|
The Yellow River (, sometimes simply called the River in ancient Chinese) is the second longest river in China (after Yangtze River) and the fifth in the world. The river is 5464 km long . Originated from the Bayankala Mountains in Qinghai Province in western China, Yellow river flows through nine provinces of China and finally empties into the Bohai Sea. The Yellow River basin has an east-west distance of 1900 km and north -south distance of 1100 km, total basin area 752443 km². The middle stream of Yellow River passes through Loess Plateau with substantial erosion taking place. The large amount of mud and sand discharged into the river makes Yellow River the most sediment-laden river in the world. The recorded highest annual level of silts discharged into the Yellow River is 3.91 billion tons (1933). Highest silt concentration level is recorded in 1977 with 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, Yellow River is forty meters above the ground level. Yellow River is called the "Mother River of China" and "the Cradle of Chinese Civilization" in China, as the Yellow River basin is the birth-place of the northern Chinese civilizations and the most prosperous region in the early Chinese history. However, the frequent devastating flooding, largely due to the elevated river bed in its lower course, has also earned it the unenviable distinction as "China's Sorrow".
Name In the early history, the Yellow River is referred to in Chinese literatures simply as He (河), or "River". The first appearance of the name "Yellow River" (黄河) is in the Book of Han (汉书) written in Western Han dynasty. The name "Yellow River" describes the perennial ochre-yellow colour of the muddy water in the lower course of the river. An alternative poetic name of the river referring to this is the Muddy Flow (). The Chinese expression "when the Yellow River flows clear" is similar to the English expression "when hell freezes over". History and Culture
Characteristics of the Yellow River The Yellow River is notable for the amount of silt it carries, amounting to 1.6 billion tons annually at the point where it descends from the Loess Plateau. If the river is running to the sea with sufficient volume, 1.4 billion tons are carried to the sea. In modern times, since 1972 when it first went dry, the river has gone dry in its lower reaches, from Jinan to the sea, in most years, in 1997 for 226 days. The low volume of the river is due to increased demands on the river for use in irrigation which has increased by a factor of five since 1950. Water diverted from the river by 1999 served 140 million people and irrigated 74000 km² of land. Highest volume occurs during the rainy season, from July to October, when 60% of the volume of the river flows. Water for irrigation, on the other hand, 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 Delta totals 8,000 square kilometers. However, since 1996 it has been reported to be shrinking slightly each year, through erosion. Geography Tracing to a source high up in the Bayankala Mountains in far west of China, the Yellow River loops north, bends south, creating the "Great Bend", and then flows generally eastwards across northern China to the Gulf of Bohai, draining a basin of 752443 km², which nourishes 120 million people. The river is commonly divided into three stages (however, different scholars have different opinions in how the three stages are divided. This article adopts the division by Yellow River Hydrology Committee). Upper reaches The upper reaches of the Yellow River start from the source in the Bayankala Mountains, and end at Hekou County of Inner Mongolia just before it makes a sharp turn to the south. Yellow River in the upper reaches has a total length of 3472 km and total basin area of 386,000 km² (51.3% of total basin area). In the upper reaches, the elevation of Yellow River drops 3496 metres, average drop 1%. The upper reaches can be further devided into three sections: the source section, valley section and the alluvial plain section. The source section mostly flows through pastures, swamps and knolls between Bayankala Mountains and Anemaqen Mountains. The water of the river is clear and flow steady. Crystal clear lakes and sluggish meandering are characteristic in this section. Two main lakes in this section are Zhaling Lake(扎陵湖) and Eling Lake(鄂陵湖), having capacities of 4.7 billion and 10.8 billion m³ respectively. With over 4260 m elevations above sea level, they are the largest two plateau fresh water lakes in China. The valley section is from Longyang Gorge in Qinghai to Qingtong Gorge in Gansu. On the two sides of the Yellow River are steep cliffs. As the water bed is narrow and the average drop is huge, the water flow in this section is extremely turbulent and fast. There are 20 gorges in this section, the more famous ones are Longyang Gorge, Jishi Gorge, Liujia Gorge, Bapan Gorge, Qingtong Gorge. The flow condition in this section makes it the best position to build hydroelectric plants. After emerging from the Qingtong Gorge, the Yellow River comes into alluvial plain section. In this section, the regions along the river are mostly deserts and grasslands. There are very few tributaries in this section. The flow is slow and on both sides of the river there are vast alluvial plains--Yinchuan Plain and Hetao Plain. Hetao Plain has length 900 km and width 30 to 50 km. It is the most important irrigation plain along the Yellow River historically. Middle reaches
Lower reaches In the lower reaches, from Zhengzhou to the sea from a distance of 786 km, the river is confined to a levee-lined course as it flows northeasternly across the North China Plain before emptying into the Bohai Sea. The basin area in this stage is only 23,000 km^2 (3% of total). Total drop in elevation in lower reaches is 93.6 metres, average drop 0.012%. The silts received in the middle reaches sediment in this stage, elevating the river bed. During two thousand years of levee construction, excessive sediments deposits have raised the riverbed several metres over the surrounding grounds. The levee-confined Yellow River received few tributaries in this stage. Nearly all rivers to the south of Yellow River drain into the Huai River, whereas those to the north of it into the Hai River. Tributaries of the Yellow River Hydroelectric power dams on the Yellow River Below is the list of hydroelectric power stations built on the Yellow River (in bracket is the year to start operation): Provinces and cities on the Yellow River Originated from the Bayankala Mountains, the Yellow River now passes nine provinces, namely Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan and Shandong. The mouth of the Yellow River is located at Dongying, Shandong. The provinces of Hebei and Henan derive their names from the Huang He. Their names mean respectively "north" and "south of the (Yellow) River". Major cities located along the Yellow River include (starting from the source): Lanzhou, Wuhai, Baotou, Kaifeng, and Jinan. Flooding and changing of course The river is extremely prone to flooding. It has flooded 1593 times in last 3000-4000 years, while its main course changed 18 times and created some of the highest death tolls in Chinese history. Beginning in 1194, the Yellow River to the north changed its course southwards to run into the Huai River, and changed back and forth several times over the next 700 years. The resulting silting was so heavy that after the Yellow River changed back to its northerly course for the last time in 1897, the Huai He is no longer able to go through its old course. Instead it pools up into Hongze Lake, and then runs southwards towards the Yangtze River. In 1938, during the Second Sino-Japanese War, the Nationalist troops under the orders of Chiang Kai-Shek broke the dike holding back the Yellow River in order to stop the advancing Japanese troops. This resulted in the flooding of an area covering 54,000 km² and the death of 500,000-900,000 people. See also | |||||||||||||||||||||||||||||||
|
| ||||||||||||||||||||||||||||||||
 |
|
| |