Effects of Climate/Land Surface Changes on Streamflow With Consideration of Precipitation Intensity and Catchment Characteristics in the Yellow River Basin

The climate elasticity of streamflow is an important indicator for quantifying the contributions of climate/underlying surface changes to streamflow, but precipitation intensity and catchment characteristics are usually ignored. In this study, the effects of precipitation amount (P), precipitation intensity (i), potential evapotranspiration (ET0), and multiple catchment characteristics parameters (including parameter n of the Choudhury-Yang equation and vegetation leaf area index, LAI) on naturalized streamflow were estimated for the Yellow River Basin of China using elasticity of streamflow. The results showed that the naturalized streamflow was most sensitive to ET0, followed by P and i in terms of climate elasticity. The factors responsible for the decrease in naturalized streamflow in 2001-2010 relative to 1961-2000 varied across the basin. Factors i and ET0 played the most important roles in the headwaters and were responsible for 27.0% and -82.7% of the absolute streamflow change. The dominant factors were P (-17.6% to -12.5%), ET0 (-19.2% to -14.4%), and LAI (-22.9% to -14.0%) in the middle-lower subbasins. The contributions of parameter n and LAI were similar in the headwaters, but the contribution of LAI became relatively large in the downstream. The physical meaning of n, which has not been clearly identified, was discussed in this study. The annual n was correlated well with the sum of evapotranspiration and terrestrial water storage, which represents the water both stored in the ground and evaporated into the air. The findings of this study can provide guidance for the river basin water resource management.