Quantitative attribution of influence of human activities on runoff change in the middle reaches of the Yellow River: A case study of Kuye River Basin

The Yellow River Basin is an important birthplace of the Chinese nation and Chinese civilization, constitutes an important ecological security barrier in China, and is also an important region for population activities and economic development, and has a pivotal strategic position in the overall situation of national development and socialist modernization. Climate change and human activities have combined effects on runoff, and it is difficult to distinguish their respective contributions to runoff change. Based on 62 years of climate and runoff data from Wenjiachuan hydrology Station in the Kuye River Basin in the middle reaches of the Yellow River from 1960 to 2021, a method based on paired years groups of similar precipitation and potential evapotranspiration was established to quantitatively assess the influence of human activities on runoff. The similar climate premises of the paired year groups were characterized by similar quantities (interannual difference less than 2.0％) and similar processes (significance level of annual change less than 0.05). The results showed that, during the study period, the runoff in 2 groups showed a downward trend and the other 2 groups showed an upward trend. Using land use/land cover analysis, the effects of human activities on runoff change in the Kuye River Basin can be well explained quantitatively. This method can be combined with the traditional hydrological methods to provide a better theoretical basis for water resources management in the basin.