meteorological and hydrological data.The Weihe River basin, Yiluohe River basin, Hongruhe River basin, and Tanghe River basin in Henan Province were selected as study basins, which are sub-basins of the Haihe River basin, the Yellow River basin, the Huaihe River basin, and the Yangtze River basin, respectively, and their control hydrologic stations are Yuancun station, Heishiguan station, Bantai station, and Guotan station. Based on annual runoff and precipitation data of the four study basins from 1961 to 2022, and annual potential evapotranspiration by the Penman-Monteith method from National Climate Center, the Mann-Kendall mutation test and double cumulative curves method were used to analyze the mutation years of annual runoff depth series of control hydrologic stations, and the change trends of annual runoff depth of control stations, annual precipitation and annual potential evapotranspiration of the study basins were also analyzed. Annual potential evapotranspiration was compared with observed annual evaporation. The elastic coefficient method based on the Budyko hypothesis was applied to assess the attribution rate of climate change and human activities to runoff variation.The results showed that: (1) The annual runoff depth of the four hydrologic stations showed a decreasing trend. The annual precipitation of the four study basins showed an insignificant decreasing trend. The potential evapotranspiration also indicated a decreasing trend and the decreasing trend was significant in the Weihe River basin, Hongruhe River basin, and Tanghe River basin, but not significant in the Yiluohe River basin. The changing trend of annual potential evapotranspiration and observed annual evaporation at the four weather stations was consistent. (2) The mutation of annual runoff of Yuancun station, Heishiguan station, Bantai sation, and Guotan station occurred in 1977, 1985, 2008, and 2010, respectively. (3) The contribution rates of climate change to runoff reduction were less than 7% in the Weihe River and Yiluohe River basins, and about 12%?18% in the Hongruhe River and Tanghe River basins. The contribution rates of human activities were about 93%?97% in the Weihe River and Yiluohe River basins, and about 82%?88% in the Weihe River and Tanghe River basins. The climate change showed low contribution rates because of the insignificant decrease in precipitation and the decrease in potential evapotranspiration . Therefore, it can be seen that human activities were the main influencing factor of runoff reduction in the four study river basins.