The study looked at changes in river runoff in the Yellow River in China from 1965 to 2016. They found that human activities and climate change have both affected the river's flow. In the upper reaches, both factors had a similar impact on runoff, while in the middle reaches, human activities played a bigger role. The construction of reservoirs and water consumption in the upper reaches, and water conservation efforts in the middle reaches, were key factors in the changes. The researchers used statistical tests and data analysis to identify trends and breakpoints in runoff changes, showing that climate change and human activities have influenced the river's flow over time.