VNExpress-Sept 4
The Mekong Delta was only formed 6,000 years ago, thanks to alluvial accumulation from the Mekong River, which runs more than 5,000 km from China. The delta, home to the last 250 km of the river, became the third largest river basin in the world, though the youngest and far younger than the two larger basins, Bengal in India and Mississippi in the U.S., which have a history of hundreds of millions of years. The southern Vietnamese delta now spans over 40,000 square km and is home to 17.4 million people. It accounts for half of Vietnam’s rice output and 65% of its country’s aquaculture produce, and 17% of the GDP. Farmers depend on the river for their livelihoods, but it has become more vulnerable since the river’s wellbeing depends on impacts from upstream, and it is losing itself bit by bit for the past 20 years since the balance of alluvial addition and erosion was upset. Before 1990 the river carried an average 160 million tons of fine silt and 30 million tons of sand and gravel to the delta, a crucial supply of resources strengthening the river, its estuaries and more than 30,000 km of channels. But the supply has dried up in the last two decades, leaving the delta to suffer constantly from erosion. The Vietnamese delta is not only shrinking, it is also sinking, by more than 1 cm a year, three to eight times faster than the sea level rise. A study by Dr Rafael Schmitt of the U.S. Stanford University and his colleagues published in 2021 suggested that 23-90% of the delta will be under water by 2100. The rate will depend on the volume of sediments, groundwater available and rise in sea level. It means that in 80 years the area is likely to go back to how it was 6,000 years ago, gone and replaced by the sea. Read more at: https://e.vnexpress.net/news/news/environment/vietnam-s-mekong-delta-world-s-youngest-river-basin-might-be-first-one-gone-4648237.html
