Emptying Hengshan Reservoir to Flush the Sediment Out

Hengshan Reservoir is located in Shanxi Province in Northern China. It has multiple functions in water supply and flood control etc. It also has the first experimental double-curvature arch dam in China. This is a small reservoir on a steep stream. In the first eight years of operation, 24% of the reservoir capacity was occupied by sediment deposits. Flushing, which was undertaken with reservoir emptying in 1974, 1979, 1982 and 1986, was effective in restoring the lost storage capacity and indicated that flushing in every few years will be sufficient to maintain the long term reservoir use. 

In the 250 meters range in front of the dam, the sediment concentration of the flow was measured to be 1,200 kg/m3 and the total flushing time lasted 30 hours. The side slope developed by emptying the reservoir was 0.055. In the middle reach of the reservoir, the mud has very low water content, and it collapsed like Ichthyosis, even there are big chunk of mud floating on the water. In the upstream of the reservoir, the water content was even lower, the sediment deposition looked like crackings of a turtle. With the depth of the main channel being flushed to be higher, more and more mud from the side slope collapsed into the reservoir. 

Da Yu - The First River Engineer of the Yellow River

The Yellow River is the cradle of the Chinese civilization. She has fostered generations of Chinese but she has also brought troubles with her floods. The diligent Chinese people have been struggling to control the river for generations. Da Yu is considered to be the first real river engineer to control the flooding of the Yellow River.

Da Yu was born in the first dynasty of China called Xia Dynasty (夏朝) more than 4000 years ago. His father Gun (鲧) was also a river engineer, who was sentenced to death by the king Shun (舜) because of his failure to control the levee breach of the Yellow River. Da Yu inherited his father's experience, and after much investigation and research, he found the reason for the floods. He thought that the floods damaged the banks in the depressed floodplain areas because of the speed of the flow rushing from its high main channel. He led his fellow workers to dredge the main channel, and let the flow down to the lower area, then he successfully prevented the levee breach and river flooding.

Da Yu worked very hard on the river engineering issues of the Yellow River. He had been working in harnessing the river for 13 years. During these periods he did not go back his home, even 3 times when he passed by the front door of his house. This became a good example of how Chinese people are proud of. The legend about him is in reality a reflection of the ancient Chinese people who struggled against the floods of the Yellow River, but never obeyed their fate to surrender to the nature.

Because of his success in controlling the river,  Da Yu obtained the crown vacated by Shun according to the doctrine of handing the crown to the talented after abdication of the king. But it was Da Yu who passed his power to his own son Qi (启) by establishing the hereditary system. Then Qi founded the Xia Dynasty, the first Chinese dynasty recorded. The statue of Da Yu is being build at Huayuankou (lower reach) of the Yellow River. 

Hyperconcentrated Flow in Sanmenexia Reservoir of the Yellow River (1993) - Part I

After storing water and sediment for several months, Sanmenexia Reservoir in the middle reach of the Yellow River suddenly released water on June 25, 1993. Hyperconcentrated flow was created with a maximum flow discharge at 1,480 m3/s，and the sediment concentration was measured to be 300 kg/m3 for about 24 hours! The water surface elevation dropped from 307.5 m to 294.25 m in the reservoir. This video shows the channel created inside the reservoir by the hyperconcentrated flow.

History of the Yellow River

The Yellow River or Huang He is the second-longest river in China (after the Yangtze River) and the sixth-longest in the world at 5,464 kilometers(3,398 miles). Originating in the Bayankala Mountains in Qinghai Province in western China, it flows through nine provinces of China (Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan,Shandong Provinces) and empties into the Bohai Sea. The Yellow River basin has an east-west extent of 1900 km (1,180 miles) and a north-south extent of 1100 km (684 miles). Total basin area is 752,443 km2 (290,520 mile2).

