Innovative vietnamese research on mekong deltaic coastal processes

Abstract

Over the last few decades, the Mekong Delta Coast has undergone many physical changes that have increased its vulnerability. Issues that have grown in importance are erosion, human occupation of coastal and estuarine mangroves, decreased sediment supply by the Mekong River and subsidence due to groundwater extraction. These issues have led to the loss of coastal and estuarine land and mangroves, increasing flood vulnerability and salinity intrusion. Recently, young and promising Vietnamese researchers have undertaken a number of in-depth studies to increase our understanding of the above issues. The objective of the present paper is to give a concise description of their work and place it into a broader context. The topics concerned are satellite mapping of coastal landuse changes, numerical simulation of the tide and wave climate and of coastal erosion, coastal and estuarine mangrove squeeze, wave and current damping in mangroves and wave transmission through bamboo fences. The main findings are that (1) coastal landuse has changed significantly over the last decades with the largest change due to conversion of mangroves to aquaculture and a modest change due to coastal erosion, (2) the understanding of the tide and wave climate and of the erosion has increased due to successful numerical modelling, (3) the role of mangrove squeeze along the coast and along the estuaries has been assessed, (4) the understanding of wave and current damping in mangroves and of wave transmission through bamboo fences has increased through the combined effort of laboratory and numerical modelling.