Potential effects of climate change on runoff in the Yellow River basin of China

Water scarcity is one of the most challenging issues in arid and semi-arid regions. In the Yellow River basin, rapid growth of population, urbanization, and industrialization have caused ever-increasing competition for water. This study was conducted to evaluate the potential effects of climate change on mean annual runoff in the Yellow River basin under different climate change scenarios projected by the Hadley Centre's third-generation general circulation model (HadCM3) using an evaporation ratio function of the aridity index. The results showed that annual runoff was more sensitive to change in precipitation than to change in evaporation. Simulations using HadCM3 scenarios A2 and B2 indicated that the changes in annual runoff compared to 30-year average runoff for each region, which varied from region to region, ranged from -34.1% to 49.6%. In general, the potential changes in annual runoff were greater in the middle and down reaches of the Yellow River basin. For the Yellow River basin as a whole, the mean annual runoff increased up to 2.2%, 12.3%, and 11.4% for scenario A2, and the changes were 8.4%, -0.1%, and 5.3% for scenario B2 by the years 2020, 2050, and 2080, respectively. However, the increase in future annual runoff will be insufficient to meet projected water demands of the Yellow River Basin. Proper water management and water conservation technologies will need to be considered for the coming century to avoid water shortages. The expected increases in runoff require that more attention will be given to soil and water conservation practices such as vegetation and check-dam construction.