The Yellow River
The Yellow River or Huang He / Hwang Ho (simplified Chinese: 黄河; traditional Chinese: 黃河; pinyin: Huáng Hé; Mongolian: Hatan Gol, 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 5,464 kilometers (3,395 mi). 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 (河), the word that has come to mean simply "river" in modern language (in ancient times, however, 川 and 水 were used in the meaning "river"). The first appearance of the name "Yellow River" (黃河) is in the Book of Han (simplified Chinese: 汉书; traditional Chinese: 漢書; pinyin: Hàn Shū) 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" (simplified Chinese: 浊流; traditional Chinese: 濁流; pinyin: Zhuó Liú). 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" (Wylie: r Ma chu, 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" (simplified Chinese: 中国的骄傲; traditional Chinese: 中國的驕傲; pinyin: Zhōngguóde Jiāo'ào) and "China's Sorrow"[6] (simplified Chinese: 中国的痛; traditional Chinese: 中國的痛; pinyin: Zhōngguóde Tòng).
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.
Ancient times
Historical maps from the Spring and Automn period and Qin Dynasty (221 - 206 BCE) indicate that the Yellow River at that time flowed considerably north of its present course. These maps show that after the river passed Luoyang it flowed along the border between Shanxi and Henan Provinces then continued along the border between Hebei and Shandong before emptying into Bohai Bay near present-day Tianjin.
The river thus changed its pathway in -602. Major floods in 11 CE are said to be the reason for the fall of the Xin dynasty (9 - 23 CE), when the river once more changed its course from the north, near Tianjin, to the south of the Shandong Peninsula.
According to Tregear, in the 10th century BC one branch followed the present course while a larger one reached the sea near Tianjin by several routes, in 602 BC it shifted to south of Shantung, in AD 70 returned to its present course, in 1048 it moved to Tianjin, in 1324 it returned to south of Shantung, and in 1851 it took its present course.
Medieval times
A major course change in 1194 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.
Recent times
The river gets its yellow color mostly from the fine-grained calcareous silt which originates in the Loess Plateau and is carried in the flow. Centuries of silt deposition and diking has caused the river to flow above the surrounding farmland, making flooding a critically dangerous problem. Flooding of the Yellow River has caused some of the highest death tolls in world history, with the 1887 Huang He flood killing 900,000 to 2,000,000 and the 1931 Huang He flood killing an estimated 1,000,000 to 4,000,000 on the North China Plain.
On June 9, 1938, during the Second Sino-Japanese War, Nationalist troops under Chiang Kai-Shek broke the levees holding back the river near the village of Huayuankou in Henan causing what has been called a "war induced natural disaster." The goal of the operation was to stop the advancing Japanese troops by following a strategy of "using water as a substitute for soldiers" (yishui daibing). The flooding of an area covering 54,000 km² and took some 500,000–900,000 lives while an unknown number of Japanese soldiers were killed. The flood prevented the Japanese army from taking the city of Zhengzhou, but did not stop them from reaching their goal of capturing Wuhan, the city that served as the temporary capital of China at the time.
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.
On 25 November 2008 Tania Branigan of the guardian.co.uk, filed a report China's Mother river, the Yellow River, claiming that severe pollution has made one-third of China's Yellow River unusable even for agricultural or industrial use, due to factory discharges and sewage from fast-expanding cities.
The survey, based on data taken last year, covered more than 8,384 miles of the river, one of the longest waterways in the world, and its tributaries.
The Yellow River Conservancy Commission, in 2007 surveyed more than 8,384 miles 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.
According to China Exploration and Research Society, the source of the Yellow River is at 34 29 31.1N, 96 20 24.6E near the eastern edge of Yushu Tibetan Autonomous Prefecture. The source tribituaries drain into Gyaring Lake and Ngoring Lake on the western edge of Golog Prefecture high in the Bayan Har Mountains in Qinghai Province in the far west of China. In the Zoige Basin along the boundary with Gansu Province, the Yellow River loops northwest and then northeast before turning south, creating the "Ordos Loop", and then flows generally eastward across northern China to the Gulf of Bohai, draining a basin of 752,443 square kilometres (290,520 sq mi) which nourishes 140 million people with drinking water and irrigation.
