Effects of climate change and land use on runoff in the Huangfuchuan Basin, China

It is necessary to comprehend the impacts of climate change and human activities on hydrological processes to effectively manage water resources. This study focuses on the Huangfuchuan Basin and investigates changes in hydrology and land use within the basin. The Budyko method and the water and energy processes (WEP) hydrological model were employed to assess the effects of climate change and underlying surface changes on runoff. The results showed that: (1) Runoff in the Huangfuchuan Basin exhibited a pronounced decreasing trend between 1960 and 2015, with an annual average runoff of 42.82 m(3)/s. (2) According to the Budyko method, the underlying surface change had the highest contribution rate to runoff at 83.54 %, followed by rainfall at 12.28 %. (3) Based on the simulation of the WEP hydrological model, climate change contributed to 22.08 % of the runoff change. Land use change accounted for 65.95 % of the runoff change. (4) Various future climate change scenarios were examined in this study. The maximum average runoff simulated by the model occurred when rainfall increased by 20 % and temperature decreased by 20 %, resulting in a 13.485 m(3)/s increase compared to the base scenario. (5) The simulated annual runoff, from highest to lowest, was as follows: urban development scenario (19.71 m(3)/s) > ecological protection scenario (18.68 m(3)/s) > baseline scenario (13.17 m(3)/s). This study enhances our understanding of runoff variation in the Huangfuchuan Basin and provides a valuable foundation for water resource management and conservation on the Loess Plateau, China.