Changes of runoff components in the source region of the Yellow River during the second half of the twentieth century

Abstract

In the 1990s, the runoff volume at Tangnaihai hydrologic station decreased remarkably. The runoff components were separated and climate influences on it were analysed. Researches show that in summers, the decrease in stream flow was mainly caused by the decrease in direct flow, while during fall seasons it resulted from decrease in both base flow and direct flow. For the whole Yellow River study source region, change in precipitation both spatially and temporally was the main contributor to the decrease in runoff and its components.