The Yellow River is China's second longest river and originates in the Yueguzonglie Basin in the northern part of the Bayanhar Mountain in Qinghai Province. It runs east for 5,460 km through Qinghai, Sichuan, Chongqing, Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Henan and Shandong before flowing into the Bohai Sea in Shan-dong's Kenli county.

Its branches are the Huangshui, Taohe, Jinghe, Weihe, Luohe, Fenhe, Yihe and Qinhe rivers, and it has an annual runoff of 48 billion cubic meters. Areas that the Yellow River runs through have vast fertile land, natural pastures with plenty of water and lush grass, abundant re-sources, spectacular scenery and rich mineral deposits. The Yellow River Basin and the areas along the tiver in its lower reaches offer more than 20 million hectares of arable land and are home to 110 mllin people.

The Yellow River is generally divided into three parts: the upper reaches, from its origin to Tuoketuo in Inner Mongolia, middle reach-es, from Tuoketuo to Mengjin in Henan, and the lower reaches, from Mengjin to its estuary. In its up-per reaches in the Qinghai-Tibetan Plateau, it enjoys a steady flow and low sand content. Its middle part runs through the Loess Plateau, where mud and sand content in its water increases greatly, making it a real "yellow river." It is unique be-cause 1 cubic meter of its water can have up to 37.6 kg of sand.[1]

Flowing into the North China Plain, it suddenly changes it pace allowing the sand settle and raise the riverbed. This has led to many an expert to call it a "hanging river" in its lower reaches, where its bed can rise up to 10 cm a year. It is thus natural for it to change its flow and course because its bed, silted with sand and mud, is higher than its banks at many places in the lower reaches. Data compiled over the 2,500 years shows the yellow River has broken its banks more than 1,500 times and changed its course in a big way as many as 26 times, creating a massive impact on Tianjin in the north and the area along Huaihe River in the south. Trails of its outflows and course changes can be found everywhere in the North China Plain, and history shows it has caused grave calamities in its lower reaches. "Outflowing flood and widespread bodies," and "starved corpses fill the barren land" that are now part of history books are two of the most vivid descriptions of the disasters it has caused. No wonder, it used to be called the "Sorrow of China."[2]

But despite all this, it indeed is a great river. The torren-tial river has provided for people for generations and given birth to the Yellow River culture, one of the most ancient in the world. The evergreen Yellow River culture has grown and expanded over thousands of years.

After the founding of the People's Republic of China (PRC), the Yellow River entered a new era. A stable society and flourishing economy paved the way for regulating the river and preventing floods. The Chinese government spent huge amounts of money to reinforce the 1,000-li-long banks and diverted its excess water to low-lying areas. Long-term efforts to conserve water and soil in the middle reaches have yielded good results, too. Anumber of hydraulie power projects have been built, bjective conditions permitting, in its middle and upper reaches. They play a significant role in regulating and storing the floodwaters in the lower reaches to generate elec-tricity and provide water for irrigation and drinking. The river has touched its highest points in recent times, fed by trential rain and excessive melting of glacial ice during the past five decades. But despite that no major breaches in its banks or changes in its course have been reported.

The potential to generate hydraulic power from the Yel-low River water is huge. Its 4,600-odd-km-long upper and middle reaches offer abundant opportunity to generate hy-draulic energy. For example, its 1,000-odd-km-long stretch from Longyang Gorge in Qinghai to Qingtong Gorge in Ningxia Hui autonomous region accounts for more than one-third of its water volume, and has a capacity to gener-ate 13 million kW of hydraulic power. That is more than half of the total hydraulic energy generated from its water and makes the stretch ideal for cascade development.

Its stretch from Longyang Gorge to Lanzhou in Gansu has even greater potential. The Longyang and Liujia gorges' hy-dropower stations, both with more than 100-m-high dams, have a reservoir capacity of 26.8 billion and 5.7 billion cubic meters. Other hydropower stations, such as the ones in Bapan Gorge and Yanguo Gorge, have also been built on the river and have a combined installed capacity of 3.1 million km.

Large-scale hydropower facilities in Qingtong Gorge, San-shenggong, Tianqiao and the Sanmen Gorge have been built on its stretch after Lanzhou. The Sanmen Gorge hydropower complex, built near Sanmenxia city in Henan in 1957, was the first large-scale projet on the main course of the Yellow River. The project regulates the floodwaters and eliminates potential threats in the lower reaches. But the reservoir has had to be refurbished many times because improper esti-mates led to seriours deposit of sand in the reservoir. The San-men Gorge hydropower complex generates power and dis-charges floodwaters and silt, and ensures that the reservoir is used for a long time. The lessons learned from the Sanmen Gorge projet has led engineers to take more preautions be-fore buildig large-scale hydropower stations on rivers with high sand content.

To regulate the Yellow River further, a plan for a 5 billion-cubic meter reservoir was initiated in 1994. The project at Xi-aolangdi in Henan, a spot just before the river flows into the North China Plain, has been completed. The Xiaolangdi and Sanmen Gorge reservoirs have helped strengthen flood con-trol measures in the middle and lower reaches of the river.

The chance of a deluge devastating the areas in its middle and lower reaches has been reduced from once in every 50 years to once in 1,000 years. That has earned planners more time to fix the course of the river in its lower reaches and created better conditions for water and soil conservation on the Loess Plateau.

Note: 

[1] The meandering Yellow River on the Ruoergai grassland, Sichuan Province.

[2] Hukou Waterfall in the middle reaches of the Yellow River. The roaring yellow water suddenly falls by 30 m, shaping a spectacular waterfall that resembles water poured from a huge kettle.