Yellow River
China
Earth's Natural Wonders in Asia
Length of River: 3,395miles (5,464 km)
The Yellow River is called "the cradle of Chinese civilization", as its basin is the birthplace of the northern Chinese civilizations and was the most prosperous region in early Chinese history. But frequent devastating flooding largely due to the elevated river bed in its lower course, has also earned it the unenviable name "China's Sorrow".
	Yellow River at Lanzhou[1]

 

The Yellow River or Huang He / Hwang Ho is the second-longest river in China (after the Yangtze River) and the sixth-longest in the world at 5,464 kilometers (3,398 mi).[3] Originating in the Bayan Har Mountains in Qinghai Province in western China, it flows through nine provinces of China and empties into the Bohai Sea. The Yellow River basin has an east-west extent of 1900 km (1,180 mi) and a north-south extent of 1100 km (684 mi). Total basin area is 742,443 km² (290,520 mi²).

The Yellow River is called "the cradle of Chinese civilization", as its basin is the birthplace of the northern Chinese civilizations and was the most prosperous region in early Chinese history. But frequent devastating flooding largely due to the elevated river bed in its lower course, has also earned it the unenviable name "China's Sorrow".

Early Chinese literature refers to the Yellow River simply as He , the word that has come to mean simply "river" in modern language (in anicent times, however, were used in the meaning "river"). The first appearance of the name "Yellow River" is in the Book of Han written in the Western Han dynasty (206 BC–AD 9). The name "Yellow River" describes the perennial ochre-yellow colour of the muddy water in the lower course of the river. The yellow color comes from loess suspended in the water.

Geography

According to China Exploration and Research Society, the source of the Yellow River is at 34 29 31.1N, 96 20 24.6E. The source tribituaries drain into Gyaring Lake and Ngoring Lake high in the Bayan Har Mountains in Qinghai Province in the far west of China. In the Zoige Basin along the boundary with Ganzu Province, the Yellow River loops northwest and then northeast before turning south, creating the "Great Bend", and then flows generally eastward across northern China to the Gulf of Bohai, draining a basin of 752,443 km² (290,520 mi²) which nourishes 120 million people.

The river is commonly divided into three stages. However, different scholars have different opinions on how the three stages are divided.[citation needed] This article adopts the division used by the Yellow River Conservancy Commission.

Upper reaches

The Yellow River, near Xunhua, in Eastern Qinghai. Note the yellowish water, caused by loess.The upper reaches of the Yellow River constitute a segment starting from its source in the Bayan Har Mountains and ending at Hekou County of Inner Mongolia just before it turns sharply to the north. This segment has a total length of 3,472 km (2,160 mi) and total basin area of 386,000 km² (149,035 mi²), 51.3% of the total basin area. Along this length, the elevation of the Yellow River drops 3496 metres, with an average drop of 0.1%.

The source section flows mainly through pastures, swamps, and knolls between the Bayan Har Mountains, and the Anemaqen (Amne Machin) Mountains. The river water is clear and flows steadily. Crystal clear lakes are characteristic of this section. The two main lakes along this section are Lake Bob and Lake Eling , with capacities of 4.7 billion and 10.8 billion m³, respectively. At elevations over 4,260 m (13,976 ft) above sea level they are the largest two plateau freshwater lakes in China.

The valley section stretches from Longyang Gorge in Qinghai to Qingtong Gorge in Gansu. Steep cliffs line both sides of the river. The water bed is narrow and the average drop is large, so the flow in this section is extremely turbulent and fast. There are 20 gorges in this section, the most famous of these being the Longyang, Jishi, Liujia, Bapan, and Qingtong gorges. The flow conditions in this section makes it the best location for hydroelectric plants.

After emerging from the Qingtong Gorge, the river comes into a section of vast alluvial plains, the Yinchuan Plain and Hetao Plain. In this section, the regions along the river are mostly deserts and grasslands, with very few tributaries. The flow is slow. The Hetao Plain has a length of 900 km (560 mi) and width of 30 to 50 km (20–30 mi). It is historically the most important irrigation plain along the Yellow River.

Middle reaches

Yellow River at LanzhouThe part of Yellow River between Hekou County in Inner Mongolia and Zhengzhou in Henan constitutes the middle reaches of the river. The middle reaches are 1,206 km (749 mi) long, with a basin area of 344,000 km² (132,820 mi²), 45.7% of the total, with a total elevation drop of 890 meters (2,920 ft), an average drop of 0.074%. There are 30 large tributaries along the middle reaches, and the water flow is increased by 43.5% on this stage. The middle reaches contribute 92% of the river's silts.

The middle stream of the Yellow River passes through the Loess Plateau, where substantial erosion takes place. The large amount of mud and sand discharged into the river makes the Yellow River the most sediment-laden river in the world. The highest recorded annual level of silts discharged into the Yellow River is 3.91 billion tons in 1933. The highest silt concentration level was recorded in 1977 at 920 kg/m³. These sediments later deposit in the slower lower reaches of the river, elevating the river bed and creating the famous "river above ground". In Kaifeng, the Yellow River is 10 meters (33 ft) above the ground level.

From Hekou County to Yumenkou, the river passes through the longest series of continuous valleys on its main course, collectively called the Jinshan Valley. The abundant hydrodynamic resources stored in this section make it the second most suitable area to build hydroelectric power plants. The famous Hukou Waterfall is in the lower part of this valley.

Lower reaches

Pontoon bridge (Luokou pontoon bridge) over the Yellow River in JinanIn the lower reaches, from Zhengzhou to the sea, a distance of 786 km (488 mi), the river is confined to a levee-lined course as it flows to the northeast across the North China Plain before emptying into the Bohai Sea. The basin area in this stage is only 23,000 km² (8,880 mi²), 3% of the total. The total drop in elevation of the lower reaches is 93.6 m (307 ft), with an average drop of 0.012%.

The silts received from the middle reaches form sediments here, elevating the river bed. During 2,000 years of levee construction, excessive sediment deposits have raised the riverbed several meters above the surrounding ground. Few tributaries add to the flow in this stage; nearly all rivers to the south drain into the Huai River, whereas those to the north drain into the Hai River.[2]