Mangrove vegetation changes and shoreline erosion along the central coastline of Vietnam: A study from Quang Ngai province

Mangrove forests along the Vietnamese coastline provide multiple ecological, environmental, and economic services, including being a habitat for different flora and fauna, shoreline protection from erosion, storms, and waves, and providing several raw materials for industries. The coast of Quang Ngai province in Central Vietnam didn't get much attention from the research community, particularly on the mangrove reforestation programs and coastal environmental changes in the province. In the present study, we investigated the shoreline changes in Quang Ngai Province since the late 1980s, recent mangrove reforestation initiatives, and its progress in the area using medium-resolution Landsat imagery series and Sentinel-2 data. The results were compared with mangrove areas estimated from high-resolution RapidEye and PlanetScope imagery for accuracy analysis. There has been a slight increase in the area occupied by mangroves along the Quang Ngai coast between 2007 and 2022 compared to the area of mangrove patches in the 1980s. An increase in the area of inland mangroves offers various ecosystem services to the regional community, improvement in livelihood, and quality of environment. Our results indicated that the erosion-accretion changes along the coast of Quang Ngai were not unique and that some areas, such as the urbanized northern part, have eroded higher than southern areas except where sediment supply from larger rivers in the province is high. The mangroves planted in Bau Ca Cai wetlands indicated a success and such initiatives can be conducted throughout the south-central coast of Vietnam for long-term coastal protection.