Concept
The Red River Delta or Hong River Delta (Châu thổ sông Hồng) is the flat low-lying plain formed by the Red River and its distributaries merging with the Thái Bình River in northern Vietnam. Hồng (紅) is a Sino-Vietnamese word for "red" or "crimson". The delta has the smallest area but highest population and population density of all regions. The region, measuring some is well protected by a network of dikes. It is an agriculturally rich and densely populated area. Most of the land is devoted to rice cultivation. Eight provinces, together with two municipalities (the capital Hanoi, and the port of Haiphong) form the delta. It had a population of almost 23 million in 2019. In 2021, Paul Sidwell proposed that the locus of Proto-Austroasiatic languages was in this area about 4,000–4,500 years before present. The Hong River Delta is the cradle of the Vietnamese nation. Water puppetry originated in the rice paddies here. The region was bombed by United States warplanes during the Vietnam War. The region was designated as the Red River Delta Biosphere Reserve as part of UNESCO's Man and the Biosphere Programme in 2004. Quảng Ninh province, Bắc Giang province, Thái Nguyên province and Phú Thọ province are sometimes included as a province of the Red River Delta. Alternatively, they are seen as part of the Northeast region. Hà Tây province was merged into Hanoi in 2008. Spanning some 150 km in width, the Red River Delta is located in the western coastal zone of the Gulf of Tonkin. The Red River is the second largest river in Vietnam and one of the five largest rivers on the East Asia coast. Its catchment covers parts of China and Vietnam and its water and sediment discharges greatly influence the hydrology in the Gulf of Tonkin. In 2003, of the 78 million people in Vietnam, almost a third (24 million) live in the Red River basin, including over 17 million people in the delta itself. There are many large industrial zones in the Red River delta clustering in Viet Tri, Hanoi, Haiphong and Nam Dinh.