The river is commonly divided into three stages. These are roughly the northeast of the Tibetan Plateau, the Ordos Loop and the North China Plain. However, different scholars have different opinions on how the three stages are divided. This article adopts the division used by the Yellow River Conservancy Commission.
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 kilometres (2,157 mi) and total basin area of 386,000 square kilometres (149,000 sq mi), 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 4,290 metres (14,070 ft) 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.
Yellow River at Lanzhou
The part of the Yellow River (see Ordos Loop) between Hekou County, Inner Mongolia 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 square kilometres (133,000 sq mi), 45.7% of the total, with a total elevation drop of 890 metres (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 (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.
In the lower reaches, from Zhengzhou to the sea, a distance of 786 kilometres (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 square kilometres (8,900 sq mi), a mere 3% of the total, because 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. The total drop in elevation of the lower reaches is 93.6 metres (307 ft), with an average grade 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.
In Kaifeng, the Yellow River is 10 metres (33 ft) above the ground level.
Il Fiume Giallo
Il Fiume Giallo (in cinese: Caratteri cinesi semplificati: 黄河; Caratteri cinesi tradizionali: 黃河; pinyin: Huáng Hé) è il principale fiume della Cina settentrionale e in assoluto il 2° del paese dopo il Fiume Azzurro, con una lunghezza totale di circa 5.464 km e un bacino di raccolta ampio circa 745.000 km quadrati.
Il fiume Giallo nasce nella parte nord della Cina a sud del Deserto di Gobi nella provincia del Qinghai dalle montagne Kunlun, conosciuto con il nome tibetano di Ma Chu.
Gli abbondanti materiali giallastri che il fiume trascina con sé non sono altro che sedimenti fertili raccolti dalle acque durante il percorso attraverso gli altipiani ricoperti di loess, giustificando così la denominazione di Fiume Giallo.
Proprio per questa sua particolarità le acque del fiume risultano estremamente "pesanti" e fangose tanto da rendere lo stesso particolarmente impetuoso e distruttivo durante le piene stagionali.
Affluenti:
Baihe (Fiume Bianco)
Ejin (Fiume Nero)
Fiume Fen
Fiume Wei
Fiume Luo
Il Fiume Giallo con la sua caratteristiva pensile (più alto dei terreno adiacente) è stato non solo, la culla della civiità, ma anche la causa di grandi disastri. La sua conformazione sopraelevata rispetto al terreno circostante, nel corso dei secoli, ha provocato spaventose inondazioni di centinaia di chilometri in una sconfinata zona. Il fiume trascina grande quantità di limo proveniente dal ” Loess”, che nelle sue tracimazioni rende il terreno di una fertilità eccezionale e per anni consecutivi coltivabile senza bisogno di fertilizzanti, si capisce perchè queste terre siano state i più antichi centri dell’agricoltura e civiltà cinese. E’ un fiume distruttore ma anche fecondatore nel medesimo tempo. La leggenda vuole che le Divinità premiarono un uomo eccezionale affogato nel fiume con il titolo di ” Conte ” e lungo il suo corso una volta l’anno, in alcune località, gli venivano offerte delle giovani vergini in sposa, per cattivarsene la benevolenza. 11 Conte dei Fiume era il testimone che garantiva la sincerità dei giuramenti, alleanze, correttezza nei contratti d’affari. Tra le antiche figure di sovrani nel terzo milienio avanti Cristo emerse: ” YU ” il grande ingegnere che riuscì a imbrigliare le acque dei ” Fiume ” come anticamente era chiamato, con opere di controllo idrico che resero irrigui i campi e li posero al riparo dalle inondazioni. YU fu il fondatore della ” Dinastia Xia “. Domare le acque, creare il loro deflusso verso il basso, senza tracimare stavano ad indicare il ” buon governo e che il Figlio dei Cielo godeva dei favore divino. Il pensatore, filosofo Mencio 4′ - 3′ secolo A. C. ricordava la Grande Alluvione e l’opera di YU. I cinesi si servirono di un esteso sistema di canali sia per l’irrigazione dei campi che per le comunicazioni e il trasporto delle merci. Il fiume è chimato dai cinesi anche: L’indomabile.
