Response of Streamflow to Climate Changes in the Yellow River Basin, China

Abstract

limate changes impact hydrological processes and control streamflow at the basin scale. The present study was conducted to investigate the impact of climate change on streamflow in the Yellow River basin (YRB), China. The temporal trends of streamflow were explored by the Mann?Kendall method and a linear fit model, and the relationships between streamflow, precipitation, and potential evapotranspiration (ETp) were investigated. Furthermore, the contribution of climate changes to streamflow was revealed by Budyko?s method and a simple water balance model. The following results were obtained: (i) decreasing abruptness in streamflow occurred in 1990, and this date was used to divide the streamflow into two periods (baseline period and period of change); (ii) 67 of 80 stations showed decreasing trends with an average reduction of 10.37% of annual precipitation changes, while most of the stations displayed increasing trends with a 3.71% increase in annual ETp; (iii) the precipitation and ETp elasticity of streamflow, as expected, revealed that streamflow increases with increasing precipitation, whereas it decreases with increasing ETp; and (iv) the changes of precipitation and ETp reflected complementary effects on the reduction of streamflow from the baseline period to the period of change, the decreasing trend in precipitation being the main cause for the reduction of streamflow, but the declining rates of ETp causing a slight increase in streamflow.