The headwaters of this mighty river lie in Kunlun Mountains in northwestern Qinghai Province. It runs through nine provinces and autonomous regions on its way to the Bohai Sea. It is not exaggerating to say that Yellow River is a melting port, because there are more than 30 branches and countless streams feeding it through its course. The vigorous upper reaches of the Yellow River starts in Qinghai Province to Hekouzhen in Inner Mongolia. This magnificent river flows quietly, like a shy girl in this section, irrigating the farmlands and nurturing the people. Its middle reaches ends at Taohuayu in Zhengzhou City, Henan Province. Here the Yellow River splits the Loess Plateau in half, forming the longest continuous gorge in the whole drainage area of the river. The Yellow River's lower reaches ends in a delta on the Bohai Sea.

It is agreed upon by almost all the Chinese people that the Yellow River is the cradle of Chinese civilization, the spiritual home of the Chinese people. It is the waters of the Yellow River and its spirit that nurture the whole Chinese nation. For thousands of years, the Yellow River has been admiring by literary giants, artists, as well as by the common people. The Yellow River is not just several letters, nor is it just the name of a yellow-ochre-colored river. It bears special significance: the symbol of the Chinese nation, the spirit of the Chinese people and more importantly, civilization itself.

Neolithic (7,000 BC-3,700 BC), Bronze (3,700 BC-2,700 BC) and Iron Age Sites (770 BC), and so on can be found in the Yellow River's drainage basin, which had been the center of ancient Chinese culture since the Azilian (Middle Stone Age). Here, the story of three cultural heroes: Suiren-shi who taught the Chinese to make fire by drilling wood, Fu Hsi who was the inventor of hunting, trapping and fishing and Shennong-shi who invented agriculture, was spread. It was these three legendary individuals that began the development of civilization in the Yellow River basin. After that, many ancient Chinese emperors, like Emperor Qin Shi Huang, Genghis khan (1162-1227, grandfather of Kublai Khan who is the first emperor of the Yuan Dynasty (1271-1368)) pushed the Yellow River civilization to a wholly new level of refinement, grace and spirituality which drew the attention of the whole world.

A Hyperconcentrated Flood Event of a Tributary of Yellow River (1994/09)

【Introduction】On September 1, 1994, there was a 50-year hyperconcentrated flood event of Beiluo River, tributary of Yellow River at its middle reach in northern China. Flow discharge is around 6,280 m3/s, sediment concentration is 690 kg/m3. Total sediment in 4 days of this event is almost 0.136 billion tons, and total water volume is 2.04 billion m3. This video shows the flood water passing through Daja County, Shannxi Province, China. The flood almost reached the roof of a building here.

Enjoy an Award-winning Song of "Life of the Yellow River"!

【Enjoy】A song "Life of the Yellow River", lyrics by Yiping Chao and the music by Xiaolu Wang. This is a song about keeping the healthy life of the Yellow River, and it has received many awards in China. You can also enjoy the beautiful scenery of the lower Yellow River.

【Lyrics in English】Pentium endless torrents, are your pounding pulse. Traveling through eternal time and space, are the green waves on both banks. Ah, Yellow River, my dear mother, coming along with grand songs, you cast a flow of history. Ah, take care of our mother river and dress her up, we will enjoy the sunshine and green with you together. Ah, love our mother river and repay her, we will sing the hymn of life with you together.

River course changing and levee breaching so many times, should not be your characteristics. River bed running dry again and again, is your silent whispers. Ah, Yellow River, my dear mother, keeping the healthy life of you, is our responsibility as your daughters and sons. Ah, take care of our mother river and dress her up, we will enjoy the sunshine and green with you together. Ah, love our mother river and repay her, we will sing the hymn of life with you together.

An Amazing Bridge in a Hyper-concentrated Flood Event in 1994

【Introduction】On September 1, 1994, there was a 50-year hyperconcentrated flood event of Beiluo River, a tributary of Yellow River at its middle reach in northern China. Flow discharge is around 6,280 m3/s, sediment concentration is 690 kg/m3. Total sediment in 4 days of this event is almost 0.136 billion tons, and total water volume is 2.04 billion m3. This video shows the flood passed through a bridge at Baishui County of the upper reach of Beiluo River. It is really amazing that the bridge can sustain such a huge flood event with a large amount of sediment!

Recent Pictures of the Lower Yellow River in China