Yellow River - RIVER OF CONSTANT SORROW (Excerpts from News China, Part I)

At 5,464 kilometers in length, the Yellow River contains only two percent of China’s water resources, yet provides water for 12 percent of China’s 1.3 billion population, irrigates 15 percent of its farmland and generates about 14 percent of its GDP. “The Yellow River lacks water resources, and the water supply currently drawn from the river is beyond its capacity,” said Chen Xiaojiang, director of the Yellow River Conservancy Commission (YRCC) of the Ministry of Water Resources in March this year.

The river runs through nine provinces and autonomous regions and empties into the Bohai Bay off the coast of east China’s Shandong Province. For a period in 1972, it failed for the first time to reach the sea, and flow interruptions have regularly been observed since 1987. The annual frequency of “dry days” reached a peak at 226 days for a 704-kilometer section of river in Shandong in 1997. In 1998, the National Development and Reform Commission (formerly the State Development Planning Commission) and the Ministry of Water Resources issued annual water-use quotas and a distribution scheme for the river. These management policies determined total water withdrawals on the basis of hydrology, the need for sediment transport and other ecological factors, and established annual provincial water withdrawals including a seasonal distribution plan for greater withdrawal in the rainy season than in the dry season.

With the authorization of the State Council, YRCC acts as the sole administrator for the allocation of the Yellow River water supply to the nine provinces and autonomous regions through which it flows. In March 1999, the Commission issued the first water withdrawal quota directive and started the water withdrawal control plan for the whole basin. This policy was extended from the main Yellow River to its tributaries in 2006.

According to planning information provided to NewsChina by YRCC, the river's annual water resources that can be tapped is 58 billion cubic meters, and 37 billion cubic meters are allocated to the nine provinces and autonomous regions, with the remaining 21 billion earmarked to wash away silt in the river. The quota for each province and autonomous region is based on their population, economic structure and water demand. A trade in water use rights between various sectors has sprung up in some provinces.

Implementation of these policies has ensured uninterrupted flow of the river to the sea for 14 consecutive years since 2000 and improved the water resource and ecological health of the whole basin. Ecosystem integrity and biological diversity have improved greatly.

A Briefing of the Yellow River in China

【Introduction】The Yellow River (or Huang He) is the second-longest river in Asia after the Yangtze and the sixth-longest in the world at the estimated length of 5,464 km (3,395 mi).Originating in the Bayan Har Mountains in Qinghai province of western China, it flows through nine provinces and empties into the Bohai Sea near the city of Dongying in Shandong province. The Yellow River basin has an east--west extent of 1,900 kilometres (1,180 mi) and a north--south extent of 1,100 km (680 mi). Its total basin area is 742,443 square kilometres (286,659 sq mi). 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. One estimate gives 34 kilograms of silt per cubic meter as opposed to 10 for the Colorado and 1 for the Nile. This video shows the sediment control projects along the Yellow River.

Physical Model Experiment for Bank Regulations of the Lower Yellow River

Physical model experiment was carried out for Huayuankou to Jiahetan reach of the Lower Yellow River. This 103 km long reach is famous for being wandering, with strong depositions occurred often. It’s also called “suspended river” above ground. The braided reach is characterized by a distance of 5 to 20 km between the left and right levees, with a channel width of 1.0 to 3.5 km, and a longitudinal channel slope of 1.72% to 2.65%. The elevation difference between the floodplain and the main channel is relatively small, less than 2.0 m in the reach between Huayuankou and Gaocun. 

This reach is generally quite straight with a sinuosity coefficient of 1.15. In addition, the braided reach is composed of many wide and narrow stretches. In a wide stretch with a long stream length, there are numerous sand bars and complicated branches appearing at low water stages. This kind of planform results in flow diverging and frequent shifting of the main streamline. The channel bed is composed of fine sediment, with non-uniform size distribution ranging from 0.002 mm to 0.18 mm.

The physical model uses a horizontal scale of 1:800, vertical scale of 1:60. Fine residual of burnt coal ash from Zhengzhou Thermal Power Plant was used as the model sediment, with dry bulk density of 0.66 ~ 0.68 t/m³, wet bulk density of 2.1 t/m³. The initial condition of bathymetry was chosen as the field measured data in 2002. The inflow condition was provided by Yellow River Engineering Company of YRCC as a 15-year flow-sediment series from multi-year regulation rules of the Xiaolangdi Reservoir. The first five years was the initial operation period for Xiaolangdi Reservoir, only clear water was released to flush the sediment. The last 10 years was the multi-year sediment regulation when sediment was released only at certain right time during flood. In the proposed river training plans, 14 existing dikes will be still used, plus constructing of 250 new dikes. Each dike is around 1000 m long (200m of warping segment), with the top of the dike being 0.5 m higher than the floodplain. The distance between each dike is around 500 m to 800 m. The objective training width of the reach is set to be 600 m in general. At some curvature locations, this value was loosening to be 1000 m for flood protection purposes. 

The physical model results showed that with the regulation of Xiaolangdi Reservoir, around 80%-90% of the sediment can be regulated to be transported when the flow discharges are greater than 2,500 m³/s during flood season, especially for the year with abundant flow and sediment. The sediment transport ratio can be as high as 90% and above for the man-made flood with the construction of dikes.

Hyperconcentrated Flow in Sanmenxia Reservoir of Yellow River in 1993 (Part II)

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 as the  bank collapsed, sand and silt  falling into the water and develop the hyperconcentrated flow. The hyperconcentrated flow form a channel inside reservoir, and then traveled through the spillway to the downstream. You can also hear the hydraulic engineers discussing the how the channel inside the reservoir developed, as well as the hyperconcentrated flow as they took the video of the bank failures.

Related Post:  Hyperconcentrated Flow in Sanmenxia Reservoir of Yellow River in 1993 (Part I)

Ode to Yellow River (Song in 1975)

Enjoy a song "Ode to Yellow River" by Xinchang Li in 1975 with beautiful scenery of the Yellow River in the upper, middle and lower reaches.

The lyrics are translated as the followings:

Standing on a mountain top, I look at the Yellow River rolling and running towards the southeast.
The stormy billows stirring up lofty high raging waves, 
and the turbid flow forming twist and turn channel. 
It runs from the foot of Kunlun mountain towards the coast of Yellow Sea; 
dividing central China into south and north. 
Ah, the Yellow River! 
You are the cradle of the nation! 
Five thousand years' ancient culture was originated from you; 
and many heroic stories occurred on your side. 
Ah, the Yellow River! 
You are great and strong, like a giant standing on the Asian plain, 
building our nation's protective screen by your heroic body. 
Ah, the Yellow River! 
You flow down miles long, rushing vigorously with thousands of irony arms reaching out toward both the south and north banks. 
The great spirits of our nation will be developed under your feeding. 
The heroic sons and daughters of our homeland will follow your example and 
to be as great as you! 
to be as strong as you!

For information about this song, please see: http://cosmicdinesh.blogspot.com/2012/06/ode-to-yellow-river.html.

The Forming Conditions of Alluvial River Channel Patterns (Part II)

The Forming Conditions of Alluvial River Channel Patterns (Part I)

Happy Spring Festival, Year of Snake!

Today it's the first day of the Chinese New Year, year of SNAKE...Please enjoy the Spring Couplet (a pair of poetry) for the new year.

The first line (to your right) : In the old days, due to the flooding of the Yellow River, people have no means to make a living.The second line (to your left): In nowadays, we have completely harnessed the Yellow River, so people can enjoy a safe and secure life.
The horizontal line (in the middle): Great changes on the Yellow River.