Attribution discernment of climate change and human interventions to runoff decline in Huangshui River Basin, China

Abstract

To achieve sustainable development goals in Huangshui River Basin (HRB), strengthening adaptive water resources management under the dual impact of climate change (CC) and human interventions (HI) is of great significance. Multiple mathematical and statistical methods were employed to determine the runoff trend and breakpoint in HRB. The elasticity of CC and HI on the runoff decline and their contributions were quantitatively discerned based on the Budyko hypothesis, complementary method, and SWAT hydrological model. The results show that (1) the runoff showed a decreasing trend, with a runoff breakpoint in 1990; (2) the elasticity coefficients indicated a 1% increase in P, ET0, and n, leading to a 2.19% increase, a 1.19% decrease, and a 1.52% decrease in the runoff, respectively; (3) the Budyko framework determined the contribution of CC and HI to runoff decline in HRB to be 37.98–41.86% and 58.14–62.02%, respectively, and that estimated by SWAT hydrological model to be 38.72 and 61.28%, respectively; (4) HI were the primary factor for runoff decline in HRB, where direct anthropogenic disturbances such as water withdrawals and water conservancy project construction were the main drivers. The findings have important scientific significance for water resources planning and management in HRB. HIGHLIGHTS We determined the change trend and breakpoint of annual runoff from 1959 to 2014.; The runoff elasticity was estimated theoretically based on the Budyko hypothesis for 20 mountainous catchments and 5 hydrographic cross-sections in HRB.; The complementary method calculated the contribution threshold of climate change and human interventions to runoff changes.; SWAT models were used to discern runoff change attributions.;

Keywords

• budyko hypothesis
• climate change
• huangshui river basin
• human interventions
• runoff change
• swat model