大通河流域地处青藏高原东北部边缘，生态环境敏感脆弱，开展变化环境下水资源演变、归因研究对保护区域水生态环境，保障水生态文明建设具有十分重要的意义。采用线性倾向估计、集中度、集中期、有序聚类检验、小波分析等统计方法，分析了流域径流的年际变化、年内分配、周期和突变变化特征，基于累积量斜率变化率法和双累积曲线定量评估了气候因素和人类活动对径流变化的影响。结果表明：（1） 近60 a大通河流域气候暖湿化明显，年平均气温、降水量、潜在蒸发量增幅分别为0.42 ℃·(10a)^-1和8.9 mm·(10a)^-1、5.6 mm·(10a)^-1，年径流呈减少趋势，倾向率0.67×10⁸ m³·(10a)^-1。（2） 径流集中度和不均匀系数呈微弱下降趋势，枯季径流增加趋势明显，年内分配更趋于均匀，集中期有推迟趋势，延迟速率为3.0 d·(10a)^-1。（3） 年径流在44 a左右尺度上周期震荡明显，突变发生在1990年，突变后径流量减少3.52×10⁸ m³，流域冰川分布呈减小趋势，植被覆盖无显著变化。（4） 气候、人类活动对大通河径流减少的贡献率分别为-17.7%和117.7%，降水量是流域来水的主要补给来源，跨流域调水是引起径流减小的主要驱动因素。

The Datong River Basin is located on the northeastern edge of the Qinghai-Tibet Plateau and is a sensitive and fragile ecological environment. It is of great significance to conduct research on the evolution and attribution of water resources in changing environments for the protection of the water ecological environment in the area and the construction of water ecocivilization. Statistical methods such as linear regression, concentration degree, concentration period, ordered clustering test, and wavelet analysis were used to analyze the characteristics of annual variation, seasonal distribution, periodicity, and abrupt changes in basin runoff. On the basis of the cumulative slope change rate method and double cumulative curve, the effects of climate factors and human activities on runoff changes were quantitatively evaluated. The results showed the following: (1) The climate in the Datong River Basin had warmed and humidified significantly in the past 60 years, with increases in average annual temperature, precipitation, and potential evapotranspiration of 0.42 ℃·(10a)^-1, 8.9 mm·(10a)^-1, and 5.6 mm·(10a)^-1, respectively. The annual runoff showed a decreasing trend, with a tendency rate of 0.67×10⁸ m³·(10a)^-1. (2) The concentration degree and uneven coefficient of runoff showed a weak downward trend, and the increasing dry season runoff trend was evident. The seasonal distribution was more uniform, and the concentration period showed a delayed trend, with a delay rate of 3.0 d·(10a)^-1. (3) The annual runoff oscillated significantly at a scale of approximately 44 years, and the mutation occurred in 1990. After the mutation, runoff decreased by 3.52×10⁸ m³. The distribution of glaciers in the basin showed a decreasing trend, whereas the vegetation cover did not show a significant change. (4) The contributions of climate and human activities to the runoff decrease in the Datong River were -17.7% and 117.7%, respectively. Precipitation was the main source of water supply in the Datong River Basin, and interbasin water transfer was the main driving factor for runoff reduction.