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The Yellow River or Huang He / Hwang Ho (|t=|p=}}; , Queen river) is the second-longest river in China (after the Yangtze River) and the sixth-longest in the world at the estimated length of . 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 ancient Chinese civilizations and was the most prosperous region in early Chinese history. But frequent devastating flooding when the silt washed down from the upper reaches elevated the river bed in its lower course higher and higher, sometimes above the level of the surrounding fields, has also earned it the unenviable names "China's Sorrow" and "Scourge of the Sons of Han."
Early Chinese literature refers to the Yellow River simply as He (), the word that has come to mean simply "river" in modern language (in ancient times, however, and were used in the meaning "river"). The first appearance of the name "Yellow River" (黃河) is in the Book of Han () written in the Western Han dynasty (206 BC–AD 9). The name "Yellow River" describes the perennial yellow color of the muddy water in the lower course of the river. The yellow color comes from loess suspended in the water.
Sometimes the Yellow River is poetically called the "Muddy Flow" (|t=|p=}}). The Chinese idiom "when the Yellow River flows clear" is used to refer to an event that will never happen and is similar to the English expression "when pigs fly".
In Qinghai, its Tibetan name is "river of the peacock" (, p maqu 玛曲/瑪曲).
;Mother river, China's Sorrow. Traditionally, it is believed that the Chinese civilization originated in the Yellow River basin. The Chinese refer to the river as "the Mother River" and "the cradle of the Chinese civilization". During the long history of China, the Yellow River has been considered a blessing as well as a curse and has been nicknamed both "China's Pride" () and "China's Sorrow" ().
The river is extremely prone to flooding. It has flooded 1,593 times in the last 3,000–4,000 years, while its main course changed 12 times, with at least 5 large-scale changes from 602 BC to present. Another source says more than 1,500 inundations and 26 changes of course (9 major) in the last 3,000 years. These course changes are due to the large amount of loess carried by the river and continuously deposited along the bottom of the river's channel. This sedimentation causes a natural dam to slowly accrue. Eventually, the enormous amount of waters have to find a new way to the sea, causing a flood in a new valley. Flooding was unpredictable, causing difficulty to farmers.
The river thus changed its pathway in -602. took over the Huai River drainage system throughout the next 700 years. The mud in the Yellow River blocked the mouth of the Huai River and left thousands homeless. The Yellow River adopted its present course in 1897 after the previous course change occurred in 1855. Currently, the Yellow River flows through Jinan, capital of the Shandong province, and ends in the Bohai Sea, yet the eastern terminus for the Yellow River has oscillated from points north and south of the Shandong Peninsula in its many dramatic shifts over time.
The course of the river changed back and forth between the route of the Huai River and the original route of the Yellow River several times over the past 700 years. The consequent buildup of silt deposits was so heavy that the Huai River was unable to flow in its historic course after the Yellow River reverted to its northerly course for the last time in 1897. Instead, the water pools up into Hongze Lake and then runs southward toward the Yangtze River.
The river's floods account for some of the deadliest natural disasters ever recorded. The flatness of North China Plain contributes to the deadliness of the floods. A slight rise in water level means a large portion of land is completely covered in water. When a flood occurs, a portion of the population initially dies from drowning, then by the spread of diseases and the ensuing famine.
The 1887 Yellow River flood in the North China Plain caused an estimated 900,000 to 2,000,000 deaths.
Another historical source of devastating floods is the collapse of upstream ice dams in Inner Mongolia with an accompanying sudden release of vast quantities of impounded water. There have been 11 such major floods in the past century, each causing tremendous loss of life and property. Nowadays, explosives dropped from aircraft are used to break the ice dams before they become dangerous.
Its average discharge is said to be 2,110 cubic meters per second (32,000 for the Yangtze), with a maximum of 25,000 and minimum of 245.
The Yellow River is notable for the large amount of silt it carries—1.6 billion tons annually at the point where it descends from the Loess Plateau. If it is running to the sea with sufficient volume, 1.4 billion tons are carried to the sea annually.
