A framework for attributing runoff changes based on a monthly water balance model: An assessment across China

•A simple framework is proposed to quantify the impacts of climate change and human activities on runoff change on mean annual and seasonal scales.•Annual runoff shows a significant decreasing trend in northern China and a nonsignificant increasing trend in southern China.•Climate change has more than 50% contribution in southern China except some catchments in winter.•Human activities dominate seasonal runoff change in the upper-middle reaches of Yellow River except in spring and in the middle reaches of Yangtze River in winter.