UNDERSTANDING THE FLOW AND SEDIMENT DYNAMICS IN THE MEKONG RIVER – A CASE STUDY IN THE VINH LONG PROVINCE
T.N.Q. Nga1, D.N. Khoi2, N.T.D. Thuy2, D.T. Nhan2 , T.T. Kim3 and N.T. Bay1
ABSTRACT: River bank processes of erosion and accretion are influenced by both of natural processes and human activities. Therefore, understanding the riverbank processes plays an important role in erosion and accretion mitigations in the Vietnamese Mekong Delta. The objective of this study is to investigate the response of flow and sediment dynamics under impacts of sand mining, river encroachment due to the expansion of fish ponds, and hydrological alteration from the upstream area – a case study in the Mekong River in the Vinh Long province by using MIKE 21 FM model. The calibration and validation results indicated that MIKE 21 FM is one of reliable and reasonable tools for simulating the flow and sediment dynamics in the study area. The responses of flow and sediment dynamics under separate and combined impacts of the illegal sand-mining, river encroachment, and upstream hydrological changes were simulated based on the calibrated model. The results obtained in this study could be useful to propose mitigation measures for riverbank erosion and accretion for management and monitoring