The Variable Characteristics and Response to Climatic Factors of the Runoff in the Downstream Areas of the Yellow River under the Background of Global Change

In this paper, the runoff of Huayuankou and Lijin Hydrologic Stations of the downstream areas of the Yellow River from 1951 to 2012 were calculated and analyzed in order to explore the runoff variable characteristics and their response to climatic factors. The following conclusions can be drawn:(1)Annual runoff of the river shows a clear downward trend as a whole, especially in the 1990s, but shifted to increase in the early 21st century.(2)Runoff can be affected by climate change; climatic factors and runoff change in the same time or precedes the latter.(3)The response of runoff to climatic factors is not stable, in other words, changing with time; (4)the response of runoff to precipitation is more sensitive than that of temperature.(5)Precipitation and temperature both contribute to the change of runoff, but the former is a positive contribution and the latter is opposite.