The Yangtze River starts at he Jianggendiru Glacier on the southwestern foothills of the 6,621-m, snow-covered Geladandong, the main peak of the Tanggula Mountains I southwestern Qinghai Province. It flows past Qinghai, Tibet, Yunnan, Sichuan, Hubei, Hunan, Jiangxi, Anhui, Jiangsu and Shanghai, where it empties into the East China Sea. Important cities along the way are Chongqing, Wuhan, Nanjing and Shanghai.

With more than 700 tributaries, the Yangtze River system has a total catchment area of 1.8 million square kilometers, 19 percent of the country?s total area, which mainly lies in the sub-tropical zone. Its tremendous annual flow to the sea averages 1,050,000 million cubic meters, or morethan 20 times that of the Haunghe River.

The upper reaches of the Yangtze River start at its headstream, the Tuotuo River, and goes to Yichang in Hubei Province. The section down the Tuotuo is called the Tongtian River, and the section from Yushu County in Qinghai to Yibin City in Sichuan is called the Jinsha River. The section downstream from Yibin is called the Yangtze River. The flow from the upriver is 46.4 percent of its total. Te section of the Jinsha River in the Hengduan Mountain Area is lined on both banks by numerous mountain canyons. The 3,500-kilometer section from the headstream to Yibin has a descent of more than 6,000 meters, or 90 percent of the total drop of the Yangtze River. Most of the river?s abundant power potential is concentrated in this section, where large hydroelectric power stations can be built in its numerous gorges and canyons. The famed Hutiao or ?Tiger Leaping? Canyon in Lijiang County, Yunnan, one of the world?s largest, is 16 kilometers long with a drop of 170 meters. The canyon itself is 2,500-3,000 meters deep and only 30 meters wide at its narrowest point. At Yibin, the Yangtze River enters the Sichuan Basin, where it is met by the Minjing, Tuojiang, Jialing and Wujiang rivers. Here, the section of the river widens as its voluminous waters rush eastward towards the famous Three Gorges. The Three Gorges, also known as the Yangtze River Gorges, are the Qutangxia, Wuxia and Xilingxia, and cover the 204-kilometer section from Baidicheng in Fengjie, Sichuan to Nanjinguan in Yichang, Hubei, with a drop of 120 meters. Here, the river is hemmed in by the steep rock faces of the peaks of the Wushan Mountains, which, owing to continuous crustal uplifting movement, rear 500-1,000 meters over the river surface. As the Yangtze River cuts its way through the mountains, its bed becomes narrow, less than 100 meters at its narrowest points, forming the magnificent gorges that have drawn tourists fro far and near. The swift and violent current on its steep, narrow bed provides an abundant source of power.

The middle reaches of the Yangtze River Rive cover the section from Yichang in Hubei to Hukou in Jiangxi. From Yichang the river enters the plain, where it becomes much wider and is joined by the Xiangjiang, Zishui, Yuanjiang and Lishui rivers of the Dongting Lake system; the Ganjiang, Fuhe, Xinjiang and Xiushui rivers of the Poyang Lake system; and the Hanshui River, the longest tributary of the Yangtze River. With its numerous tributaries and lakes and large amounts of converging waters, the middle section of the Yangtze River accounts for 47.3 percent of the river?s total runoff. The section of the Yangtze River from Zhijiang in Hubei to Chenglingji in Hunan is known as the Jinjiang, where the numerous bends and shoals can retard flow, obstruct navigation and cause frequent floods. Over the past decades, much has been done to straighten out the convoluted section has been shortened by 80 kilometers.

The lower Yangtze River starts from Hukou to its estuary. Here, the increased flow is only 6.3 percent of the river?s total and the Huangpu is the largest of the few tributaries. The section from Yangzhou to the river mouth used to be known as the Yangtze. In its lower reaches, the Yangtze River is wide and deep: 18 kilometers wide near Nantong, and 80-90 kilometers wide in its outlet to the sea. Nanjing and Hukou along the lower section can be reached by ships of 10,000-ton and 5,000-ton classes respectively. Few large rivers in the world have channels as deep as that of the Yangtze River.

(china.org.cn)