Yellow River

The Yellow River, or Huanghe, is the second longest river in China. Tracing to a source high up the majestic Yagradagze mountain in the nation's far west, it loops north, bends south, and flows east for 5,464 km until it empties into the sea, draining a basin of 745,000 sq km, which nourishes 120 million people. Millennia ago the Chinese civilization emerged from the central region of this basin. [The Yellow River basin is outline in red.]

As the most heavily silt-laden river in the world, the Yellow River got its name from the muddiness of its water, which bears a perennial ochre-yellow color. The river is commonly divided into three stages. In the upper reaches, the river runs through mountainous and arid regions for 3,472 km, ending at Hekouzhen of Inner Mongolia just before it makes a sharp turn to the south.

In the middle reaches, ending at Zhengzhou in Henan province, the river flows south between the Shaanxi and Shanxi Provinces, draining a basin consisting largely of thick deposits of unmodified aeolian loess which is eroded readily by rainfall and wind and accounts for over 90 per cent of the sediment in the main channel downstream. After traversing a 1,206-km course from Hekouzhen to Zhengzhou, the river emerges from narrow mountainous constrictions onto a flat alluvial plain shortly following a sharp turn to the east. The river descends from an altitude of 4,575 m above sea level at the source to 1,000 m at Hekouzhen and 400 m at Zhengzhou.

In the lower reaches, from Zhengzhou to sea for a distance of 786 km, the river is confined to a levee-lined course as it flows northeasterly across the North China plain before emptying into the Gulf of Bohai. During two thousand years of levee construction, excessive sediment deposits have raised the riverbed several meters over the surrounding grounds; it is as much as 10 m above the city level of the ancient capital, Kaifeng, on its southern bank, where the levee embankments are 13 km apart. Nearly all rivers to the south of the levee-protected channel drain into the Huai River system, while those to its north into the Hai River system.