The Yellow River is the second longest river in China and the cradle of Chinese civilization as the Nile is the cradle of Egyptian civilization. It originates in Tibet---like the Yangtze, China's largest river, and the Mekong River---and gets nearly 45 percent of its water from glaciers and vast underground springs of the Qinghai-Tibet plateau. From Tibet, it flows for 5,464 kilometers (about 3,400 miles) through Qinghai, Gansu, Ningxia, Inner Mongolia, the border of Shaanxi and Shanxi, Henan and Shandong before it empties into Bo Hai Gulf in the Yellow Sea.
The Yellow River is known as the Huang in China. It is slow and sluggish along most of its course and some regard it as the world's muddiest major river, discharging three times the sediment of the Mississippi River. It gets its name and color from the yellow silt it picks up in the Shaanxi Loess Plateau. The Yellow River flows in braided streams, a network of smaller channels that weave in and out of each other. In each channel silt slowly builds the riverbed above the surrounding landscape and gives the river its devastating habit of breaking its banks and changing course,
The Yellow River is vital to making northern China inhabitable. It supplies water to 155 million people, or 12 percent of the Chinese population, and irrigates 18 million acres---15 percent of China's farmland. More than 400 million people live in the Yellow River basin. Agricultural societies appeared on its banks more than 7,000 years ago. Web Sites: Wikipedia Wikipedia University of Massachusetts U Mass Yellow River Conservancy Commission Yellow River Conservancy Commission.Yellow River Floods: Sometimes called the "River of Sorrow," the Yellow River is one of the world's most dangerous and destructive rivers. Since historians began keeping records in 602 B.C., the river has changed course 26 times and produced 1,500 floods that have killed millions of people. The root of these disasters is a large amount of silt generated by soil erosion.
From time to time the Yellow River overflows its banks and fills huge plains with large amounts of water. Floods sometimes occur when blocks of ice block the Yellow River. About once a century these floods reach catastrophic levels.
When the levees of the Yellow River break, which happens with some regularity, the countryside is devastated. When the river's dikes were breached in 132 B.C., floods occurred in 16 districts and a new channel was opened in the middle of the plain. Ten of millions of peasants were affected. The break remained for 23 years until Emperor Wu-ti visited the scene and supervised its repair.
In A.D. 11, the Yellow River breached its dikes near the same place, and the river changed course and forged a new path to the sea, a hundred miles away from its former mouth. Repair work took several decades.
In a tactic intended to halt the southward movement of Japanese soldiers from Manchuria before World War II, Chiang Kai-shek ordered his soldiers to breach the levees of the Yellow River and purposely divert its flow. At least 200,000, maybe millions, died, millions more were made homeless and the Japanese advanced anyway.
Sometimes when the Yellow River floods it becomes like a flowing mudslide. The river normally carries an enormous amount of silt and the amount increases when it floods. During a 1958 flood sediment levels were measured at 35 pounds per square foot, causing the river surface to become “wrinkled.
Rising Yellow River and Silt: Each year 1.5 billion tons of soil flows into the Yellow River. Sometimes there is so much sediment in the river it looks like chocolate milk. Three-fourths of this silt ends up in the Yellow Sea, with the remainder settling in the river beds, causing the level of the river to rise. Over the centuries the river has risen between 15 and 40 feet above the surrounding plains, in some cases with silt blocking off natural drainage channels and making areas more prone to flooding.
Technical problems posed by a large amount of silt and the rising water levels include: 1) the need to build higher and higher levees; 2) the need to continuously dredge large amounts of silt; 3) creating channels to release floods; and 4) building of dams to control floods. Dam building presents its own problems. The reservoir behind the Soviet-designed Yellow River dam built at Sanmenxia in 1960 silted up after only two years.
To hold the river back and prevent floods, the Chinese have built 800 kilometers of levees. Some of the levees are huge. Because water levels in the river rise every year, the levees also have to be raised. In many places, the river has sat above the surrounding landscape for some time. The journalist Edgar Snow wrote in 1961: "The riverbed [is] twenty to twenty-five feet above the surrounding countryside. I have watched junks sail overhead at that height."
Today, the Yellow River is above the landscape for much of its last 500 miles to the sea and the river continues to rise at an alarming rate of four inches a year. If a levee breaks, larger tracts of the countryside are vulnerable to flooding.
