Spatiotemporal change and attribution analysis of future runoff on the Yellow River basin of China

Study region: The Yellow River basin (YRB) Study focus: Runoff plays an important role in ecology and hydrology, which can be affected by climate change and human activities. The fractional vegetation cover can reflect the influence of human activities on underlying surface to some extent. However, the attribution research on future runoff changes is not sufficient. Using the CMIP6 global climate model with Deltadownscaling, Budyko equation, and empirical orthogonal function method, the effects of climate change and underlying surface change on runoff in the YRB from 2022 to 2100 are analyzed in this paper. New hydrological insights for the region: The trend of runoff increased uniformly on the YRB except for the upstream of the YRB and some areas of the source region of the YRB. Runoff is negatively correlated with potential evapotranspiration and underlying surface change but positively correlated with precipitation, according to the Budyko equation. And the increase in the concentration of emissions will amplify the impact of climate change particularly precipitation on runoff. In most areas of the basin, precipitation changes will be the dominant factor in runoff changes between 2022 and 2100, and their contribution rate will increase over time. On the source region of the YRB, however, the potential evapotranspiration dominated runoff changes. This study will help formulate appropriate soil and water conservation and ecological protection strategies in ecologically vulnerable areas of the YRB in the context of climate change.