Vanishing Mekong? shifting tropical storms threaten a great river delta
Recent changes in the patterns of tropical storms are threatening the future of the Mekong River delta in Vietnam. This is one of the world’s great deltas. It is home to more than 20m people and the rice that is grown on its fertile land underpins food security across South-East Asia. Working with colleagues from the UK, US and Finland, we’ve just published a paper in Nature, which shows that fewer tropical storms have been hitting the Mekong catchment in recent years. This in turn results in much less mud and sand reaching the delta. We’re worried that this could have dramatic effects on the delta’s sustainability in the medium and longer term due to the adverse impacts on flooding and reduced agricultural productivity. The world’s deltas are facing a sustainability crisis: 28 of the 33 largest are at risk of “drowning” as a result of rising relative sea-levels. Deltas naturally sink slowly under their own weight, but under normal conditions the sediments supplied from the rivers that feed them are deposited, maintaining the delta surface above sea-level.
