The study looked at how changes in the environment and human activities impact river runoff in the Loess Plateau of China. Researchers analyzed 57 years of data from 27 rivers and found that the consistency of annual runoff data at 21 hydrological stations was affected by changes in runoff generation and confluence. They identified three periods with different runoff patterns: some stations had decreased runoff after 2000, others showed a shift in runoff patterns around 1970, and some experienced a transition from high to low flow periods before and after 1970.