The Yangtze River is the longest river in China, stretching 3,917 miles (6,304 km) from end to end. It is the third longest river in the world after the Nile in Africa (4,130 mi/6,650 km) and the Amazon in South America (3,976 mi/6,400 km), and is slightly longer than the Mississippi River system in North America (3,902 mi/6,280 km). It is unique among the world’s longest rivers in that its entire length, from its remote mountainous source to where it meets the sea, is contained within the borders of a single country.
The Yangtze originates in the mid-western part of the country, high on the Tibetan Plateau in the Tanggula Mountains where runoff from melting glaciers meets various streams and inflows to form the fledgling river. At elevations of nearly 16,000 feet (4,878 meters), the river runs through narrow valleys whose rocky sides are too steep to be easily traversed. These remote regions are sparsely populated, and the few villages that can be found are situated high above the river in the mountains. At this stage, the largest inflows come from the Yalong River. The Yangtze continues to gain both speed and volume as it rushes from the highlands down to an elevation of 1,000 feet (305 meters) above sea level, eventually reaching the Three Gorges area before widening out into the eastern plains through a series of lakes, marshes, and channels in the provinces of Hunan and Hubei. The city of Wuhan (population 11 million) sits on the Yangtze at this point, just before the river descends into Jiangxi province and feeds Lake Poyang, the country’s largest natural freshwater lake. As the water leaves the lake it turns northeastward and flows into the southern part of the North China Plain before finally reaching its end at the East China Sea near the city of Shanghai (population 25 million).
Roughly one third of China’s population lives in the Yangtze basin, which extends 2,000 miles (3,218 km) east-west and 600 miles (966 km) north-south. Due to harsh conditions at its upper reaches, the population there is particularly sparse, consisting mainly of ethnic Tibetans engaged in traditional farming. However, far along at its opposite end, the Yangtze River delta has the highest population density in the entire country. Almost half of China’s total crops, including a majority of its rice, are grown in the Yangtze basin. The river also serves as a vast fishery, hosting 30 economically significant species that fuel a large fishing industry. As China’s main navigable waterway, the Yangtze facilitates travel and trade along its length. Historically, ocean-going ships of up to 3,000 tons have been able to sail deep into the country’s interior via the Yangtze, and the river allows the transportation of domestic cargo between major cities such as Wuhan, Nanjing and Chongqing.
Throughout its history, the middle and lower Yangtze basin has been prone to devastating floods. Since large portions of the river pass through steep mountainous areas, rainfall is channeled directly into the river without being absorbed into the surrounding landscape. Excessive flooding often occurs during the rainy season, depending on seasonal precipitation. During the 20th century alone the river flooded catastrophically three times (in 1931, 1954 and 1998). These floods killed millions of people and left as many as 40 million people homeless in their wake. The 1931 event was particularly damaging, killing upwards of a million people.
Proposals to dam the Yangtze River date back more than 150 years. Initially, plans focused on flood control and irrigation, but after the advent of hydroelectric power in the late 1800s, the focus shifted toward electricity generation as a primary goal. While Chinese officials determined in the 1950s that a large dam in the Three Gorges area would be well-suited to the cause, it was not until 1992 that the government approved construction of the project. Construction on the Three Gorges Dam began in 1994, and when it was fully completed in 2012 was the largest electricity-generating power plant in the world, with a capacity of 22,500 megawatts. The project cost an estimated $25-$40 billion and required a team of 25,000 workers, ten million tons of concrete, and two million tons of steel to complete.
In addition to being China’s single largest source of electric power, the dam also allows for flood control. By holding water in its reservoir that would have otherwise flowed straight downstream–and then gradually releasing it later–flooding events have been reduced. (The system is far from perfect, however. In 2020, higher than expected rainfall during the summer monsoon season resulted in floods that killed 141 people.) River navigation improved as well.. Before the dam was built, ships of up to 3,000 tons were able to travel up the river as far as Chongqing, nearly 1,000 miles from the sea. However, rapids and shallows made navigating the waterway’s upper reaches treacherous. Due to the deep reservoir created behind the dam and a new series of locks, ships of up to 10,000 tons are now able to travel safely upriver in deep, slower moving water. The annual amount of cargo transported via the river tripled once the dam’s lock system was completed.
While by many measures construction of the dam has been a success, critics suggest that these improvements have been offset by social and environmental disruptions. Once filled, the dam’s reservoir submerged over 150 existing cities and towns and forced the relocation of 1.3 million people. International observers considered this forced removal of people a violation of their human rights. A further 100,000 people are expected to require relocation as a result of landslides around the bank of the reservoir. Such landslides and other natural disasters in the area have gone up by 70 percent since the dam was built. Additionally, the reservoir submerged hundreds of factories and waste dumps whose remnants contaminate the water. This was further compounded by free-floating garbage and sewage from the now-underwater cities. All of this pollution is contained within the reservoir and is unable to flush itself out as it would if the river were free-flowing. Similarly, soil runoff delivers large amounts of silt and sediment into the reservoir. Environmentalists point out that the sediment contains vital nutrients that had for millennia nourished plant and animal life downriver, but now that sediment is trapped behind the dam. The gradual accumulation of silt also reduces the total capacity of the reservoir. It is likely that decades in the future the flood control benefits of the dam will be undercut as the silt displaces the water. Additionally, various species of plants and animals, some already endangered at the time of the dam’s construction, have seen their numbers reduced even further. The Yangtze River Dolphin was declared extinct in 2006, its disappearance hastened by the habitat reduction caused by the dam and its reservoir.
Despite these controversies, the Yangtze River as a whole remains a vital part of China’s economic and cultural life. Like many of the world’s great rivers, it is a patchwork of different terrain, populations, and functionalities. At its most remote point it runs cold and rugged with only a few small villages scattered along its path, while near its mouth it supports the life and livelihood of millions of people both urban and rural.
References
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