2.4 Data sources
The source region of the Yellow River refers to the region from the headwater of the river to the Tangnaihai hydrometric station. It is a unique geographical location, which makes it the most important water-contributing region in the Yellow River Basin. It is also known as the “water tower” of the river (Figure 1). The Tangnaihai hydrometric station monitors a basin area of 1.22 × 105km2. The area has an average annual runoff of 2.051 × 1010 m3. This station plays a critical role in monitoring and regulating the flow of the Yellow River. This paper analyzed the annual runoff and sediment discharge data measured at the Tangnaihai station during 1960-2013, as illustrated in Figure 2.
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