Yangzi

I

Introduction

Yangzi or Yangtze, also Chang Jiang, longest river of Asia, in China, about 6,300 km (3,900 mi) in length. It rises in the Kunlun Mountains in the south-western section of Qinghai (Tsinghai) Province, and flows generally south through Sichuan (Szechwan) Province into Yunnan (Yün-nan) Province, where, in the vicinity of the town of Huize (Hui-tse), it bends sharply to the north-east. Then, it flows generally north-east and east across central China through Sichuan, Hubei (Hu-pei), Anhui (An-hui), and Jiangsu (Kiangsu) Provinces to its mouth in the East China Sea, about 23 km (14 mi) north of Shanghai.

Although the entire river (jiang) is known as the Yangzi to foreigners, the Chinese apply that designation only to 645 km (400 mi) or so of its course, the portion traversing the region identified with the Yang kingdom (flourished about 10th century bc). From its upper reaches to Yibin, the river is called the Jinsha (Chin-sha), or “Golden Sand”, and various other names are applied in the provinces it traverses. The official name for the entire river is Chang Jiang (Chang Kiang), or “Long River”.

II

Course of the Yangzi

The headwaters of the Yangzi are situated at an elevation of about 4,900 m (16,000 ft). In its descent to sea level, the river falls to an altitude of 305 m (1,000 ft) at Yibin (I-pin), Sichuan Province, the head of navigation for river boats, and to 192 m (630 ft) at Chongqing (Chungking). Between Chongqing and Yichang (I-ch'ang), at an altitude of 40 m (130 ft) and for a distance of about 320 km (200 mi), it passes through the spectacular Yangzi Gorges, which are noted for their natural beauty but are dangerous to shipping. Yichang, 1,600 km (1,000 mi) from the sea, is the head of navigation for river steamers; ocean-going vessels may navigate the river to Hankou (Hankow), a distance of almost 1,000 km (600 mi) from the sea. For about 320 km (200 mi) inland from its mouth, the river is virtually at sea level.

III

Flooding

More than 1,683,500 sq km (650,000 sq mi) of territory are drained by the Yangzi and its branches. The principal tributaries are the Han, Yalong (Ya-lung), Jialing (Chia-ling), Min, and Tuo He (T'o Ho), on the north and on the south, the Wu; at Zhenjiang (Chinkiang), the Grand Canal links the Yangzi to the Huang He (Huang Ho). During periods of heavy rains, lakes Dongting (Tung-t'ing) and Poyang receive some of the overflow of the Yangzi. Despite these outlets, floods caused by the river have occasionally caused great destruction of life and property. In the 20th century, devastating floods occurred in 1905, 1980, and 1981. In July 1995, floods described as being of a “once in a hundred years” severity, and caused by the melting of usually permanent snow in the Yangzi's mountain headwaters, caused more than 1,200 deaths. Just three years later torrential rain caused the worst floods in over 40 years. The death toll for the flooding, which lasted the three months from June to August, was over 3,000 people.

IV

Three Gorges Dam Project

It was partly to address the problem of flooding, as well as China's deficiency in electricity generation, that led the Chinese authorities to begin building the massive, and hugely controversial, Three Gorges Dam. Situated at Sandouping, the dam, scheduled for completion by 2009, will be 185 m (606 ft) high, holding a reservoir 1,084 sq km (419 sq mi) in area. Twenty-six generators at the dam will produce a total of 18,200 megawatts of electricity, the largest hydroelectric facility in the world. When complete it is estimated that this single dam will meet 10 per cent of China's electricity needs. It is also claimed by the Chinese government that it will reduce flooding on the Yangzi, which regularly causes considerable loss of life and devastation to property.

The reservoir behind the dam will be approximately 600 km (375 mi) long. This will mean the displacement of between 1 and 2 million people, who will need to be relocated from more than 150 towns and villages that will be inundated or partially inundated by the reservoir. In addition to this, there is the loss of countless cultural, religious, and archaeological sites, and huge environmental damage. Because of the concerns over the massive human and environmental costs of the project, neither the United States nor the World Bank have become involved.

In 2001 another plan to tame Yangzi floods was announced by China and the United Nations Development Programme (UNDP). The project is aimed at the reconstruction of lakes and wetlands in the middle and lower reaches of the river, in order to increase its capacity to retain water. The plan is designed to reduce damage caused by overgrazing and deforestation, which prevent grasslands and forests from storing excess water, and to protect against erosion, which results in the deposition of sediment and silt in the river basin. The US$27-million project was launched in 2003, after being approved by the UN Global Environment Facility.