Region of freshwater influence (ROFI) and its impact on sediment transport in the lower Mekong Delta coastal zone of Vietnam

Abstract

The delta of the Mekong River is one of the largest in the world, with the Mekong River carrying large amount of sediments in its Region of Freshwater Influence (ROFI). This study investigates the flow structure and movement of both suspended and bedload sediments in the ROFI of the Lower Mekong Delta (LMD) in order to identify areas prone to sediment accretion and erosion. This is accomplished by applying the three dimensional Coastal and Regional Ocean COmmunity (CROCO) model and then calculating the sediment budget of different stretches of the coastline. The model outputs, depicting areas experiencing sediment accretion and erosion along the coastline of the LMD, are then compared against observations obtained during the period 1990-2015 and demonstrate the ability of the model to identify areas particularly prone to erosion and where preventive actions against coastal erosion should focus.

Numerical Study on Measures for Protecting the Go-Cong Coastlines (Vietnam) from Erosion

“…Under the norteast wind, the outflow from the Soai-Rap estuary lightly sediment laden is directed towards the south, combined with wave action seriously erodes the Go-Cong coastline. From May to October, under the southwest wind and the region of freshwater influence (ROFI) of the VMD [10], the very turbid coastal flow coming from the Cua-Tieu and Cua-Dai estuaries creates accretions offshore rather than near the coast in the GCCZ. Some well-known protection measures have been investigated, analysed, and modified to apply to the Go-Cong Coastal Zone.…”

Wind‐Enhanced Separation of Large‐Scale River Plumes From Coastal Corners

“…In this high‐latitude region, the East Greenland Coastal Current interacts with the widely turning coast at Cape Farewell (Bacon et al., 2002; Sutherland & Pickart, 2008). Other global examples of plumes interacting with coastal corners are the Western Iberian plume at Cape Finisterre (Alvarez et al., 2011; Otero et al., 2008, 2009), the Mekong plume at Ca Mau Cape during the winter monsoon (e.g., Matsushita et al., 2022; Nguyen et al., 2022; Zeng et al., 2022), and the Ayeyarwady (Irrawaddy) plume at Mawtin Point (Liu et al., 2020; Sandeep & Pant, 2019). There are other pronounced coastal orientation changes near major rivers such as the Ob, Yenisei, and Yukon that influence wind response and plume behavior (Clark & Mannino, 2022; Frey & Osadchiev, 2021; Osadchiev et al., 2017).…”

The barotropic simulation of coastal current in Soc Trang derived from a hydraulic model in curvilinear coordinates

“…The coastal estuarine area in the Mekong Delta has undergone complex changes in its hydraulic regime due to climate change and upstream development [26]. The coast of Soc Trang has been extensively studied regarding the contribution of natural hydrodynamic sediment redistribution and erosion caused by human activities [25,[27][28][29][30]. Notably, a three-dimensional hydrodynamic redistribution model has been proposed to account for sediment movement from land, rivers, and other sources.…”