Song Hong or Red River or Yuan River is an important Asian river which flows for a distance of 1,140 km from Southwest China through Vietnam and drains into the Gulf of Tonkin. The source of the river lies in the mountains south of Dali in China's Yunnan province. After exiting China, the river enters Vietnam, and for a part of its flow, it acts as a natural border between China and Vietnam. The high loads of silt in the river lend a reddish-brown colouration to the waters of the river which gives it its alternative name of "Red River of Asia". Massive floods and water level fluctuations are often associated with the river. This unpredictable nature of the river necessitates the protection of land along the river by a network of dikes and levees. The Song Hong River has two major tributaries, the Black River and the Lo River.
In the 19th century, the Song Hong River was regarded a lucrative trade route in China, connecting the French IndoChina with the Yunnan. French explorers and traders would travel long distances via the Red River route to reach trade posts along the river. The river also connected Kunming to the sea port of Hai Phong. The crucial role of the river as a trade route, however, declined in 1910 when the Kunming–Hai Phong Railway was built.
The Song Hong River Delta is an economically significant area in Vietnam, housing a large number of industrial zones and nearly 19 million people. Hanoi, the capital city of Vietnam and the Haiphong port is located on the delta. The delta is one of the largest rice-producing areas in the country. Farmers also grow beans, corn, wheat, and other crops around the delta. Other commercial activities like fishing, aquaculture, mangrove forestry, etc., are also carried out here. Industrial zones like Hanoi, Viet Tri, Nam Dinh, and others are also located in the river delta. China also reaps large benefits by sending and receiving goods to and from Vietnam, respectively, through the river route.
Habitat and Biodiversity
The Song Hong River basin supports mangrove forests, dune vegetation, and salt marshes. Around 26 mangrove species are found in the mangroves of the region. A large number of migrant birds visit the region in winter. Spoonbill sandpiper, black-headed ibis, Japanese flycatcher, etc., are some of the threatened species of birds that can be sighted near the Song Hong River basin. The river also hosts saltwater crocodiles, sea cows, and fishes.
Environmental Threats and Territorial Disputes
Floods in the Song Hong River basin threaten vasts tracts of agricultural lands in China and Vietnam. Every year, farmers suffer significant crop losses due to such floods. Chemical and sewage dumping, over-fishing, soil degradation, etc., degrade the quality of the river's waters. There is thus an urgent need to conserve the river and protect it against pollution to ensure its aquatic ecosystem remains undisturbed.