In modern times, since 1972 when it first dried up, the river has dried up in its lower reaches many times, from Jinan to the sea in most years, in 1997 for 226 days. The low volume is due to increased agricultural irrigation, by a factor of five since 1950. Water diverted from the river as of 1999 served 140 million people and irrigated 74,000 km² (48,572 mi²) of land. The highest volume occurs during the rainy season, from July to October, when 60% of the annual volume of the river flows. Maximum demand for irrigation is needed between March and June. In order to capture excess water for use when needed, and for flood control and electricity generation, several dams have been built, but due to the high silt load their life is expected to be limited. A proposed South-North Water Transfer Project involves several schemes to divert water from the Yangtze River, one in the western headwaters of the rivers where they are closest to one another, another from the upper reaches of the Han River, and a third using the route of the Grand Canal.
Due to its heavy load of silt the Yellow River is a depositing stream, that is, it deposits part of its carried burden of soil in its bed in stretches where it is flowing slowly. These deposits elevate the riverbed which flows between natural levees in its lower reaches. Should a flood occur, the river may break out of the levees into the surrounding lower flood plain and adopt a new course. Historically this has occurred about once every hundred years. In modern times, considerable effort has been made to strengthen levees and control floods.
The Yellow River floods for two reasons. First, the North China Plain is extremely flat and there is no natural valley. It has reached the sea at many points from Tianjin to Shanghai except for the mountain region of Shandong. Second, silt from the Loess Plateau makes the river very muddy, which is why the river is called 'yellow'. One estimate gives 34 kilograms of silt per cubic meter as opposed to 10 for the Colorado and 1 for the Nile. Once the river leaves the Shanxi Plateau this silt is deposited in the river bed. Eventually the river bed becomes too shallow and the river is forced to find a new course. People responded by building levees along the banks but silt deposition continued forcing people to build the levees higher. When flood water eventually broke through the levees it could not drain back into the river bed as it would after a normal flood since the river bed was now higher than the surrounding country. The Yellow River delta totals 8,000 square kilometers (3,090 mi²). However, since 1996 it has been reported to be shrinking slightly each year through erosion.
The survey, based on data taken last year, covered more than of the river, one of the longest waterways in the world, and its tributaries.
The Yellow River Conservancy Commission, in 2007 surveyed more than of the river, said 33.8% of the river system registered worse than level five. According to criteria used by the UN Environment Program, level five is unfit for drinking, aquaculture, industrial use and even agriculture.
The report said waste and sewage discharged into the system last year totaled 4.29bn tonnes. Industry and manufacturing made up 70% of the discharge into the river with households accounting for 23% and just over 6% coming from other sources.
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 and total basin area of , 51.4% of the total basin area. Along this length, the elevation of the Yellow River drops 3496 metres, with an average grade of 0.01%.
The source section flows mainly through pastures, swamps, and knolls between the Bayan Har Mountains (巴顏喀啦山脈), 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 Zhaling (扎陵湖) and Lake Eling (鄂陵湖), with capacities of 4.7 billion and 10.8 billion m³ (166 and 381 billion ft3), respectively. At elevations over ) above sea level they are the largest two plateau freshwater lakes in China. A significant amount of land in the Yellow River's source area has been designated as the Sanjiangyuan ("'Three Rivers' Sources") National Nature Reserve, to protect the source region of the Yellow River, the Yangtze, and the Mekong.
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.
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 (57.4 lb/ft3). These sediments later deposit in the slower lower reaches of the river, elevating the river bed and creating the famous "river above ground".
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.
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.
In Kaifeng, the Yellow River is above the ground level.
The Wei River is the largest of these tributaries.
As reported in 2000, the 7 largest hydro power plants (Longyangxia, Lijiaxia, Liujiaxia, Yanguoxia, Bapanxia, Daxia and Qinglongxia) had the total installed capacity of 5,618 MW.
The provinces of Hebei and Henan derive their names from the Huang He. Their names mean respectively "north of the (Yellow) River" and "south of the (Yellow) River".
Major cities located along the Yellow River include, starting from the source, Lanzhou, Yinchuan, Wuhai, Baotou, Luoyang, Zhengzhou, Kaifeng, and Jinan.
Category:Rivers of China Category:Drainage basins of the Pacific Ocean
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