Standing on the bank of the Mekong River, Tran Van Cung can see his rice farm wash away before his very eyes. The paddy's edge is crumbling into the delta.
Just 15 years ago, Southeast Asia's longest river carried some 143 million tons of sediment — as heavy as about 430 Empire State Buildings — through to the Mekong River delta every year, dumping nutrients along riverbanks essential to keeping tens of thousands of farms like Cung's intact and productive.
But as Chinese-built hydroelectric dams have mushroomed upriver, much of that sediment is being blocked, an analysis of satellite data by Germany-based aquatic remote sensing company EOMAP and Reuters shows.