# Red River (Asia)

The Red River, also known as the Hong River (traditional Chinese: 紅河; simplified Chinese: 红河; pinyin: Hóng Hé; Vietnamese: Sông Hồng; Chữ Nôm: 瀧紅) and Sông Cái (lit. "Main River"; Chữ Nôm: 瀧丐) in Vietnamese, and the Yuan River (元江, Yuán Jiāng) in Chinese, is a 1,149-kilometer (714 mi)-long river that flows from Yunnan in Southwest China through northern Vietnam to the Gulf of Tonkin. According to C. Michael Hogan, the associated Red River Fault was instrumental in forming the entire South China Sea at least as early as 37 million years before present. The name red and southern position in China are associated in traditional cardinal directions. The river is relatively shallow, and carries a lot of reddish silt along its way, appearing red brown in colour.

## Geography

The Red River begins in China's Yunnan province in the mountains south of Dali. Main headstreams Leqiu River, Xi River and Juli River confluence at Nanjian where they form the Lishe River. The Lishe River meets with another headstream, the Yijie River at Hongtupo, Chuxiong Prefecture. It flows generally southeastward, passing through Yi and Dai ethnic minority areas before leaving China through Yunnan's Honghe Autonomous Prefecture. It enters Vietnam at Lào Cai province and forms a portion of the international border between China and Vietnam. The river, known as Thao River for this upper stretch, continues its southeasterly course through northwestern Vietnam before emerging from the mountains to reach the midlands. Its main tributaries, the Black River (Da River) and Lô River join in to form the very broad Hồng near the city of Việt Trì, Phú Thọ province.
Downstream from Việt Trì, the river and its main distributaries, the Đuống River, Kinh Thầy River, Bạch Đằng River and the Thái Bình river system spread out to form the Red River Delta. The Red River flows past the Vietnamese capital Hanoi before emptying into the Gulf of Tonkin. Its estuary is an important Ramsar site and forms the main part of the Xuân Thủy National Park.
The reddish-brown heavily silt-laden water gives the river its name. The Red River is notorious for its violent floods with its seasonally wide volume fluctuations. Intense seasonal floods are made worse by erosion, development, and pollution. The delta is a major agricultural area of Vietnam with vast area devoted to rice. The land is protected by an elaborate network of dikes and levees.

## As a travel and transportation route

In the 19th century, the Red River was thought to be a lucrative trade route to China. The late 19th-century French explorers were able to travel up the Red River until Manhao in South Yunnan, and then overland toward Kunming.
The Red River remained the main commercial travel route between the French Indochina and Yunnan until the opening of the Kunming–Haiphong Railway in 1910. Although French steamers would be able to go as far upstream as Lao Cai during the rainy season, during the dry season (November to April) steamship would not go upstream of Yên Bái; thus, during that part of the year goods were moved by small vessels (junks).
Thanks to the river, Haiphong was in the early 20th century the sea port most easily accessible from Kunming. Still, the travel time between Haiphong and Kunming was reckoned by the Western authorities at 28 days: it involved 16 days of travel by steamer and then a small boat up the Red River to Manhao (425 miles), and then 12 days overland (194 miles) to Kunming.
Manhao was considered the head of navigation for the smallest vessels (wupan 五版); so Yunnan's products such as tin would be brought to Manhao by pack mules, where they would be loaded to boats to be sent downstream. On the Manhao to Lao Cai section, where the current may be quite fast, especially during the freshet season, traveling upstream in an wupan was much more difficult than downstream. According to one report, one could descend from Manhao to Lao Cai in just 10 hours, while sailing in the reverse direction could take 10 days, and sometimes as much as one month.

## Dams

Several hydroelectric dams have been constructed on the Red River in Yunnan:
* Da Wan Dam
* Dachunhe I Dam
* Dachunhe II Dam
* Nansha Dam, near Nansha Town, Yuanyang County
* Madushan Dam, near Manhao Town, Gejiu City
Many more dams exist on the Red River's tributaries, both in Yunnan and in Vietnam. One of the earliest of them is the Thác Bà Dam in Vietnam, constructed in 1972, which forms the Thác Bà Lake.

## Settlements
### China (中國)

* Yunnan (雲南)
** Honghe (紅河)
** Nansha Town, the county seat of Yuanyang County, Yunnan (南沙鎮)
** Manhao Town (Gejiu County-level City) (蔓耗鎮)
** Hekou Yao Autonomous County (河口瑤族自治縣)

### Vietnam (Việt Nam)

* Hà Nội
** Tây Hồ district
** Ba Đình district
** Hoàn Kiếm district
** Hai Bà Trưng district
** Long Biên district
** Gia Lâm district
** Hoàng Mai district
** Ba Vì district
** Đan Phượng district
** Đông Anh district
** Mê Linh district
** Phúc Thọ district
** Phú Xuyên district
** Sơn Tây town
** Thanh Trì district
** Thường Tín district
** Từ Liêm district
* Hà Nam province
** Duy Tiên district
** Lý Nhân district
* Hưng Yên province
** Văn Giang district
** Khoái Châu district
** Kim Động district
** Hưng Yên
** Tiên Lữ district
* Lào Cai province
** Bảo Yên district
** Bảo Thắng district
* Nam Định province
** Nam Trực district
** Giao Thủy district
** Trực Ninh district
** Xuân Trường district
* Phú Thọ province
** Cẩm Khê district (old name: Sông Thao district)
** Hạ Hòa
** Lâm Thao
** Phú Thọ
** Tam Nông
** Thanh Ba
** Thanh Thủy
** Việt Trì
* Thái Bình province
** Hưng Hà district
** Vũ Thư district
** Kiến Xương district
** Tiền Hải district
* Vĩnh Phúc province
** Vĩnh Tường district
** Yên Lạc district
* Yên Bái province
** Trấn Yên district
** Văn Yên district