Ruo Shui
Encyclopedia
Ruo Shui is a large river of northern China
. It flows approximately 630 kilometres (391.5 mi) from its headwaters in the Qilian Mountains north-northeast into an endorheic valley in the Badain Jaran Desert
. The river forms one of the largest inland delta
s or alluvial fan
s in the world. Its drainage basin
covers about 78600 square kilometre in parts of the Chinese provinces of Gansu
and Inner Mongolia
.
, picking up several tributaries from the south. For the first 150 kilometres (93.2 mi) its water is used to irrigate fields along its valley. It then turns north-northeast, flowing out into the desert, and becoming a losing stream
as its water sinks into the surrounding earth.This quality is what gives the river its name, as it greatly lessens the flow and even causes it to dry up in some years. From the turn it runs about 175 kilometres (108.7 mi) in that direction onto a vast alluvial plain formed by the river's sediment deposits. This part of the river is also known as the Etsin Gol or Etsin River. At Ximiao, the river splits into two ephemeral distributaries called the Dong He (東河, eastern river) and the Xi He (西河, western river), each about 220 kilometres (136.7 mi) long, draining into the Juyan Lake Basin
. The Dong empties into a lake called Sogo Nur, while the Xi river empties into a seasonal basin called the Gaxun Nur.
, a valley which once formed a significant portion of the Silk Road
. The upper section of the river (Heihe) was first settled by the Chinese in about 100 B.C. Many outposts were created to protect Silk Road traders from the frequent attacks of barbarian
s, as the water-abundant valley of the river in relation with the aridity of the surrounding terrain provided an easy route for Huns and Mongols to launch raids. Since then, the river valley has been intensely cultivated and logged. However, clearing of the landscape has caused increased erosion, leading to desertification
of the region and a gradual reduction of the river flow.
The lower part of the river was once confused to be the middle reach of the Yellow River
, which lies farther east but flows for a significant distance in the same direction paralleling the Ruo River.
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. It flows approximately 630 kilometres (391.5 mi) from its headwaters in the Qilian Mountains north-northeast into an endorheic valley in the Badain Jaran Desert
Badain Jaran Desert
The Badain Jaran Desert is a desert in China which spans the provinces of Gansu, Ningxia and Inner Mongolia. It covers an area of 49,000 sq. kilometers ....
. The river forms one of the largest inland delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...
s or alluvial fan
Alluvial fan
An alluvial fan is a fan-shaped deposit formed where a fast flowing stream flattens, slows, and spreads typically at the exit of a canyon onto a flatter plain. A convergence of neighboring alluvial fans into a single apron of deposits against a slope is called a bajada, or compound alluvial...
s in the world. Its drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
covers about 78600 square kilometre in parts of the Chinese provinces of Gansu
Gansu
' is a province located in the northwest of the People's Republic of China.It lies between the Tibetan and Huangtu plateaus, and borders Mongolia, Inner Mongolia, and Ningxia to the north, Xinjiang and Qinghai to the west, Sichuan to the south, and Shaanxi to the east...
and Inner Mongolia
Inner Mongolia
Inner Mongolia is an autonomous region of the People's Republic of China, located in the northern region of the country. Inner Mongolia shares an international border with the countries of Mongolia and the Russian Federation...
.
Geography
The river rises as the Heishui (黑水, black river) on the north slopes of the Qilian Mountains roughly 75 kilometres (46.6 mi) southeast of Minle. It flows north then northwest past ZhangyeZhangye
-Administration:Zhangye has 1 urban district, 4 counties, 1 autonomous county, 97 towns, and 977 villages.-Demographics:Zhangye has a total population of 1,260,000, only 260,000 being urban residents...
, picking up several tributaries from the south. For the first 150 kilometres (93.2 mi) its water is used to irrigate fields along its valley. It then turns north-northeast, flowing out into the desert, and becoming a losing stream
Losing stream
A losing stream, or influent stream, is a stream or river that loses water as it flows downstream. The water infiltrates into the ground recharging the local groundwater, because the water table is below the bottom of the stream channel...
as its water sinks into the surrounding earth.This quality is what gives the river its name, as it greatly lessens the flow and even causes it to dry up in some years. From the turn it runs about 175 kilometres (108.7 mi) in that direction onto a vast alluvial plain formed by the river's sediment deposits. This part of the river is also known as the Etsin Gol or Etsin River. At Ximiao, the river splits into two ephemeral distributaries called the Dong He (東河, eastern river) and the Xi He (西河, western river), each about 220 kilometres (136.7 mi) long, draining into the Juyan Lake Basin
Juyan Lake Basin
The Juyan Lake for western lake, Sogo Nuur for eastern lake) is a former lake in the Gobi desert of western Inner Mongolia at the Alxa League near the border of eastern Xinjiang. Goshun Nur had an area of in 1958, of in 1960, and has dried up in 1961....
. The Dong empties into a lake called Sogo Nur, while the Xi river empties into a seasonal basin called the Gaxun Nur.
Delta
The Ruo River has created over the past few million years one of the largest inland river deltas or alluvial fans in the world. Sediments deposited by the river span across a massive area 300 kilometres (186.4 mi) long and 200 kilometres (124.3 mi) across. The delta is crossed by hundreds of dry channels entrenched by the river during its frequent course changes. Because the climate of the area has followed a drying trend over the past 10,000 years or so, the delta is no longer considered active (i.e. deposits are not being built up significantly) and is slowly being eroded by wind and water action.History
About 2,000 years ago, the river was said to have a much more abundant flow than it does today and thus its perennial reaches stretched much farther out into the desert than it does today. Parts of the river flow through the Hexi CorridorHexi Corridor
Hexi Corridor or Gansu Corridor refers to the historical route in Gansu province of China. As part of the Northern Silk Road running northwest from the bank of the Yellow River, it was the most important route from North China to the Tarim Basin and Central Asia for traders and the military. The...
, a valley which once formed a significant portion of the Silk Road
Silk Road
The Silk Road or Silk Route refers to a historical network of interlinking trade routes across the Afro-Eurasian landmass that connected East, South, and Western Asia with the Mediterranean and European world, as well as parts of North and East Africa...
. The upper section of the river (Heihe) was first settled by the Chinese in about 100 B.C. Many outposts were created to protect Silk Road traders from the frequent attacks of barbarian
Barbarian
Barbarian and savage are terms used to refer to a person who is perceived to be uncivilized. The word is often used either in a general reference to a member of a nation or ethnos, typically a tribal society as seen by an urban civilization either viewed as inferior, or admired as a noble savage...
s, as the water-abundant valley of the river in relation with the aridity of the surrounding terrain provided an easy route for Huns and Mongols to launch raids. Since then, the river valley has been intensely cultivated and logged. However, clearing of the landscape has caused increased erosion, leading to desertification
Desertification
Desertification is the degradation of land in drylands. Caused by a variety of factors, such as climate change and human activities, desertification is one of the most significant global environmental problems.-Definitions:...
of the region and a gradual reduction of the river flow.
The lower part of the river was once confused to be the middle reach of the Yellow River
Yellow River
The Yellow River or Huang He, formerly known as the Hwang Ho, is the second-longest river in China 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...
, which lies farther east but flows for a significant distance in the same direction paralleling the Ruo River.